scholarly journals Effects of sex hormones on enzymic esterification of 2-(N-hydroxyacetamido)-fluorene by rat liver cytosol

1970 ◽  
Vol 120 (2) ◽  
pp. 409-416 ◽  
Author(s):  
Prabhakar D. Lotlikar
Keyword(s):  
Rat Liver ◽  
Adult Male ◽  
Male Rat ◽  
Female Rat ◽  
Liver Cytosol ◽  
Adult Male Rat ◽  
Derivatives Of ◽  
Sex And Age Differences ◽  
Rat Liver Cytosol

1. Enzymic esterifications of 2-(N-hydroxyacetamido)fluorene and several other hydroxamic acids by liver cytosol were studied. Determination of 2-acetamido-3-methylthiofluorene was used for the assay. 2. With rat liver cytosol, requirement for ATP, Mg2+ and SO42− suggested formation of phosphate and sulphate esters of 2-(N-hydroxyacetamido)fluorene. 3. Rats showed sex and age differences in their activity. Liver from adult male rat was at least twice as active as liver from adult female rat. No such sex differences were found in mice, hamsters and guinea pigs. 4. Administration of testosterone (300μg/day) subcutaneously for 8 days increased the activity in the female rat by 100%, whereas diethylstilboestrol (100μg/day) had no effect. In the male rat diethylstilboestrol treatment decreased the activity by 60%, whereas testosterone pretreatment was without any effect. 5. Among various endocrine ablations such as adrenalectomy, castration, adrenalectomy–castration and hypophysectomy in the adult male rat, hypophysectomy was found to be the most effective in decreasing the activity of the liver to about 50% of control values. 6. Like 2-(N-hydroxyacetamido)fluorene, various other N-hydroxy derivatives of 2-acetamido-7-fluorofluorene, 2-acetamidophenanthrene, 4-acetamidobiphenyl and 4-acetamidostilbene were also shown to be esterified to different extents by rat liver cytosol.

THE EFFECT OF MIROESTROL ON VAGINAL CORNIFICATION, PITUITARY FUNCTION AND PREGNANCY IN THE RAT

1961 ◽  
Vol 22 (3) ◽  
pp. 293-302 ◽  
Author(s):  
H. E. H. JONES ◽  
H. B. WAYNFORTH ◽  
G. S. POPE
Keyword(s):  
Oral Administration ◽  
Adult Male ◽  
Vaginal Epithelium ◽  
Pituitary Function ◽  
Ovariectomized Rat ◽  
Male Rat ◽  
Female Rat ◽  
Adult Male Rat ◽  
Mated Female

SUMMARY 1. The effectiveness of miroestrol in causing cornification of the vagina of the ovariectomized rat, inhibiting pituitary activity of the adult male rat and preventing pregnancy in the mated female rat has been compared with that of hexoestrol and stilboestrol when each oestrogen is administered either subcutaneously or orally. 2. Inhibition of pituitary function and prevention of pregnancy by these substances are directly related to their activity in producing cornification of the vaginal epithelium. Only large doses of oestrogen produce the first two responses fully. 3. When administered subcutaneously miroestrol has about 0·3 of the potency of stilboestrol and 0·25 of that of hexoestrol in each response studied. By oral administration it is 0·8 as potent as stilboestrol and more potent than hexoestrol. Since the potency of miroestrol compared with a given oestrogen administered in the same way is of the same order in each response, it is concluded that these substances are only capable of inhibiting the function of the pituitary and of preventing pregnancy because of their oestrogenic activity.

Estrogen Receptor in Adult Male Rat Liver*

Endocrinology ◽  
1978 ◽  
Vol 103 (5) ◽  
pp. 1629-1635 ◽  
Author(s):  
RAYMOND F. ATEN ◽  
ROBERT B. DICKSON ◽  
ARNOLD J. EISENFELD
Keyword(s):  
Estrogen Receptor ◽  
Rat Liver ◽  
Adult Male ◽  
Male Rat ◽  
Adult Male Rat

scholarly journals Metabolism of a glutathione conjugate of 2-hydroxyoestradiol-17β in the adult male rat

1972 ◽  
Vol 126 (5) ◽  
pp. 1067-1071 ◽  
Author(s):  
John S. Elce
Keyword(s):  
Bile Duct ◽  
Adult Male ◽  
Analytical Techniques ◽  
Male Rats ◽  
Male Rat ◽  
Glutathione Conjugate ◽  
Before And After ◽  
Adult Male Rat ◽  
Derivatives Of

Adult male rats with cannulated or ligated bile ducts were given S-(2-hydroxyoestradiol-1-yl)[35S]glutathione, S-(2-hydroxy[6,7-3H2]oestradiol-1-yl)glutathione or S-(2-hydroxyoestradiol-1-yl)[glycine-3H]glutathione by intraperitoneal injection. The recovery of radioactivity in the bile of bile duct-cannulated rats was 33–86% and in the urine of bile duct-ligated rats was 54–105%. Oestrogen thioether derivatives of glutathione, cysteinylglycine, cysteine and N-acetylcysteine were isolated from bile; only the N-acetylcysteine derivatives could be identified in the urine. The steroid moiety was characterized by microchemical tests before and after treatment with Raney nickel: 2-hydroxyoestradiol-17β was released from the glutathione conjugate, and 2-hydroxyoestrone and 2-hydroxyoestrone 3-methyl ether from the other conjugates. From intact rats the recovery of administered radioactivity was about 15% in the urine and 5% in the faeces over a period of several days and the radioactivity appeared to be largely protein-bound. The results demonstrate that injected oestrogen–glutathione conjugate undergoes conversion into N-acetylcysteine derivatives in vivo. Oestrogen–glutathione conjugates formed in the intact rat may be excreted in an apparently non-steroidal, possibly protein-bound form, which would not be detected by current analytical techniques.

