Orthotopic Liver Transplantation and the Cytosolic Estrogen Androgen Receptor Status of the Liver: The Influence of the Sex of the Donor

Transcription

1 /89/15 861$2./ HEPATOLOGY Copyright <t' 1989 y the Americn Assocition for the Study of Liver Diseses VoL 1. No. S, pp. R61-866, 198B Printed in US.A. Orthotopic Liver Trnsplnttion nd the Cytosolic Estrogen Androgen Receptor Sttus of the Liver: The Influence of the Sex of the Donor DELAWIR KAHN, QIHUA ZENG, LEONARD MAKOWKA, NORIKO MURASE, YASUAKI NAKAJIMA, PATRICIA K. EAGON, ANTONIO FRANCAVILLA, THOMAS E. STARZL AND DAVID H. VAN THIEL Deprtments of Surgery nd Medicine, The University of Pittsurgh School of Medicine, Pittsurgh, Pennsylvni Mmmlin liver is known to contin cytosolic receptors for oth estrogens nd ndrogens. Furthermore, certin mmmlin heptic functions re known to disply sexul dimorphism. However, in clinicl liver trnsplnttion, the sex of the donor is not tken into considertion in selection of the donor. In this study, the effect of liver trnsplnttion on the estrogen nd ndrogen receptor content of the liver ws determined. Adult mle nd femle rts were sujected to orthotopic liver trnsplnttion, using donors form oth the sme nd the opposite sex s the recipient. The nimls were killed on the tenth postopertive dy, nd the livers were ssyed to determine their cytosolic estrogen nd ndrogen receptor content. Trnsplnttion of liver from mle donor into mle recipient, from mle donor into femle recipient nd from femle donor into mle recipient produced similr chnges in the numer of cytosolic estrogen nd ndrogen receptors in heptic cytosol. In ll three situtions, the estrogen receptor content in the cytosol of the trnsplnted liver ws the sme s tht found in n unoperted mle liver, nd the cytosolic content of the ndrogen receptor ws the sme s tht of n unoperted femle liver. After trnsplnttion of the liver from femle donor into femle recipient, the estrogen nd ndrogen receptor content in the cytosol of the trnsplnted liver ws the sme s tht of n unoperted femle. A consistent finding in this study ws reduction in the cytosolic ndrogen receptor ctivity of the trnsplnted liver when mle ws either the recipient or donor. This reduction ws mximl t 1 dys posttrnsplnttion. At 4 dys following trnsplnttion, prtil recovery in the ndrogen receptor citivy of heptic cytosol hd occurred. These studies demonstrte tht orthotopic liver trnsplnttion chnges the cytosolic content of oth the estrogen nd ndrogen receptors of the liver, nd their rtios my hve importnt Received June 23, 1988; ccepted April 28, Supported y reserch grnts from the Veterns Administrtion (Project Grnt AM 29961), from the Ntionl Institute of Dietes nd Digestive nd Kidney Diseses (Grnt AM 32556) nd from the Ntionl Institute on Alcohol Ause nd Alcoholism (Grnt AA 661). Dr. D. Khn ws supported y grnt from the Medicl Reserch Council of South Afric. Address reprint requests to: Dvid H. Vn Thiel, M.D., lj Scife Hll, University of Pittsurgh School of Medicine, Pittsurgh, Pennsylvni effects during the immedite postopertive period nd profound long-term consequences reltive to gender differences in heptic function. Receptors for oth estrogens nd ndrogens hve een identified in the liver of oth rts nd mn, nd their properties hve een studied extensively (1-6). However, the precise function of these receptors remins unresolved. Nonetheless, in mmmls certin functions of the liver re known to disply sexul dimorphism (7-9). Testosterone present in utero nd fter puerty ppers to e the mjor determinnt of the difference etween the sexes in heptic function (8). In recent yers, orthotopic trnsplnttion of the liver hs ecome n estlished lterntive in the mngement of ptients with endstge