tfnll1 FINAL TECHNICAL REPORT N J-1659 PRINCIPAL INVESTIGATORS: Sarah J. Cosgrove Research Assistant

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1 -, AD-A I il!tllrh fllllll11 tfnll1 FINAL TECHNICAL REPORT WORK UNIT NO: N14-9-J-1659 PROJECT TITLE: Thyroid Altertions In Porcine After Prolonged Exposure To Cold Or Het. PRINCIPAL INVESTIGATORS: Bruce A. Young, Ph.D * Professor of Animl Physiology Srh J. Cosgrove Reserch Assistnt Roert J. Christopherson, Ph.D Professor of Animl Physiology Deprtment of Animl Science University of Alert 31 Ag/Forestry Centre Edmonton, Alert Cnd T6G 2P5 Phone (43) Fx (43) (For further informtion plese contct S. Cosgrove) (* Present ddress, Animl Production Systems, Gtton College, University of Queenslnd, Lwes, QLD 4343, Austrli.) ~3- I6O12 t ; 7.

2 SECURITY CLASSIFICATION OF THIS PAGE I. REPORT SECURITY CLASSIFICATION JF REPORT DOCUMENTATION PAGE l. RESTRICTIVE MARKINGS UNC. 2. SECURITY CLASSIFICATION AUTHORITY 3. DISTRIBUTION/ AVAILABILITY OF REPORT Approved for pulic relese; 2. OECLASSIFICATION/DOWNGRADING SCHEDULE distriution is unlimited 4. PERFORMING ORGANIZATION REPORT NUMBER(S) 5. MONITORING ORGANIZATION REPORT NUMBER(S) NMRI NAME OF PERFORMING ORGANIZATION 6. OFFICE SYMBOL 7. NAME OF MONITORING ORGANIZATION Nvl Medicl Reserch (If pplicle) Nvl Medicl Commnd Institute I 6c. ADDRESS (Ciy, Stte, nd ZIP Code) 7. ADDRESS (City, Stte, nd ZIP Code) 891 Wisconsin Avenue Deprtment of the Nvy Bethesd, MD Wshington, DC NAME OF FUNDING/SPONSORING 8. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION Nvl Med i cl (if pplicle) Reserch & Development Commn Be- ADDRESS (City, Stte, nd ZIP Code) 1. SOURCE OF FUNDING NUMBERS 891 Wisconsin Avenue PROGRAM IPROJECT ITASK WORK UNIT Bethesd, MD ELEMENT NO. NO. NO. ACCESSION NO N MM33C DN TITLE (Include Security Clssifiction) Thyroid ltertions in porcine fter prolonged exposure to cold or het 12. PERSONAL AUTHOR(S) Young BA, Cosgrove SJ, Christopherson RJ 13. TYPE OF REPORT I13. TIME COVERED j1.date OF REPORT (Yer, Month, Dy) S.PGCON Technicl Rgpnrt I FROM TO SUPPLEMENTARY NOTATION Ir 17. COSATI CODES 18. SUBJECT terms (Continue on reverse if necessry nd identify y lock numer) FIELD IGROUP SUB-GROUP Porcine (pigs); thyroid; thermogenesis; oxygen consumption; hot climtes or cold climtes 19. ABSTRACT (Continue on reverse if necessry nd identify y lock numer) DTIC ELECTE.. DISTRIBUTION(AVAILABILITY OF ABSTRACT 21. ABSTRACT SECURITY CLASSIFICATION IUNCLASSIFIEDAJNUMITED SAME AS RPT QDTIC users Unclssi fied.2. NAME OF RESPONSIBLE INDIVIDUAL 22. TELEPHONE (Include Are Code) 22c. OFFICE SYMBOL Phyllis.8)um,"" Lirrin. (31) M -RL/NM-RI ) FORM 1473,84 MAR 83 APR edition my e used until exhused. SECURITY CLASSIFICATION OF THIS PAGE All other editions re osr!-*e UNCLASSI FI ED

