scholarly journals A HISTOCHEMICAL METHOD FOR THE DEMONSTRATION OF 20α-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN RAT OVARIES

1964 ◽  
Vol 12 (9) ◽  
pp. 670-673 ◽  
Author(s):  
KÁROLY BALOGH
Keyword(s):  
Enzyme Activity ◽  
Corpus Luteum ◽  
Dehydrogenase Activity ◽  
Present Method ◽  
Hydroxysteroid Dehydrogenase ◽  
Microscopic Level ◽  
Corpora Lutea ◽  
Endocrine Glands ◽  
Progesterone Metabolism ◽  
Rat Ovary

20α-Hydroxysteroid dehydrogenase activity was localized histochemically in the corpus luteum of the rat by using Nitro-BT as an indicator. Intensive enzyme activity was obseryed in the corpus luteum cells, especially during involution. The placenta and corpora lutea of pregnancy failed to reveal enzyme activity during the last week of gravidity. Other tissues, including endocrine glands, liver and kidneys were also negative. The Present method offers a possibility to identify the sites of progesterone metabolism in the rat ovary at the microscopic level.

CYCLISCHE SCHWANKUNGEN DER AKTIVITÄTEN VON HYDROXYSTEROID-DEHYDROGENASEN IM CORPUS LUTEUM DES RINDES

1972 ◽  
Vol 69 (2) ◽  
pp. 369-384
Author(s):  
H. Brandau ◽  
L. Brandau ◽  
G. Mutzke
Keyword(s):  
Enzyme Activity ◽  
Corpus Luteum ◽  
Enzyme Activities ◽  
Optical Method ◽  
Activity Patterns ◽  
Hydroxysteroid Dehydrogenase ◽  
Corpora Lutea ◽  
Bovine Corpus Luteum ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT In the bovine corpora lutea periodical activities of the Δ53β-, 3β-, 17β-and 20β-hydroxysteroid dehydrogenase (OHSDH) as well as activities of glyceraldehyde-3-phosphate- and glucose-6-phosphate dehydrogenase were measured quantitatively and the alterations throughout the different stages of the cycle were studied. After homogenization of the tissue and fractionate centrifugation the enzyme activities were determined by a standardized optical method. The activities of the Δ53β-, and 3β- and 17β-OHSDH increase slowly during the first 7 days of the cycle, the maximum is reached abruptly on the 12th to 13th day of the cycle. After a striking reduction the activities decline continually to the 19th to 21st day reaching the values detected at the beginning of the cycle. The 20β-OHSDH increases slowly to the maximum on the 15th day of the cycle. Activities of the 3α-OHSDH were obtained only inconsistently. The behaviour of the activities of G6PDH was nearly identical with that of the 3β-OHSDH, while the GAPDH shows only little fluctuations of its activities. The obtained enzyme activity patterns of the maturating and high functional corpus luteum correspond to the well-known data of the biosynthetic function of the bovine corpus luteum. The changes of the amounts of progesterone and 20β-progesterol agree with the course of the activities of the 3β- resp. 20β-OHSDH.

REDUCTIVE PATHWAYS OF PROGESTERONE METABOLISM IN THE RAT OVARY

1972 ◽  
Vol 69 (1) ◽  
pp. 141-152 ◽  
Author(s):  
A. Zmigrod ◽  
H. R. Lindner ◽  
S. A. Lamprecht
Keyword(s):  
Hydroxysteroid Dehydrogenase ◽  
Prolactin Secretion ◽  
Ovariectomized Rats ◽  
Corpora Lutea ◽  
Microsomal Preparation ◽  
Progesterone Metabolism ◽  
Rat Ovary ◽  
Reducing Activity ◽  
Pituitary Prolactin