liver disese (1, 11). Donors for liver trnsplnttion re currently selected with regrd only to the ABO lood group nd size comptiility with the recipient. The sex of the donor is not tken into considertion. In view of the sexul dimorphic chrcter of heptic function, the choice of prticulr donor sex my e importnt for the initil success of the trnsplnt procedure s well s susequent long-term norml function of the grft (12). In this study, the effect of orthotopic trnsplnttion on the estrogen nd ndrogen receptor content of the liver in mle nd femle rts, using donors from oth the sme nd the opposite sex s the recipient, ws determined. MATERIALS AND METHODS Animls nd Chemicls. Adult Lewis rts weighing 2 to 35 gm were purchsed from Hrln Sprgue-Dwley (Indinpolis, IN). Sodium molydte, diethylstilestrol, Tris se nd ovine serum lumin were purchsed from Sigm Chemicl Co. (St. Louis, MO). New Englnd Nucler (Boston, MA) provided the (3HJmethyitrienoione CH-RI88I; 85 Ci per mmole) nd unleled RI88l. Aqueous counting scintillnt ws otined from Amershm Corp. (Arlington Heights, IL). All other chemicls were otined from Fisher Scientific Co. (Pittsurgh, PAl. Surgicl Procedures. The nimls were llocted to five groups nd treted s follows: 24 mle rts (Group 1) were sujected to orthotopic liver trnsplnttion using livers from mle donors. At vrious times up to 8 weeks postopertively, groups of nimls were nesthetized with ether, nd their livers

2 862 KAHN ET AL. HEPATOLOGY were removed, weighed nd used to determine the level of the estrogen nd ndrogen receptor content in the cytosol of the trnsplnted liver. An dditionl five mle rts (Group 2) were sujected to orthotopic liver trnsplnttion using livers from mle donors nd, t 1 dys postopertively, the nimls were nesthetized with ether, nd the livers were removed, weighed nd used to determine the content of the estrogen nd ndrogen receptors in the cytosol of the trnsplnted liver. Five mle rts (Group 3) were sujected to orthotopic liver trnsplnttion using liver otined from femle donor. On the tenth postopertive dy, the recipient nimls were nesthetized with ether, nd the livers were removed, weighed nd used to determine the content of estrogen nd ndrogen receptors in the cytosol of the trnsplnted liver. Five femle rts (Group 4) were sujected to orthotopic liver trnsplnttion using livers from mle donors. On the tenth postopertive dy, the nimls were nesthetized with ether, nd the livers were removed, weighed nd used to determine the estrogen nd receptor content in the cytosol of the trnsplnted liver. Five femle rts (Group 5) were sujected to orthotopic liver trnsplnttion using orgns otined from femle donors. On the tenth postopertive dy, the nimls were nesthetized with ether, nd the trnsplnted livers were removed, weighed nd used to determine the estrogen nd ndrogen receptor content of the heptic cytosol. Orthotopic Liver Trnsplnttion. Orthotopic trnsplnttion of the liver in the rt ws performed using the cuff technique s descried y Kmd nd Cine (13) for the portl vein, suprheptic ven cv nd infr heptic ven cv. Preprtion of the Cytosol. The livers were homogenized in 4 volumes of ice-cold uffer consisting of.25 M sucrose, 1.5 mm EDTA, 1 mm mercptoethnol nd 1 mm Tris-HCl (ph 7.4) using Brinkmn Polytron homogenizer. The homogente ws centrifuged t 13, x g for 1 hr t 4 "C, nd the superntnt otined ws used for ll of the ssys performed. Estrogen Receptor Activity. The specific inding of sturting concentrtion of [3H)estrdiol ws used to determine the cytosolic estrogen receptor content (1). The heptic cytosol ws diluted 1:1 with uffer consisting of 4 mm sodium molydte, 1.5 mm EDTA nd 1 mm Tris-HCl (ph 7.4) in order to stilize the estrogen receptor. A