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4 INTRODUCTION Studies y the Nvl Medicl Reserch Institute on humns fter prolonged ntrctic residence hve shown possile intrcellulr thyroid hormone ltertions. These studies demonstrted rise in serum clernce of orlly dministered triiodothyronine (T 3 ), T 3 production nd T 3 totl volume distriution in nvl personnel fter 42 week residence in Antrctic compred to control period in Cliforni (21). The incresed serum clernce nd totl pool of T 3 indicted possile intrcellulr response which could not e further investigted using humn sujects. An niml model permitted prolonged confinement of sujects in temperture controlled chmers nd the use of rdioisotopes to lel T 3. Pigs re suitle sustitute for humns eing ntomiclly nd physiologiclly similr. They hve furless skin, little or no rown ft nd depend, in prt, on shivering thermogenesis for cold tolernce (11) s do humns. Also pigs hve demonstrted physiologicl djustments for survivl in the cold (19). Rts, however, which hve een used extensively for cold studies, hve demonstrted n dptive non-shivering thermogenesis ssocited with modultion of rown ft y the sympthetic nervous system, under permissive control of thyroid hormone (2), ut with different peripherl profile during prolonged cold exposure compred to humns (2). The purpose of this study hs een to develop suitle porcine model in order to investigte the effects of prolonged exposure to cold or het on T 3, its response, distriution nd intrcellulr kinetics, nd its physiologicl consequences. IMATERIALS AND METHODS This coopertive study etween the University of Alert nd the Nvl Medicl Reserch Institute (NMRI) hs een pproched in two studies cver two yer period. 199 STUDY Twelve young-dult mle pigs, ( Cmorough, Pig Improvement Cnd Ltd.) kg in weight were confined individully in stinless steel metolism crtes, six to ech chmer, throughout the experimentl period. The crtes hd floor re of 1.5m 2 constructed of metl rods 12.7cm prt, 65cm from the chmer floors, with plexiglss sides. The chmers hd ir volumes of 143m 3 (wrm) nd 95m 3 (cold). They received stndrd pig grower rtion (16% crude protein, 3241 Kcl/Kg gross energy, 92% dry mtter) d-li nd free ccess to wter. Lights were mintined t 12 hours on, 12 hours off. The pigs were preconditioned to the experimentl surroundings nd humn hndling efore ny mesurements were tken. During preconditioning, nd for two further weeks when mesurements commenced, the climte chmers were mintined t 22*C. A trnsition week followed, during which the cold chmer temperture ws lowered 3 stedily to rech 5*C. The chmers were then mintined t 51C (cold) nd 22'C (wrm) for six weeks. Food intke ws recorded dily nd the pigs were weighed weekly. Oxygen consumption, mesured using n open circuit clorimetry system, ws recorded for 2] 2Ai Cnde/or Dist,Speoml

5 A selected nimls in rottion throughout the experiment. The niml nd its metolic crte were enclosed in n ir-tight plstic hood. From the flow of ir from the hood, nd the composition of the ir entering nd leving the hood, the level of oxygen uptke nd from this, the metolic het production nd energy lnce could e clculted. During week four the pigs were fsted for 24 hours nd lood smples were tken for hormone ssy. The pigs then underwent surgery under generl nesthesi, using I ml/kg odyweight of Stresnil I.M. to sedte followed y 1 ml/kg odyweight Hypnodil I.V. nd 2% Hlothne oxygen gs mixture, to insert two Silstic ctheters into the externl jugulr vein. Two ctheters were required one long, 28cm insertion for injection, the other short, 23cm insertion for smpling. Postopertive recovery ws oserved efore experimentl procedures continued. Ctheters were flushed dily with 2 ml of heprinized sline, 2 i.u./ml, to keep them ptent. Blood smples were tken fter recovery from surgery. These nd the fsted pre-surgery smples were llowed to clot, centrifuged ( 1 x g, 1 minutes) nd the seprted serum ws ssyed for totl T 3 (tt 3 ), free T 3 (ft 3 ), totl T 4 (tto), free T4 (ft 4 ), nd thyroid stimulting hormone (TSH) using Cot--Count Rdioimmunossy kits (Dignostic Products Corp. Los Angeles, CA.). Hemtocrits were mesured y micro-centrifugtion. Body composition nd plsm volume were mesured during the fifth week of tretment. A olus of tritited wter, 3HZO ( New Englnd Nucler, Wilmington, DE; specific ctivity 7.27 micro Ci/g) 3 uci/pig nd known concentrtion of Evns Blue dye expressed s dose per litre, were injected into ech niml. Timed serum smples were collected pre injection nd t 2, 6, nd 24 hours fter. The smples were counted in Pckrd Tri-cr counter to determine 3H 2 ctivity, nd Evns Blue dye concentrtion ws mesured in spectrophotometer. Totl ody wter, from the 3H 2, nd plsm volume from the Evns Blue dye, were clculted y extrpoltion of these concentrtions to time of injection. Body composition including wter, protein, ft, nd sh content were lso clculted, using the equtions of Ferrel nd Cornelius (7). T 3 kinetics studies to determine the serum clernce rte of T 3 were crried out on four pigs dy, two from the cold chmer, two from the wrm, during week five. On the dy prior to injection ech pig received 25 mg of potssium iodide on pple slices twice dily, to lock thyroid glnd uptke of iodine. The isotope, L-3,5,3 '-[12511 ]- triiodothyronine ( New Englnd Nucler, Wilmington, DE; specific ctivity 22 Ci/mmol) ws sterilized y filtrtion through.2 micrometer filter (Milipore corp, Bedford, MA). High pressure liquid chromtogrphy showed there to e less thn 2% free or orgnic iodide contminnts. Five minutes efore injection the rdiolelled [12511 T 3 ws diluted to 5 ml with 1% utologous serum nd dministered to ech niml s olus injection of 8OuCi. This ws flushed with n equl volume of heprinized sline. Blood smples of 6ml were tken t.8,.25,.5,.75, 1., 1.5, 2., 2.5, 3., 4., 8., 24 nd 48 hours fter injection. Smples were llowed to clot nd serum ws seprted y centrifugtion ( 1 x g, 1 minutes) nd stored t -7 C. The extrction nd counting of lelled T 3 ws crried out t the Nvl Medicl Reserch Institute. T 3 distriution ws mesured in four pigs per dy during week six, four or five dys fter receiving their first ['1 5 1]T 3 injection. There is virtully complete ody clernce of [1 25 1]T 3 in the pig y 72 hours. A lood smple ws tken prior to injection of 8uCi into ech niml s for the kinetics studies. 3

