Interspecific Effects of Amino- Dinitrotoluene Exposure

Transcription

1 Interspecific Effects of Amino- Dinitrotoluene Exposure Crig A. McFrlnd Michel J. Quinn, Jr. Emily M. LFindr Mtthew A. Bzr Lrry G. Tlent Mrk S. Johnson US Army Center for Helth Promotion nd Preventive Medicine Helth Effects Reserch Progrm Oklhom Stte University

2 Amino-Dinitrotoluene (A-DNT) Rpidly formed from TNT Primry nerobic reduction metbolite of TNT Bcteri fcilitted In vivo bioccumultion of A-DNT from TNT exposures Erthworms Slmnders Low wter solubility nd voltility Moderte mobility in soil Plnts - highest concentrtion in roots

3 Trnsformtion Pthwy O - O - O N + NHOH O N + NH2 O O - N + O N + O - N + O O - 2HA-DNT N + O O - 2-mino-4,6- dinitrotoluene (2A-DNT) N + O O - 2,4,6- Trintirotoluene (TNT) O O - N + O N + O - N + O - O O N + O - NHOH 4HA-DNT NH 2 4-mino-2,6- dinitrotoluene (4A-DNT)

4 Concentrtions of TNT nd primry brekdown products* Soil ug/g TNT 2A-DNT 4A-DNT Dry Initil Finl Worms ug/g TNT 2A-DNT 4A-DNT Initil Midpoint Finl *Johnson et l. 2

5 Soil concentrtions of TNT (prent) nd reduction products (Bzr et l. 28) 2A-DNT concentrtions 4 ug/g TNT concentrtions mg/kg 325 mg/kg 75 mg/kg 15 mg/kg 3 mg/kg ug/g Initil Midpoint Finl 4A-DNT concentrtions mg/kg 325 mg/kg 75 mg/kg 15 mg/kg 3 mg/kg Initil Midpoint Finl 5 ug/g mg/kg 325 mg/kg 75 mg/kg 15 mg/kg 3 mg/kg Initil Midpoint Finl

6 TNT trnsformtion A nitro group on the TNT ring is rpidly reduced to n mine (2A-DNT or 4A-DNT) In vivo nd in situ In situ it is concentrtion dependnt In vivo it occurs t exposure point TNT prent rrely found in tissue Rte limiting secondry metbolic step 2A-DNT or 4A-DNT most prevlent in tissue of nimls exposed to TNT Little plnt uptke of prent or metbolites

7 2A-DNT Effects Mmmls - Acute Only in Rts nd Mice (LD5 rts mg/kg; mice mg/kg). Centrl nervous system excitbility nd/or depression, exggerted reflexes, txi, delyed deths to 1d fter dosing, yellow-ornge urine; 5% bsorbed (Ellis et l. 198). Amphibins Slmnders Soil [2A-DNT] nd [4A-DNT] monitored with soil / erthworm TNT exposure - no dverse helth effects observed (Johnson et l. 2). Erthworms - Toxicity 4A-DNT > TNT > 2A-DNT. 2A-DNT bioccumulted most nd needs considertion when evluting overll TNT toxicity (Lchnce et l. 24). Birds - Northern Bobwhite (Colinus virgininus) Reptiles Western fence lizrd (Sceloporus occidentlis) Amphibins red-bcked slmnder (Plethodon cinereus)

8 Soil mphibin model Plethodon cinereus Lungless Thin integument Terrestril Long-lived Smll home rnge ( m2 (Petrnk 1998)

9 Slmnder Toxicity Test 28-d exposure Blood prmeters evluted Histopthologicl exmintion Biomrkers Soils spiked t 4 concentrtions + control Fed Drosophil Weighed weekly Fed every other dy Observed dily

10 A-DNT soil exposures to P. cinereus 1d rnge finding study 2A-DNT nd 4A-DNT 2A-DNT more toxic No mortlity to 1k mg/kg, but greter occurrence of overt symptoms. 28d subchronic 2A-DNT study <.5, 34, 173, 63, 1533 mg/kg (dry) No mortlity* Lethrgy, unresponsiveness, inppentnce, dverse behvior t mg/kg; dverse hemtology t 1533 mg/kg. *One deth t 63 mg/kg not thought to be compound relted (Bzr et l. in prep).