mixture consisting of 2 f.li diluted cytosol, 25 f.ll 3 mm [3HJestrdioi nd 25 f.ll ethnol ws used to determine the totl inding [3HJestrdioL Nonspecific inding ws mesured in prllel ssys in which the ethnol ws replced with 25 f.ll 3 f.lm unleled diethylstilestrol dissolved in ethnol. In ech cse, the mixture ws llowed to incute for 2 hr t 4 "C, nd the rection ws terminted y the ddition of.4 ml 1 % dextrn-coted chrcol to remove unound steroid. After centrifuging t 1,5 x g for 5 min t 4 C, the superntnt ws trnsferred crefully to scintilltion vil contining 8 ml ACS scintilltion fluid. The rdioctivity in the superntnt ws mesured in Pckrd Tri-Cr 46 CD liquid scintilltion system (Downers Grove,IL). Androgen Receptor Activity. The ssy utilized to quntitte the cytosolic ndrogen receptor content ws similr to the one descried ove for the estrogen receptor with minor exceptions (2). Totl inding ws mesured using mixture of 2 III of the cytosol with 25 f.ll tritited RI881, synthetic ndrogen. Prllel ssys in which 25 III unleled Rl881 (3 f.lm) were dded to the mixture were used to determine the nonspecific inding. The inding of Rl881 to glucocorticoid receptors ws locked y dding 5 11M trimcinolone cetonide to the ssy mixture. After n overnight incution t 4 "C, the rection ws terminted y dding.41 ml 1 % dextrn-coted chrcol to remove unound RI881. The mixture ws centrifuged t 1,5 x g for 5 min t 4 "C, nd the superntnt ws plced in scintilltion vils with 8 ml ACS scintilltion fluid. The rdioctivity present in the superntnt ws counted in Pckrd Tri-Cr 46 CD liquid scintilltion system. Miscellneous Methods. The method of Lowry et l. (14) ws used to determine the cytosolic protein concentrtion using ovine serum lumin s the stndrd. All results re reported s men vlues ± S.E. Sttisticl nlysis of the dt ws performed using nlysis of vrince nd pproprite pired comprison tests. A p vlue of.5 or less ws considered to represent significnt difference. RESULTS The effect of orthotopic liver trnsplnttion, from mle donor to mle recipient, on the cytosolic estrogen receptor ctivity of the liver is shown in Figure 1. The cytosolic estrogen receptor content in the liver remined stle up to 2 dys fter the trnsplnt. A smll ut significnt reduction in the level of the estrogen receptor content ws oserved t 3 dys postopertively (p <.5). Therefter, the level of estrogen receptor content incresed stedily nd returned to preopertive sl mle levels y 5 dys fter trnsplnttion. The chnge in the cytosolic ndrogen receptor content in the heptic cytosol fter trnsplnttion of the liver from mle donor to mle recipient is shown in Figure l. The seline preopertive level of ndrogen receptor content in the heptic cytosol ws 3.45 ±.47 fmoles per mg protein. A significnt (p <.1) reduction in the level of the cytosolic ndrogen receptor content in the liver ws oserved t 1 dys fter trnsplnttion nd persisted for t lest 4 dys. At 4 dys, the ndrogen receptor content in the mle llogrft ws still significntly (p <.5) lower thn it ws preopertively, ut recovery towrd levels seen preopertively ws evident. The chnges in the cytosolic estrogen nd ndrogen receptor content of the liver t 1 dys fter trnsplnttion in the cse of liver otined from mle donor nd trnsplnted into mle recipient re shown in Figure 2. The level of the estrogen receptor content of the heptic cytosol ws unchnged compred to preopertive levels. In contrst, the level of the cytosolic ndrogen receptor content in the llogrft liver ws reduced significntly (p <.1) compred to the sl pretrnsplnt vlue. When the rtio of estrogen receptor content to ndrogen receptor content t 1 dys following orthotopic liver trnsplnttion is compred to tht of unoperted mle nimls, significnt