FEMINIZATION OF THE HEPATIC-MICROSOMAL CYTOCHROME-P-450 SYSTEM IN BROOK TROUT BY ESTRADIOL, TESTOSTERONE, AND PITUITARY FACTORS

被引:64
作者
PAJOR, AM
STEGEMAN, JJ
THOMAS, P
WOODIN, BR
机构
[1] WOODS HOLE OCEANOG INST, DEPT BIOL, WOODS HOLE, MA 02543 USA
[2] UNIV TEXAS, INST MARINE SCI, PORT ARANSAS, TX 77509 USA
来源
JOURNAL OF EXPERIMENTAL ZOOLOGY | 1990年 / 253卷 / 01期
关键词
D O I
10.1002/jez.1402530108
中图分类号
Q95 [动物学];
学科分类号
071002 ;
摘要
The effects of estradiol, testosterone, and pituitary extract on hepatic microsomal enzymes were studied in sham‐operated and gonadectomized immature brook trout. Estradiol reduced the specific content of cytochromes P‐450 and b5 by 70% or more in both groups. Testosterone and pituitary extract also decreased the levels of total P‐450 and b5, but to a lesser extent. These latter effects were not evident when the contents of P‐450 and b5 were normalized per g liver. Immunoblot analysis with antibodies to P‐450 forms from a teleost (scup) showed the presence of cross‐reacting proteins in control fish, presumed counterparts to the scup forms. Levels of a trout counterpart to P‐450A (a putative testosterone 6β‐hydroxylase) were strongly suppressed in estradiol‐treated fish. A trout P‐450B counterpart was suppressed in estradiol‐treated fish, but less strongly than was the P‐450A counterpart. The trout orthologue of hydrocarbon‐inducible P‐450E (P‐450IA1), the aryl hydrocarbon hydroxylase (AHH) catalyst, was undetectable in any group, consistent with very low levels of AHH activity in these fish. Estradiol or pituitary extract also decreased the levels of NADH‐cytochrome b5 and NADPH‐cytochrome P‐450 reductase activities in sham‐operated but not in gonadectomized fish. Gonadectomy alone also lowered the levels of reductase activities but not of total P‐450 or b5, suggesting an influence of gonads in maintaining normal levels of the reductases. The results support a prominent suppressive role for estrogens in producing the general sex differences in microsomal enzymes in fish liver and indicate that there could be affects on several P‐450 forms. However, the mechanism of hormone action in this regulation is uncertain. The results also suggest the existence of unidentified, possibly gonadal, factors which contribute to the regulation of reductases in teleost liver. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company
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页码:51 / 60
页数:10
相关论文
共 36 条
[1]   AGE-RELATED AND SEX-RELATED EXPRESSION OF YTOCHROMES-P450F AND P450G IN RAT-LIVER [J].
BANDIERA, S ;
RYAN, DE ;
LEVIN, W ;
THOMAS, PE .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1986, 248 (02) :658-676
[2]   INDUCTION OF ARYL-HYDROCARBON HYDROXYLASE-ACTIVITY IN EMBRYOS OF AN ESTUARINE FISH [J].
BINDER, RL ;
STEGEMAN, JJ .
BIOCHEMICAL PHARMACOLOGY, 1980, 29 (06) :949-951
[3]   IDENTIFICATION AND QUANTIFICATION OF STEROIDS IN THE SERUM OF RAINBOW-TROUT DURING SPERMIATION AND OOCYTE MATURATION [J].
CAMPBELL, CM ;
FOSTIER, A ;
JALABERT, B ;
TRUSCOTT, B .
JOURNAL OF ENDOCRINOLOGY, 1980, 85 (03) :371-378
[4]  
Colby H., 1980, ADV SEX HORMONE RES, V4, P27
[5]   STIMULATION OF PITUITARY GONADOTROPIN BY TESTOSTERONE IN JUVENILE RAINBOW-TROUT (SALMO-GAIRDNERI) [J].
CRIM, LW ;
EVANS, DM .
GENERAL AND COMPARATIVE ENDOCRINOLOGY, 1979, 37 (02) :192-196
[6]   ONSET OF GONADOTROPIC HORMONE ACCUMULATION IN THE IMMATURE TROUT PITUITARY-GLAND IN RESPONSE TO ESTROGEN OR AROMATIZABLE ANDROGEN STEROID-HORMONES [J].
CRIM, LW ;
PETER, RE ;
BILLARD, R .
GENERAL AND COMPARATIVE ENDOCRINOLOGY, 1981, 44 (03) :374-381
[7]   17-BETA-ESTRADIOL 2-HYDROXYLATION AND 4-HYDROXYLATION CATALYZED BY RAT HEPATIC CYTOCHROME-P-450 - ROLES OF INDIVIDUAL FORMS, INDUCTIVE EFFECTS, DEVELOPMENTAL PATTERNS, AND ALTERATIONS BY GONADECTOMY AND HORMONE REPLACEMENT [J].
DANNAN, GA ;
PORUBEK, DJ ;
NELSON, SD ;
WAXMAN, DJ ;
GUENGERICH, FP .
ENDOCRINOLOGY, 1986, 118 (05) :1952-1960
[8]   INDUCED CYTOCHROME-P-450 IN FUNDULUS-HETEROCLITUS ASSOCIATED WITH ENVIRONMENTAL CONTAMINATION BY POLYCHLORINATED-BIPHENYLS AND POLYNUCLEAR AROMATIC-HYDROCARBONS [J].
ELSKUS, AA ;
STEGEMAN, JJ .
MARINE ENVIRONMENTAL RESEARCH, 1989, 27 (01) :31-50
[9]  
ERNSTER L, 1974, DRUG METAB DISPOD, V1, P66
[10]  
GUSTAFSSON JA, 1980, BIOCHEM ACTION HORM, V7, P47