11 Sceloporus s Reptile Model > 7 species from northern U.S. to Pnm Se level to > 4 m, deserts to sublpine forests Terrestril hbitts vry geogrphiclly Size vries from 4 to 6gm (15-25g, 2 25cm totl length) Diurnl, hiberntes / estivtes Invertivore insects - beetles, flies, nts, spiders, snils

12 U.S. Rnge Mps Western & Estern Fence Lizrds (Sceloporus occidentlis / undultus) NtureServe. 28. NtureServe Explorer (http.//

13 Bsic Study Design Acute lethl (LD 5 ) Subcute (14-Dy) Subchronic (6-Dy)

14 Technicl Approch Acute LD 5 Sequentil stgewise probit nlysis (N=24) dose Stge 1 Stge 2 Stge 3 Sub-cute Rnge-finding (14d) study (N=32) Sub-chronic d study (N=12) 5-tretments (4 doses+1control) 12/sex/tretment

15 Acute Toxicity 6 Cumultive Mortlity (%) 4 2 Mles R 2 =.98 p <.1 Femles R 2 =.99 p <.1 Cumultive Animl Mortlity LD 5 - no sex difference Mles = 146 (947, 287) Femles = 1867 (176, 3237) Depression, wekness, norexi, weight loss, yellow vent nd feces 1 2A-DNT (mg/kg) 1 Percent dys survived decresed with incresing dosge - no sex difference. Averge (dys): Mles = 9.29 ± 1.1 Femles = 9.91 ±.99 Dys Survived (%) Mles R 2 =.39 p =.54 1 Femles R 2 =.79 p <.1 2A-DNT (mg/kg)

16 Subcute (14-Dy) Survivl (dys) b b Crickets b bc bc c bc A-DNT Dose (mg/kg-d) A-DNT Dose (mg/kg-d) Significnt effects on survivl t 95 mg/kg-d. Two highest groups survived pprox. 7 nd 6 dys BW loss (%) Loss of BW ws dose-relted in the lower exposures due to pproximte 14-d survivl times. 2A-DNT Dose (mg/kg-d)

17 Subchronic (6-Dy) Survivl (dys) N = 9 N = 1 b N = 4 N = Surviving to 6 dys c d N = 2 d N = N = A-DNT (mg/kg-d) Survivl time nd number of lizrds per group decresed significntly t 15 mg/kg-d in the 6-dy experiment.

18 Subchronic (6-Dy) 4 Crickets / dy b c d e Reduced feeding rtes were sttisticlly significnt t 15 mg/kg-d A-DNT Dose (mg/kg-d) 2 Net loss in BW t 15 mg/kg-dy, coincident with dily cricket intke of 2.5. Chnge in BW compred to Dy. BW chnge (%) b b b b A-DNT Dose (mg/kg-d)

19 Subchronic (6-Dy) 5 12 Hb (g/dl 8 4 Hct (%) WBC (13uL No significnt differences in mesured hemtologic endpoints. Totl Solids (g/d RBC (16/uL

20 Subchronic (6-Dy) 2A-DNT Dose (mg/kg-d) ALB (g/dl) 2.1 +/ / / ALKP (U/L) 34. +/ / / AST (U/L) / / / BUN (mg/dl) / / / Cretinine (mg/dl).53 +/ / / Phosphorus (mg/dl) / / / Uric Acid (mg/dl) / / / Vlues : Men ± SEM

21 Subchronic (6-Dy).6 Liver Kidney c Orgn Mss (g).4.2 b c bc bc No difference in liver mss. Kidney enlrged t 15 mg/kg-d A-DNT (mg/kg-d).16 c Splenic mss (g) b bc bc bc A-DNT (mg/kg-d)

22 Testes mss TNT Testes / Body Weight b b TNT (mg/kg*dy)

23 Sperm Production Mle Gmete N = 9 N = 1 N = 4 N = 2 Totl Motility Progression A-DNT (mg/kg-d) Non-significnt differences in totl numbers, motility, or progression of mle gmetes.