increse is seen in the trnsplnted nimls (p <.1) (Fig. 2). The effects of trnsplnttion of liver otined from femle nd trnsplnted into mle recipient in terms of the estrogen nd ndrogen receptor content in heptic cytosol t 1 dys fter the trnsplnt re shown in Figure 3. The level of cytosolic estrogen receptor content in the liver fter trnsplnttion ws significntly (p <.1) less thn tht of norml femle liver ut ws similr to the level of estrogen receptor found in norml mle liver. In contrst, the level of the ndrogen receptor content in heptic cytosol otined from fe-

3 Vol. 1, No.5, 1989 HEPATIC SEX HORMONE S AND LIVER ATION 863 ~~ o I:l Eo<.~ p..~ rz:i U.. rz:il:i. ~..., Z e rz:i';;- '-' II)... ~ Eo< e {I)!::- rz:i ~~ l:l Eo<.~ Il. ",""' u..,""1:1. 5 ~ 4 t t ~... 3 :.. Z E ","- E - " :l 2 t e ~ Q z!::- < 1 c- o = DAY - lid! DAY FIG. 1. () Estrogen receptor content (fmoles per mg protein) in the cytosol of livers trnsplnted from mle donor to mle recipient (n = 4 to 6 nimls per group per time point). () Androgen receptor content (fmoles per mg protein) in the cytosol of livers trnsplnted from mle donor to mle recipient (n = 4 to 6 nimls per group per time point). mle liver trnsplnted into mle recipient ws the sme s tht of norml femle liver, eing significntly (p <.1) less thn tht of norml mle liver. The rtio of the estrogen to ndrogen receptor content in the trnsplnted liver ws significntly greter thn tht found in the unoperted mle liver ut significntly lower thn the vlue for n unoperted femle liver (oth p <.1) (Fig. 3). The levels of estrogen nd ndrogen receptor content in the heptic cytosol fter trnsplnttion of liver otined from mle donor into femle recipient re shown in Figure 4. The estrogen receptor content of the liver t 1 dys fter the trnsplnt ws significntly (p <.1) less thn tht found in norml intct femle liver ut ws similr to the level present in norml intct mle liver. However, the ndrogen receptor content of the liver fter trnsplnttion ws reduced to level found in norml intct femle liver (p <.1). The rtio of the estrogen receptor content to the ndrogen receptor content in the heptic cytosol in this group of nimls ws significntly lower thn tht present in the unoperted femle liver ut significntly greter thn ~~ ~.~ Il.... [ZlO u" «1"'- ~..., zel «1"- "Ol O~ r:>::o!n. «1~ " , ~ 24 '- 21 ~ ~ IB r 15 C- 12 ~ " 9-6 L c 3 r o L - ANDROGEN - = NORMAL ~ POST TRANSPLA~T f7j NORMAL FIG. 2. () Estrogen nd ndrogen receptor content (fmoles per mg protein) in the cytosol of the unoperted mle liver nd t 1 dys fter trnsplnttion of livers from mle donors into mle recipients (n = 5 nimls per group). () Rtio of the estrogen to ndrogen receptor content in the cytosol of unoperted mle nd femle livers nd livers trnsplnted from mle donors to mle recipients (n = 5 nimls per group). the vlue otined for un operted mle liver (oth p <.1) (Fig. 4). The estrogen nd ndrogen receptor content present in the heptic cytosol fter trnsplnttion of the liver from femle donor to femle recipient is shown in Figure 5. The levels of oth the estrogen nd ndrogen receptor content nd their rtio in heptic cytosol fter the trnsplnt were similr to those of norml intct femle liver t ll times studied from time of trnsplnttion through 4 dys following trnsplnttion. The estrogen to ndrogen receptor content rtio in the cytosol of the trnsplnted liver ws similr to the rtio found in the un operted femle liver t ll times studied ut ws significntly greter thn tht found in the unoperted mle liver (oth p <.1) (Fig. 5). DISCUSSION In this study, the estrogen receptor content present in the heptic cytosol, except for slight decrese seen t