scholarly journals Self-augmentation Effect of Male-specific Products on Sexually Differentiated Progesterone Metabolism in Adult Male Rat Liver Microsomes

2000 ◽  
Vol 276 (7) ◽  
pp. 4604-4610 ◽  
Author(s):  
Akihiko Yamada ◽  
Morio Yamada ◽  
Yukihisa Fujita ◽  
Takashi Nishigami ◽  
Keiji Nakasho ◽  
...  
Keyword(s):  
Rat Liver ◽  
Adult Male ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Progesterone Metabolism ◽  
Adult Male Rat ◽  
Male Specific

scholarly journals Participation of two structurally related enzymes in rat hepatic microsomal androstenedione 7α-hydroxylation

1990 ◽  
Vol 265 (1) ◽  
pp. 187-194 ◽  
Author(s):  
D J Waxman ◽  
D P Lapenson ◽  
K Nagata ◽  
H D Conlon
Keyword(s):  
Rat Liver ◽  
Adult Female ◽  
Adult Male ◽  
Liver Microsomes ◽  
High Specificity ◽  
High Rate ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Female Rat ◽  
Hydroxylase Activity

Rat hepatic cytochrome P-450 form 3 (testosterone 7 alpha-hydroxylase; P-450 gene IIA1) and P-450 form RLM2 (testosterone 15 alpha-hydroxylase; P-450 gene IIA2) are 88% identical in primary structure, yet they hydroxylate testosterone with distinct and apparently unrelated regioselectivities. In this study, androstenedione and progesterone were used to assess the regioselectivity and stereospecificity of these two P-450 enzymes towards other steroid substrates. Although P-450 RLM2 exhibited low 7 alpha-hydroxylase activity with testosterone or progesterone as substrate (turnover number less than or equal to 1-2 nmol of metabolite/min per nmol of P-450), it did catalyse androstenedione 7 alpha-hydroxylation at a high rate (21 min-1) which exceeded that of P-450 3 (7 min-1). However, whereas P-450 3 exhibited a high specificity for hydroxylation of these steroids at the 7 alpha position (95-97% of total activity), P-450 RLM2 actively metabolized these compounds at four or more major sites including the nearby C-15 position, which dominated in the case of testosterone and progesterone. The observation that androstenedione is actively 7 alpha-hydroxylated by purified P-450 RLM2 suggested that this P-450 enzyme might make significant contributions to microsomal androstenedione 7 alpha-hydroxylation, an activity that was previously reported to be associated with immunoreactive P-450 3. Antibody inhibition experiments were therefore carried out in liver microsomes using polyclonal anti-(P-450 3) antibodies which cross-react with P-450 RLM2, and using a monoclonal antibody that is reactive with and inhibitory towards P-450 3 but not P-450 RLM2. P-450 3 was thus shown to catalyse only around 35% of the total androstenedione 7 alpha-hydroxylase activity in uninduced adult male rat liver microsomes, with the balance attributed to P-450 RLM2. The P-450-3-dependent 7 alpha-hydroxylase activity was increased to approximately 65% of the total in phenobarbital-induced adult male microsomes, and to greater than 90% of the total in untreated adult female rat liver microsomes. These observations are consistent with the inducibility of P-450 3 by phenobarbital and with the absence of P-450 RLM2 from adult female rat liver respectively. These findings establish that P-450 RLM2 and P-450 3 can both contribute significantly to microsomal androstenedione 7 alpha-hydroxylation, thus demonstrating that the 7 alpha-hydroxylation of this androgen does not serve as a specific catalytic monitor for microsomal P-450 3.

scholarly journals Progesterone-binding site of adult male rat liver microsomes.

1990 ◽  
Vol 265 (19) ◽  
pp. 11035-11043
Author(s):  
M Yamada ◽  
K Indo ◽  
T Nishigami ◽  
K Nakasho ◽  
H Miyaji
Keyword(s):  
Binding Site ◽  
Rat Liver ◽  
Adult Male ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Adult Male Rat

Relationship between Sigma-like site and progesterone-binding site of adult male rat liver microsomes

Hepatology ◽  
1994 ◽  
Vol 20 (5) ◽  
pp. 1271-1280 ◽  
Author(s):  
Morio Yamada ◽  
Takashi Nishigami ◽  
Keiji Nakasho ◽  
Yukiyasu Nishimoto ◽  
Hideki Miyaji
Keyword(s):  
Binding Site ◽  
Rat Liver ◽  
Adult Male ◽  
Liver Microsomes ◽  
Male Rat ◽  
Rat Liver Microsomes ◽  
Adult Male Rat

scholarly journals Accurate determination of tissue steroid hormones, precursors and conjugates in adult male rat

2012 ◽  
Vol 153 (1) ◽  
pp. 63-71 ◽  
Author(s):  
Naoyuki Maeda ◽  
Emi Tanaka ◽  
Tomokazu Suzuki ◽  
Kanako Okumura ◽  
Sachiko Nomura ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Adult Male ◽  
Accurate Determination ◽  
Male Rat ◽  
Adult Male Rat
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