6 The nimls received 25mg of potssium iodide twice dily s efore. Ech pig ws scrificed four hours following the [1 2 I1T 5 3 dministrtion y injection of.3mg/kg odyweight T-61 (Hoechst Regin, Ssk.). The niml ws then dissected nd the wet weights of vrious orgns were recorded. Smples were tken from rnge of tissues nd orgns nd were weighed, dried to determine % dry mtter (DM) nd counted in the Pckrd Tri-cr counter. The smples were lter nlyzed using kjeldhl digestion to determine crude protein nd ether extrction to determine ft content (1). Smples of liver nd thyroid glnd were lso tken nd frozen t -7'C within 2 minutes of scrifice. The mesurements of I-5'D kinetic prmeters were crried out t the Nvl Medicl Reserch Institute STUDY Sixteen young-dult mle pigs 46-69kg in weight were confined individully in metolism crtes, six in two of the chmers nd four in the third. The wrm chmer nd cold chmer were s previously descried. The hot chmer hd n ir volume of 76m 3. The nimls received lower energy diet thn the firsz yer, grower mix diluted with 5% lflf (12% crude protein, 2646 Kcl/Kg digestile energy, 88% dry mtter), to slow their growth rtes slightly. The nimls received two week pre-conditioning followed y two weeks when ll chmers were kept t 221C. During this period ody composition ws mesured using 3H 2. A second mesure of this ws mde during week six of the temperture tretment. Food intke ws recorded dily, nd for one full week ll feces were collected nd weighed, nd smples were tken for nlysis. Dry mtter % of feed nd feces were clculted, nd the energy content of feed nd feces ws mesured using om clorimeter. From this dt, energy lnce or feed digestiility, energy going in per grm DM, minus energy lost per grm DM, could e clculted. A second digestiility study ws conducted during week four of temperture tretment. Oxygen consumption ws mesured on selected nimls throughout the experiment s efore. After trnsition week when tempertures were stedily lowered or rised, the three chmers were mintined t 22*C (wrm), 5 C (cold) nd 4 C (hot) for seven weeks. During weeks one to four of temperture tretment three nimls t once underwent cute hot ir tests (AHATs) or cute cold ir tests (ACATs) in rottion. Control mesurements of rectl temperture, side temperture, er temperture, hert rte nd respirtion rte were mde on one niml from ech tretment in its own environment. For n AHAT, the pig from the wrm nd pig from the cold chmer were put into moile metolic crtes nd moved into the hot room. The sme physiologicl mesurements were mde on ll three nimls in the hot, with the hot pig cting s control, fter 3 minutes nd 6 minutes. The nimls were then returned to their own chmers. For n ACAT, the pig from the wrm nd the pig from the hot chmer were moved into the cold chmer for n hour. The chnge in the physiologicl prmeters mesured during n cute (one hour) exposure to n extreme in temperture could then e clculted. The nimls underwent surgery under generl nesthesi s efore except tht the injection nd smpling ctheters were inserted one into ech of the externl cephlic nd internl cephlic veins. These led into the jugulr vein nd in effect the ctheters were in the sme loction s efore. The ctheters were seprted into two veins nd the cephlic cnnultion, less tissue invsive thn the jugulr cnnultion, ws used to minimise risk of infection due to surgery. In week six of tretment lood smples were tken from ech pig immeditely 4