4 864 KAHN ET AL. HEPATOLOGY - -NORMAL - I - NORMAL = POST TRANSPLA.I\'T POST NORMAL NORMAL ANDROGEN o ~'1DROGEN 27 t 24~ 21 ~ 16 ~ 15 ~ 12 ~ [ 3 L- o L - :--;ORMAL ~ POST o NORMAL FIG. 3. () Estrogen nd ndrogen receptor content (fmoles per mg protein) in the cytosol of the unoperted mle nd femle liver nd t 1 dys fter trnsplnttion of livers from femle donors into mle recipients (n = 5 nimls per group). () Rtio of the estrogen to ndrogen receptor content in the cytosol of unoperted mle nd femle livers nd livers trnsplnted from femle donors to mle recipients (n = 5 nimls per group) o - :--;ORMAL ~ POST TRA"SPLANT I NORMAL FIG. 4. () Estrogen nd ndrogen receptor content (fmoles per mg protein) in the cytosol of the unoperted mle nd femle liver nd t 1 dys fter trnsplnttion of livers from mle donors into femle recipients (n = 5 nimls per group). () Rtio of the estrogen to ndrogen receptor content in the cytosol of un operted mle nd femle livers nd livers trnsplnted from mle donors to femle recipients (n = 5 nimls per group). 3 dys posttrnsplnt, remined stle up to 5 dys fter orthotopic trnsplnttion of mle donor liver to mle recipient (Fig. l). In contrst, the cytosolic content of the ndrogen receptor ws significntly lower t 1 dys fter trnsplnttion of mle liver into mle recipient compred to preopertive levels (Fig. 1). Therefter, however, the ndrogen receptor content incresed with time in the new host ut still ws reduced, compred to either preopertive or intct mle levels t 4 dys fter the trnsplnt procedure. Trnsplnttion of liver otined from mle or femle donor into mle or femle recipient produced quite different chnges in the cytosolic estrogen nd ndrogen receptor content nd their reltive density in the trnsplnted liver. Only the trnsplnttion of femle donor liver into femle recipient produced results similr to those present in unoperted control nimls of the sme sex. Trnsplnttion of mle liver into mle recipient resulted in the estrogen receptor content eing the sme s tht present in norml mle efore surgery, ut the ndrogen receptor density declined to levels found in norml femle liver (Fig. 2). The chnges in the estrogen nd ndrogen receptor content of heptic cytosol fter trnsplnttion of liver otined from mle donor trnsplnted into femle recipient nd otined from femle donor ut trnsplnted into mle recipient were similr. In oth situtions, the estrogen receptor density of the cytosol ws the sme s in norml intct mle liver, nd the heptic ndrogen receptor density ws the sme s tht found in norml intct femle. In other words, fter trnsplnttion of femle liver into femle recipient, the liver, with regrd to the estrogen nd ndrogen receptor content of heptic cytosol, remins effectively identicl to tht of femle liver. In contrst, fter trnsplnttion of mle or femle liver into recipient of the opposite

5 .. ~_.. _.c_.~= ==='_= ==_==========_=_=.. =. = ==..._= =_ =======------::==== Vol. 1, No.5, 1989 HEPATIC SEX HORMONE S AND LIVER ATION 865,,--.9 o E-<~ c:.... IiIlO u'" IiIlI:lo "log zs 1iIl... ~.. o~ 1,. " ti.e 1iIl_ 1 d o - ANDROGEN,, = t:] IiIlO U'" IiIlI:lo 2 " log - zs 1iIl... ~.. o~,,- QO 1 Z S <!::. = POST -NORMAL NORMAL I8llllI POST : EZJ NORMAL FIG. 5. () Estrogen nd ndrogen receptor content (fmoles per mg protein) in the cytosol of the unoperted femle liver nd t 1 dys fter trnsplnttion of livers from femle donors into femle recipients (n = 5 nimls per group). () Rtio of the estrogen to ndrogen receptor content in the cytosol of unoperted mle nd femle livers nd livers trnsplnted from femle donors to femle recipients (n = 5 nimls per group). sex, the liver ssumes mle identity with regrd to its cytosolic estrogen receptor content nd femle identity with regrd to its cytosolic ndrogen receptor content. The findings reported herein my hve importnt