24 Summry S. occidentlis is useful lbortory model for toxicologicl investigtion in reptiles. Clinicl signs were non-specific nd best chrcterized by norexi, cchexi nd yellow-ornge discolored vent. Kidney effects; liver effects t levels where mortlity occurred. LOAEL / NOAEL were determined t 15 / 5 mg/kg-d (Bsed on survivl, body weight, food intke, kidney effects)

25 Northern Bobwhite Orl cute (stgewise probit) Orl subcute (14d rnge finding), 5, 125, 265, 55, 1 mg/kg-d Orl subchronic (6d gvge),.5, 3, 14, 3 mg/kd-d

26 Acute Study - results LD5 = 1167 mg/kg Fieller s 95%CI (356,1466) Delt 95% (942, 1445)

27 Sub-cute Study - methods Dily gvge, 14 d Tretment levels, 5, 125, 265, 55, 1 mg/kd-d Mesurements: mortlity body weights orgn weights gross observtions

28 Sub-cute Study - results 16 # dys survived A-DNT (mg/kg-d)

29 Sub-cute Study - results No significnt differences in body weights mong tretments. Significnt differences in liver nd spleen : brin weight rtios mong tretments for femles only. orgn brin hert liver kidneys spleen gonds tretment no no yes (f) no yes (f) no

30 Sub-cute Study - results Liver : Brin Weight Rtios,b b

31 Sub-cute Study - results Spleen : Brin Weight Rtios,c b,c b b

32 Sub-cute Study - results Consistent signs upon necropsy: enlrged gll bldder green food contents in gizzrd no food in lower GI, lthough crop full scnt white feces (urtes only)

33 Sub-chronic Study - results Significnt differences in feed consumption in both genders. No significnt differences in body weights mong tretments. Significnt differences in liver : brin weight rtios mong tretments for both genders. orgn brin hert liver kidneys spleen gonds tretment no no yes no no no

34 Sub-chronic Study - results Weekly Feed Consumption mle weekly feed consumption feed feed consumption consumed (g) *.5, 3, 14 mg/kg-d > & 3 mg/kg-d dys exposed

35 Sub-chronic Study - results Weekly Feed Consumption femle weekly feed consumption feed feed consumption consumed (g) lowest feed mg/kg-d dys exposed

36 Sub-chronic Study - results mle weekly body weights body weight (g) Weekly Body Weights femle weekly body weights dys exposed dys exposed body weight (g) dys dys exposed

37 Sub-chronic Study - results mle weekly body weights 25 body weight (g) Weekly Body Weights dys dys exposed exposed 3 25 femle weekly body weights body weight (g) dys exposed

38 Sub-chronic Study - results Liver / Brin Weight Indices,b b b b A,B A A,B A,B B

39 Sub-chronic Study - results Hemtology results: Effect? Hemoglobin no Hemtocrit no Totl solids no Erythrocytes no Leukocytes yes - femles only

40 Sub-chronic Study - results Totl leukocytes (WBC),b,b b

41 Sub-chronic Study - results Blood chemistry results: Alkline phosphtse Alnine minotrnsferse Asprtte minotrnsferse Clcium ion Cretine kinse Totl protein Globulin Albumin Lctte dehydrogense Phosphte Triglycerides Uric cid Sodium ion Potssium ion Chlorine ion Effect? no yes - mles only no no no no no no no no yes, mles only no no no no

42 Sub-chronic Study - results Alnine minotrnsferse (ALT),b b,b,b

43 Sub-chronic Study - results Triglycerides (TRIG),c b b,c,b

44 Summry subchronic LOAELs/NOAELs TNT A-DNT Trgets (TNT/ADNT) Amphibins Reptiles Birds Blood Behvior Blood Kidney Kidney/liver Liver

45 Summry ADNT is primry TNT metbolite Effects from ADNT exposure re different from TNT Differences between species ADNTs re less toxic from cute exposures thn TNT, however, ADNTs re more toxic thn TNT from subchronic exposures Different sequele, different endpoints

46 Acknowledgements Ptrici Bell Gund Reddy George Prker Ken Despin Terry Hnn Rebecc Kilby Bob Sunderlnd Development of Toxicity Dt for Munition Compounds to Support Toxicity Reference Vlue Derivtions for Wildlife. SERDP ER-142 The views expressed in this presenttion re those of the uthor nd do not reflect the officil policy or position of the Deprtment of the Army, the Deprtment of Defense, or the U.S. Government.