7 efore nd fter 24 hour fst. The serum ws seprted nd ssyed for tt 3, ft 3, tt 4, ft 4, s for the first yer smples, nd lso ssyed for testostetone concentrtion. All ssys were done using Cot--Count rdioimmunossy kits. Blood smples tken t this time were lso sent to commercil medicl lortory for lood chrcteristion nd metolite nlysis including white nd red lood cell count, hemogloin level, clcium, phosphorous, glucose, protein, ure nd cholesterol concentrtion. The T 3 kinetics study ws crried out during week six using the methods descried for yer one. This ws followed y T 3 distriution study s efore for which the pigs were scrificed. Smples of muscle (iceps) nd liver were removed from ech niml within minutes of scrifice nd stored for minimum length of time in kres icronte uffer. Live tissue oxygen consumption ws the mesured on these smples using Clrk cell pprtus ( Yellow Springs Interntionl). Anlysis of tretment effects ws undertken y nlysis of vrince using the SAS sttisticl pckge. RESULTS Group men dily food intke ws incresed in the cold (+4% yer 1), (+47% yer 2) nd decresed in the hot (-33%) (Figure 2, Figure 3). When totl food intke ws compred to totl weight gin over the experimentl period, it ws seen tht nimls in the cold hd the highest food intke for the lowest gin in odyweight (Figure 4), food conversion rtio of.13 compred to.24 nd.25 in the wrm nd hot groups respectively. There were no significnt chnges in ody weight or composition over the time spent in the cold or in the hot (Figure 2, Figure 3, Figure 5). In the first yer study, cold exposed nimls hd significntly hevier thyroid glnds nd kidneys, s percentge of ody weight (Tle 2). No differences in orgn weights were seen in the second yer. No significnt tretment differences were seen in the composition of liver, thyroid nd muscle tissues mesured in the first yer study. There were significnt chnges in the thyroid hormone levels. Serum concentrtions were higher in the cold exposed nimls (tt 3 +96% nd +21%, ft % nd +36%, tt 4 +68% nd +11%, ft 4 +49% nd +7%), nd lower in the hot group (tt 3-44%, ft 3-25%, tt 4-11%, ft 4-2%), compred to nimls kept in the wrm group (Figure 6). No chnge however ws oserved in TSH levels ( Figure 7). Fsting ws seen to reduce tt 3, ft 3, ft 4 nd TSH in ll nimls over oth yers. In the hot treted nimls tt4 ws lso reduced. Within the fsted smples tt 3 tt 4 nd ft 4 were significntly higher in the cold thn in the wrm (+11%, +52%, +1% respectively) during the first yers study only (Figure 8). Animls in the hot room hd lower fsted levels of tt 4 (-2%) nd ft 4 (-31%) thn those in the wrm. Serum testosterone ws lower in the cold exposed nimls, (-83% fed, -2% fsted) (Figure 9). However fsting incresed serum testosterone under ll temperture tretments (+341% wrm, +189% cold, +324% hot). Men group totl oxygen consumption incresed (+25%) in the cold exposed nimls (Figure 7), nd tissue oxygen consumption incresed in muscle from the cold exposed nimls nd decresed in muscle from nimls kept in the hot (Figure 1), however none of these oservtions were sttisticlly significnt. A slight reduction in food digestiility ws lso seen in the cold (Figure 1) ut gin this ws not significnt. Totl ody wter, lood volume nd plsm volume were not ltered y 5