implictions. Becuse the liver is known to disply sexul dimorphism with regrd to severl importnt functions, these chnges in the cytosolic estrogen nd ndrogen receptor content of the liver fter trnsplnttion my e importnt oth for the initil success of the trnsplnt procedure nd possily lso the long-term performnce of the liver in the recipient. A "feminiztion" of the liver of mle rts hs een reported to occur in ssocition with regenertion nd includes n increse in the serum level of estrdiol nd the heptic content of the estrogen receptor. These chnges occur while reduction in the serum level of testosterone nd the content of the ndrogen receptor within the liver is occurring (2, 6). Moreover, trnsloction of the estrogen receptor from the cytosolic comprtment of the cell to the nucler comprtment is seen prior to the initition of DNA synthesis. These chnges suggest n importnt role for nucler estrogen nd prticulrly tht n estrogen-dna interction exists prior to the initition of the regenertive process within liver (15). Thus, the chnges in the estrogen nd ndrogen receptor content seen in the trnsplnted livers reported herein my represent regenertive response to some trnsplnttion-relted heptic injury. Such regenertive response in trnsplnted orgn my e crucil for the successful engrftment of the liver fter trnsplnttion. During liver trnsplnttion, the liver grft is injured in numer of different wys, which includes n ischemic injury relted to the procurement process nd the preservtion time, n immunologicl injury occurring s consequence of the ttck mounted y the recipient's immune response, injury occurring s result of n infection relted to the trnsplnt experience nd, finlly, injury occurring s result of the toxicity of certin drugs, prticulrly cyclosporine, which re used to prevent grft rejection. Occsionlly, ecuse of mismtch etween the size of the donor nd the recipient, smll liver is trnsplnted into lrger recipient, nd heptic regenertion of such grfts is required for the grft to meet the metolic needs of the recipient (16, 17). Similrly, ecuse of the lck of suitle-sized peditric donors, some centers use prtilly heptectomized (reduced) dult livers in peditric recipients (18, 19). Both of these situtions require regenertive response on the prt of the trnsplnted orgn, nd norml regenertive response in these prticulr situtions my e crucil for the ultimte success of the trnsplnt procedure. Becuse estrogens nd their receptors re thought to ply n importnt role in the process of heptic regenertion, the chnges oserved in the estrogen nd ndrogen receptor levels in heptic cytosol herein reported fter trnsplnttion my influence the regenertive response of such liver grfts. In the experiments performed, ecuse n inred strin of rts ws utilized nd cyclosporine ws not, nd the ischemi time of the trnsplnted liver ws short, these vriles were either not present or minimlly importnt. In clinicl trnsplnt sitution, ech of these vriles is present nd would only further enhnce the need for regenertive response. Cyclosporine, the immunosuppressive gent used routinely in most orgn trnsplnt progrms, hs severl untowrd effects including hirsutism, incresed lnugo hir growth, norml uterine leeding, firodenoms of the rest, virilism in femles nd tendency to develop dietes, ll of which pper to e medited, t lest in prt, hormonlly. Cyclosporine hs een shown to potentite heptic regenertion (2, 21), ut lso to increse the estrogen receptor content present within heptic cytosol (22). Thus, n interction etween the effects of cyclosporine on the estrogen receptor content in heptic cytosol nd the chnges oserved in heptic cytosol fter trnsplnttion herein reported my e synergistic nd hve importnt implictions.

6 866 KAHN ET AL. HEPATOLOGY REFERENCES 1. Egon PK, Fisher SE, Imhoff AF, et l. Estrogen-inding proteins of mle rt liver: influences of hormonl chnges. Arch Biochem Biophys 198; 21: Frncvill A, Egon PK, DiLeo A, et l. Sex hormone relted functions in regenerting mle rt liver. Gstroenterology 1986; 91: Bnnister P, Sheridn P, Losowsky MJ. Identifiction nd chrcteriztion of the humn ndrogen receptor. Clin Endocrinol1985; 23: Aten RF, Dickson EB, Eisenfeld AJ. Estrogen receptor in dult mle rt liver. Endocrinology 1978; 13: Eisenfeld AJ, Aten R, Weinerger MJ, et l. Estrogen receptor in mmmlin liver. Science 1976; 191: Egon PK, Porter LE, Frncvill A, et l. Estrogen nd ndrogen receptors in the liver: their role in liver disese nd regenertion. Semin Liver Dis 1985; 5: Roy AK, Chtterjee B. Sexul dimorphism in the liver. Annu Rev Physiol 1983; 45: Brdin CW, Ctterl JS. Testosterone: mjor determinnt of extrgenitl sexul dimorphism. Science 1981; 211: Gustfsson JA, Mode A, Norstedt G, et l. Sex steroid induced chnges in heptic enzymes. Annu Rev Physiol1983; 45: Strzl TE, Iwtsuki S, Vn Thiel DH, et l. Evolution of liver trnsplnttion. Heptology 1982; 2: Iwtsuki S, Strzl TE, Todo S, et l. Experience in 1, liver trnsplnts under cyc1osporine-steroid therpy: survivl report. Trnsplnt Proc 1988; 2: Khn D, Mkowk L, Gvler JS, et l. The outcome fter clinicl liver trnsplnttion is influenced y the gender of the donor. Gstroenterology (in press). 13. Kmd N, Cine RY. Orthotopic liver trnsplnttion in the rt: technique using cuff for portl vein nstomosis nd iliry dringe. Trnsplnttion 1979; 28: Lowry OH, Roserough NJ, Frr AL, et l. Protein mesurement with the Folin phenol regent. J BioI Chern 1951; 193: Frncvill A, DiLeo A, Egon PK, et l. Regenerting rt liver: correltion etween estrogen receptor locliztion nd deoxyrionucleic cid synthesis. Gstroenterology 1984; 86: Vn Thiel DH, Gvler JS, Km I, et l. Rpid growth of n intct humn liver trnsplnt into recipient lrger thn the donor. Gstroenterology 1987; 93: Km I, Lynch S, Svns G, et l. Evidence tht host size determines liver size: studies in dogs receiving orthotopic liver trnsplnts. Heptology 1987; 7: Bismuth H, Houssin D. Reduced-sized orthotopic liver grft in heptic trnsplnttion in children. Surgery 1984; 95: de Hemptinne B, Slizonni M, Tn KC, et l. The technique of liver size reduction in orthotopic liver trnsplnttion. Trnsplnt Proc 1988; 2(Suppl. 1): _ Kim YI, CIne RY, Ngsue N. Cyc1osporin A stimultes prolifertion of the liver cells fter prtil heptectomy in rts. Surg Gynecol Ostet 1988; 166: Khn D, Mkowk L, Li H, et l. Cyc1osporine ugments the heptic regenertive response in rts. Dig Dis Sci (in press). 22. Khn D, Gvler JS, Li H, et l. Effect of cyclosporine on heptic estrogen nd ndrogen receptor levels efore nd fter prtil heptectomy. Dig Dis Sci (in press). r! C