8 temperture tretment (Figure 11) however hemtocrit ws seen to e significntly incresed (+6%), y cold tretment. When lood chrcteristics nd metolite levels were mesured no significnt chnges were seen in white lood cell count, clcium level, glucose level or ure level (Figure 12). However cold exposed nimls were seen to hve significntly higher red lood cell counts (+16%), hemogloin levels (+13%), phosphorous levels (+14%) nd lumen levels (+11%). Hot tretment ws seen only to decrese lumen levels (-17%). Serum cholesterol levels were significntly higher (+21%) in the cold treted nimls. Fsting ws seen to increse cholesterol levels in ll temperture tretments (+49% wrm, +18% cold, +3% hot) (Figure 9). After severl weeks dption to the different tempertures, little ltertion in rectl temperture, s n indiction of core temperture ws seen, lthough drop ws mesured in the cold during the first yer study (Figure 13). Side temperture nd er temperture clerly fell (-13% nd -23% side, -47% nd - 41% er) in the cold exposed nimls nd rose (+21% side, +36% er) in the hot exposed nimls compred to those in the control, wrm room. A smll fll of hert rte (-14%) ws seen in the hot nimls. Respirtion rte fell in the cold (-39%) nd incresed in the hot (+133%). During the hour long cute cold tests, wrm nimls did not undergo ny chnges significntly different to the cold nimls lredy present, in ny of the physiologicl criteri (Figure 14). Animls from the hot room however on verge showed significnt decreses in rectl (-.5'C), side (-12.8'C) er (- 22.1'C) temperture, nd respirtion rte (-59 reths/min). During the cute hot tests, oth nimls from the wrm room nd cold room showed rises in rectl (+1.6 nd +1.2 C), side (+6.9 nd +15*C) er (+9.7 nd C) temperture nd respirtion rte (+92 nd +73 reths/min), significntly higher thn the het dpted nimls. The incresed levels mesured in the cold nimls were lso significntly greter thn those in the wrm nimls. No chnges were seen in hert rte, proly due to the lrge vrition in response. DISCUSSION Mny studies hve shown tht exposing nimls to fll in mient temperture results in n incresed rte of production nd utiliztion of thyroid hormones (6,8,15), nd exposing nimls to n incresed mient temperture decreses rte of thyroid hormone production (15,3,14). This rise in the cold of thyroid hormones ws seen in the first yer study, nd fll in the het in the second yer. The gretest increses nd decreses were in thyroxine, T 3 levels, s the iologiclly ctive form. T 4 cn e converted to T 3 y deiodintion t the 5' position, so T 4 levels ct s uffer for rpid T 3 chnges. No significnt differences in thyroid hormone levels etween cold nd control groups were seen in the second yer, lthough the trend ws there. In the second yer nimls were fed diet high in lflf in n ttempt to reduce growth rtes. This did not hppen ecuse the nimls compensted y eting more. Food intke ws therefore higher in the second study. The incresed fire in the diet genertes more het s y-product of digestion (23) nd this could hve een used to reduce het production requirements in the cold. To meet the incresed or decresed energy demnd for het production in the cold or hot, food intke will e incresed or decresed when ville (13,3,14,6). This ws seen in our pigs. There is some dete s to whether it is the incresed energy demnd tht cuses the djustment of food intke nd tht this in turn hs n effect on thyroid hormone levels, or whether it is the 6

9 thyroid hormones tht stimulte the food intke djustment. Evns nd Ingrm (6) hve suggested tht the initil rise in thyroid hormone is in response to n initil increse in TSH, due to temperture receptor stimultion, ut tht the ility to increse food intke is wht mintins elevted hormones nd TSH returns to control levels vi feedck. Our nimls showed no response in serum TSH fter severl weeks in the cold. Also fsting cused decrese in thyroid hormones in ll temperture tretments, nd in the second yer study temperture tretment differences seen in T 3 hot pigs were removed. Animls on the second yer study high fire diet my hve experienced clorific restriction which limited the thyroid hormone response to cold. Mcri et l (18) concluded from their work tht the djustment in food intke during cclimtion could e dependnt on thyroid hormone levels, from looking t the response in thyroidectomized swine. The reltionship etween nutrient intke nd thyroid function is clerly complex. Food digestiility hs lso een shown to decrese in the cold (9) however this is less predictle in swine thn in ruminnts nd ws not oserved in this study. Associted with rise in thyroid hormone levels is rise in metolic rte. This results in incresed het production to meet ody needs in the cold. When this increse in energy demnd is coupled with d-li food intke, ody composition cn e mintined. No chnges in wter ft or protein content due to temperture tretment were seen in our study. Some workers hve seen chnges (5,1) when young or restrict fed swine were used. Our men group ody weights did not differ etween tretments, however overll gin ws reduced in the cold despite elevted food intke. Food conversion efficiency in the cold ws low since extr energy ws chnnelled into het production rther thn ody growth. Some workers hve seen chnges in certin orgn weights (24). In the first yer study thyroid weight nd kidney weight s percentge of odyweight were incresed in the cold, possily indictive of incresed ctivity of these orgns, however no chnges were seen in the drenls or liver. The ft wter nd protein content of muscle, liver nd thyroid tissues were lso unchnged y temperture. Ad-li feeding proly protected these ody tissues. Totl oxyge. consumption of the rimls lso increses in the cold s metolic rte rises (15) nd muscle oxygen consumption hs lso een seen to increse (12). These trends were evident in our study ut were not sttisticlly significnt. Hemtocrit, red lood cell count nd hemogloin levels in the cold exposed nimls were ll incresed. These mechnisms would ll increse the efficiency of oxygen trnsport s demnd incresed. Hert rte would hve lso een expected to increse ut this ws not cler due to lrgo vrition in the dt. Animls strtled y hndling would hve hd higher hert rte nywy. Cold temperture hs een known to reduce plsm volume nd totl ody wter. Vsoconstriction results in less plsm volume required for circultion. This lso contriutes to the increse seen in hemtocrit. Some prolems with methodology were proly responsile for the lck of chnge in ody fluids oserved. A depression in circulting lymphocytes nd n increse in heterophilic grnulocytes hs een shown s stress response in chickens (22). The rtio of these were nlyzed in this study ut no chnges in white lood cells were oserved in cold or het. Circulting lumen cn ct s inding protein for thyroid hormones. A cler increse in the cold nd decrese in the hot ws seen, suggesting tht the chnge in lumen level could hve een ssocited with chnges in thyroid hormones. 7

10 Testiculr size nd level of steroidogenesis cn e reduced y drenl corticosteroids cting to lower plsm interstitil cell stimulting hormone (16). In swine testosterone hs een shown to respond differently to n cute chnge in corticosteroids s opposed to longer term chnge (17). In the cold, long term stress my hve cused the depression in circulting levels oserved. When the nimls were fsted for 24 hours, drmtic increse in testosterone ws seen in ll temperture tretments. Injection of ACTH in ors hs een shown to rpidly increse testosterone (17), nd this rise my hve een cused y the cute stress of fsting. Thyroid hormones re known to increse oth production nd clernce of cholesterol. Fed nimls in the cold showed higher circulting levels, whilst fsting nimls showed no temperture effect. Fsting cholesterol ws rised possily ecuse the fll in thyroid hormones reduced the rte of clernce, so despite lower production, on lnce, serum levels were higher. Generl moiliztion of ody ft reserves could lso hve contriuted to the higher levels in the cold. Rectl temperture hs een shown to decrese in cold cclimted pigs in some cses (12) ut not in others (4). If the nimls re old enough nd hve ccess to food they re more likely to mintin their core ody temperture. A response in the cold ws seen in the first yer study ut not in the second. A rise in rectl temperture ws seen in the hot tretment group. Cler chnges were mesured in skin temperture, oth on the flnk nd er in the hot nd cold. Lowering the temperture of the outer ody shell effectively increses therml insultion of the core (11). In cses where fll in rectl temperture hs occurred, it hs een suggested tht this could e possile dptive mechnism in the cold, nd tht slight decrese in Dody temperture decreses the metolic demnd on the niml (11). Vsoconstriction drws lood wy from the extremities, prticulrly the ers, where lrge surfce re in swine would hve high potentil for het loss. In the het, skin surfce, oth on er nd flnk, rose lmost to rectl temperture s lood circulted close to the skin surfce to mximise het loss. Respirtion rte incresed in the hot group s the pigs were pnting. Behviorl chnges were seen. Animls in the hot room spent little time stnding or moving nd most of the time lying stretched out. Conversely pigs in the cold spent lot of time on their feet or lying with legs tuck-d under to minimise exposed skin re. When nimls were put through the ACATs nd AHATs, the mgnitude of chnge in the physiologicl prmeters ws considered. For hot nimls in AHATs nd cold nimls in ACATs this chnge should hve een nd ws very smll over the hour. Any chnges mesured were proly due to the limit of ccurcy of the thermometers. In the ACATs, pigs from the wrm group did not undergo ýignificnt chnges in temperture over the hour. Animls from the hot group however did. The hot group respirtion rrp lso fell in the cold. In AHATs oth the wrm nd cold pigs underwent signifi. chnges in rectl nd skin temperture over the hour, with cold cclimted pigs showing the gretest chnge. The igger the grdient in environmentl chnge tht the pigs were exposed to, the igger ws the response seen. The nimls hd cclimted to their tretment tempertures nd hd to ctivte rpid mechnisms to cope with the chnge in environment. Overll oth yers of the study were successfully completed, using swine s model to investigte the effects of prolonged exposure to cold nd het on thyroid function nd its physiologicl consequences. Mteril for the joint prt of the study on intrcellulr kinetics of thyroid hormone response ws lso successfully collected nd processed t the Nvl Medicl Reserch Institute. 8

11 There is now clerer picture of the consequences of sttioning nvl personnel for long periods in cold or hot climtes, wht the chnges in iologicl demnds will e Ld wht stresses will e involved in moving them rpidly from one extreme climte to nother. 9

12 REFERENCES 1. Assocition of Officil Anlyticl Chemists. (1984) Officil Methods of Anlysis, 14 th ed. AOAC, Wshington, D.C. 2. Binco, A.C. & Silv, E.A. (1988) Am. J. Physiol. 255;E496-E Christon, R. (1988) J. Anim. Sci. 66; Close, W.H. & Mount, L.E. (1978) Br. J. Nutr. 4; Duncy, M.J. & Ingrm, D.L. (1985) J. Agric, Sci. (Cm.) 11; Evns, S.E. & Ingrm, D.L. (1977) J. Physiol. 264; Ferrel, C.L. & Cornelius, S.G. (1984) J. Anim. Sci. 58; Freinkel, N. & Lewis, D. (1957) J. Physiol. 135; Fuller, M.F. & Boyne, A.W. (1971) Br. J. Nutr. 75; Hcker, R.R., Stefnovic, M.P. & Btr, T.R. (1973) J. Anim. Sci. 37; Heldmier, G. (1974) J. Appl. Physiol. 36; Herpin, P.R., McBride, B.W. &Byley, H.S. (1987) Cn. J. Physiol. Phrmcol. 65; Ingrm, D.L & Legge, K.F. (1974) Comp. Biochem. Physiol. 48; Ingrm, D.L. (1977) Pflug. Arch. Eur. J. Physiol. 367; Ingrm, D.L. & Sleodzinski, A.B (1965) Res. Vet. Sci. 6; Liptrp, R.M. & Reside, J.1. (1968) J. Endocrinol. 42; Liptrp, R.M. & Reside, J.1. (1975) J. Endocrinol. 66; Mcri, M., Zuim, S.M.F., Secto, E.R. & Guerreiro, J.R. (1986) J. Physiol. Behv. 36; NRC. Effect of Environment on Nutrient Requirements of Domestic Animls. (1981) Ntionl Acdemy of Science, Wshington, D.C. 2. Reed, H.L., Ferreiro, J.A., Shkir, K.M., Burmn, K.D. &O'Brien, J.T. (1988) Am. J. Physiol. 254;E733-E Reed, H.L., Silvermn, E., Shkir, K.M., Burmn, K.D., Dons, R. & O'Brien, J.T. (199) J. Endo. Met. 7; Siegel, H.S. (1985) WPSA J. 41;

13 23. Sthly, T.S. & Cromwell, G.L. (1986) J. Anim. Sci. 63; Sughr, K., Bker, D.H., Hrmon, B.G. & Jensen, A.H. (197) J. Anim. Sci. 31;

14 M W-4 1 M u Iq c- oc cc4 z 1U 8 w, >- LC XCDCCn z' U) w D LUL LU LLJJ ui- Kw I- CU w CU) C- w z. o L). M CC : cn D w u F- 3r.

15 Figure 2 LIVE BODYWEIGHT i- 199 STUDY cm le S41 * 2 Ferury Mrch DAILY FEED INTAKE STUDY :1 3 - m P- 21I i Ferury Mrch WARM CD COLD Different Superscripts Indicte Significnce AtC P<.5

16 Figure 3 LIVE BODYWEIGHT STUDY '21 "o 4 " m '- Jnury Ferury Mrch DAILY FEED INTAKE STUDY Cm 4- m 3- B l I=,, 2 - CC C : V/ //I Jnury Ferury Mr ch U WARM n COLD n HOT Different Superscripts Indicte Significnce At P<O.5

17 Figwre 4 TOTAL LIVEWEIGHT GAIN STUDY 5- C D 3- Cn S4- CD -,1 2- to - TOTAL FEED INTAKE STUDY 2.5- S2- C CU U- O.-- ' U WARM COLD HOT Different Superscripts Indicte Significnce At P<.5

18 Figure 5 BODY COMPOSITION 199 STUDY WATER 55% WATER 54% OTHER 3% OTHER 4% ASH 31 ASH 3% FAT 22% PROTEIN 17% FAT 22% PROTEIN 17% WARM COLD BODY COMPOSITION 1991 STUDY WATER 55% WATER 55% OTHER 4% OTHER 4% n4x'ash 3% ASH 3% FAT 21% PROTEIN 17% FAT 21% PROTEIN 17% WARM WATER 56% COLD OTHER 3% ASH 3% FAT 21% PROTEIN 17% HOT

19 Figure 6 z THYROID HORMONES STUDY rr z "LU z I W z.5 tt3 (ng/ml) tt4 (ug/ml x i) ft3 (pg/ml) ft4 (ng/ml x 1) THYROID HORMONES STUDY z C.5 - LUj "Z / m tt3 (ng/ml) tt4 (ug/ml x 1) ft3 (pg/ml) ft4 (ng/ml x 1) * WARMO] COLDE2 HOT Different Superscripts Indicte Significnce At P<O.5

20 Figure THYROID STIMULATING HORMONE 199 STUDY 3- Lo 2- i- TOTAL OXYGEN CONSUMPTION 199 STUDY CU S4-2- Ferury Mrch EWARM mocold Different Superscripts Indicte Significnce At P<O.5

21 Figure 8 "m THYROID HORMONES - FASTED LEVELS 199 STUDY J -.6- U U.4- - d) C- C3. w tt3 (g/ml tt4 (ug/ml x ) ft3 (pg/ml) ft4 (ng/ml x 1) C- I THYROID HORMONES - FASTED LEVELS 1991 STUDY.8- ///- S.4- - i m 1991 STUDY- 1 "t tt3 (ng/ml) tt4 (ug/ml x 1) ft3 (pg/ml) ft4 (ng/ml x 1) T RARM E M COLD F HOT Different Superscripts Indict~e Significnce At P<.5

22 Figure 9 Testosterone Levels In Fed nd Fsted Bors, CU 4T Li E 2- Wrm Cold Hot Temperture Tretment N Fed [ Fsted Gifferent superscripts indicte significnce t p<.o1 Cholesterol Levels in Fed nd Fsted Bors 4 - S3 C m 2- T C- = 1 9 C-, CU Wrm Cold Hot Temperture Tretment I Fed 5 Fsted Offerent suoerscriots indicte significnce t :<.5

23 Figure 1 E 5 TISSUE OXYGEN CONSUMPTION 1991 STUDY, 2 L4 C -! z 3 - m 2- z z LU CD MUSCLE TISSUE TYPE LIVER -J4- FEED DIGESTIBILITY 1991 STUDY 'I -3 3 U, Lo " U WARM C COLD E HOT Different Superscripts Indicte Significnce At P<O.5

24 Fi gur,, Ii BODY FLUIDS STUDY I-- 51 "I' 4- -o 3-2- t, BLOOD VOL PLASMA VOL HEMATOCRIT BODY H2 BODY FLUIDS STUDY 5- S (, ot BLOOD VOL HEMATOCRIT BODY H2 WARM M COLD C HOT - Different Superscripts Indicte Significnce At P<O.5

25 ( E EiE c') LC. F-I w C) ol.- CL --.. in 4-.' u CL ~cn LL ' <N C.l(. oo m Co _oce U (1) - 1. r4uc CD Co C (. P-4 CD.. LU" M - Q Lu cucr uoi~ejuouo Co c 3C cm~

26 :igure 13 PHYSIOLOGICAL ADAPTATION TO ENVIRONMENT 199 STUDY 4 - C 1 (n, I CC- 2 - S3 U En 1 Rectl Temp (C) Side Temp (c) Er Temp (C) PHYSIOLOGICAL ADAPTATION TO ENVIRONMENT STUDY, U, C1 8- C : /7 C', m 2 - "//) / V/ / 2 rii. VA/ Rectl Tmp (C) Side Temp (C) Er Temp (C) reuth/min Hert Rte tp/to) * WARM E COLD O HOT Different Superscripts Indicte Significnce At P<.5

27 Figure 14 ACUTE COLD AIR TEST (I hour) i STUDY // C-1 C Rectl Temp (C) Side Temp (C) Er Temp (C) Hert Rte (pmj Breths/min/lO ACUTE HOT AIR TEST STUDY (1 hour) 2- tn S 1 Cm m 5- C -5 Rectl Temp (C) Side Temp (C) Er Tmp (C) Hert Rte (pm) Breths/.in/iO N WARr',i COLD o HOT Different Superscripts Indicte Significnce At P<O.5

28 Tle I ROOM TEMPERATURE 199 STUDY WARM ROOM COLD ROOM JANUARY MAX C MIN C 2.2 i9.i RH% FEBUARY MAX C MIN C RH% MARCH MAX C MIN C RH% ROOM TEMPERATURE 1991 STUDY WARM ROOM COLD ROOM HOT ROOM JANUARY MAX C MIN C RH% FEBUARY MAX C MIN C RH% MARCH MAX C MIN C RHX

29 Tle 2 ORGAN WEIGHTS 199 STUDY WARM ROOM COLD ROOM WET WEIGHT THYROID /g KIDNEY /g ADRENALS /g I.i % BODYWEIGHT THYROID /g.12.o3.2.5 KIDNEY /g.431 +o.o , ADRENALS /g ORGAN WEIGHTS 1991 STUDY WARM ROOM COLD ROOM HOT ROOM WET WEIGHT THYROID /g KIDNEY /g * ADRENALS /g o o % BODYWEIGHT THYROID /g.1i *.2.12* KIDNEY /g * *.17 ADRENALS /g.4 +o.oog.5*.2.5 L.2 * Indicte Significnce At P<O.5