ABSTRACT Progesterone underwent extensive reductive metabolism when incubated with a microsomal preparation from rat ovaries in the presence of NADPH. The major products formed were 3β-hydroxy-5α-pregnan-20-one, 5α-pregnane-3,20-dione and 5α-pregnane-3β,20α-diol. Newly formed corpora lutea of pregnancy were almost devoid of any microsomal A-ring reducing activity (5α-reductase and a 3β-hydroxysteroid dehydrogenase) and of soluble 20α-hydroxysteroid dehydrogenase. The behaviour of the A-ring reducing enzymes paralleled that of 20α-ol dehydrogenase in that their activity (i) was high during the oestrous cycle; (ii) declined between the third and seventh day of pregnancy; and (iii) increased sharply in corpora lutea of pregnancy when ergocornine – a drug blocking pituitary prolactin secretion – was given to the rats, yet remained low when prolactin and ergocornine were administered concurrently. However, the A-ring reducing activity did not show the sharp pre-partum rise exhibited by 20α-ol dehydrogenase, thus deviating from a pattern compatible with a co-ordinate control of the three enzymes involved in the metabolic inactivation of progesterone. Contrary to a report in the literature, 5α-pregnane-3,20-dione (20 mg/rat/day) was found to be ineffective when tested for pregnancy or deciduoma supporting activity in ovariectomized rats. The microsomal reductases, if indeed operative in vivo, may restrict the availability of progesterone as an oestrogen precursor.

EFFECTS OF OESTRADIOL ON STEROID DEHYDROGENASE ACTIVITIES IN RAT CORPORA LUTEA

1980 ◽  
Vol 84 (3) ◽  
pp. 391-395 ◽  
Author(s):  
R. G. RODWAY ◽  
I. ROTHCHILD
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Corpora Lutea ◽  
Pregnant Rat ◽  
Oestradiol Treatment ◽  
Rapid Induction ◽  
Progesterone Secretion ◽  
Luteal Tissue ◽  
Steroid Dehydrogenase

The activities of 20α-hydroxysteroid dehydrogenase and 3β-hydroxysteroid dehydrogenase in rat corpora lutea during the second half of pregnancy were measured. In luteal tissue of the intact pregnant rat, 20α-hydroxysteroid dehydrogenase activity was undetectable between days 12 and 18 of pregnancy but appeared slowly after hypophysectomy and hysterectomy on day 12. Treatment of the hypophysectomized and hysterectomized animal with oestradiol delayed this increase until day 17, at which time a rapid induction of this enzyme occurred. In the normal pregnant rat mean luteal 3β-hydroxysteriod dehydrogenase activity increased between days 12 and 18 (P <0·05, Student's t-test) but fell rapidly after hypophysectomy and hysterectomy on day 12. Oestradiol treatment prevented this fall in activity and enzyme activity was not distinguishable from that of the intact rat. Progesterone secretion correlated well with the activities of these two enzymes in the three conditions examined.

THE INFLUENCE OF HAEMOGLOBIN-S AND G6PD DEFICIENCY ON THE ACTIVITY OF THE 17β-HYDROXYSTEROID DEHYDROGENASE OF INTACT HUMAN ERYTHROCYTES

1974 ◽  
Vol 75 (4) ◽  
pp. 793-800
Author(s):  
A. O. Sogbesan ◽  
O. A. Dada ◽  
B. Kwaku Adadevoh
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Sex Steroids ◽  
G6pd Deficiency ◽  
Incubation Medium ◽  
Hydroxysteroid Dehydrogenase ◽  
G6pd Activity ◽  
Reverse Transformation ◽  
Oxidative Transformation ◽  
Haemoglobin S

ABSTRACT The 17β-hydroxysteroid dehydrogenase activity in intact erythrocytes of Nigerian patients, in particular with regard to haemoglobin genotypes and G6PD* activity was studied. The G6PD activity of the erythrocyte did not affect the oxidative transformation of testosterone to androstenedione and of oestradiol to oestrone. The reduction (reverse transformation) was inhibited in G6PD-deficient erythrocytes but this inhibition was offset by the addition of 0.025 m glucose to the incubation medium. The per cent oxidation transformation of testosterone was higher in Hb-AA than in Hb-SS erythrocytes. It is suggested that the differences may be a result of either lower enzyme activity in the Hb-SS erythrocytes or of differences in the uptake and possibly binding of sex steroids by intact Hb-SS and Hb-AA erythrocytes.

ALTERATION OF 3β-HYDROXYSTEROID DEHYDROGENASE ACTIVITY IN RAT OVARIES DURING THE OESTROUS CYCLE

1974 ◽  
Vol 60 (3) ◽  
pp. 441-443 ◽  
Author(s):  
A. M. GAWIENOWSKI ◽  
J. N. CLARK ◽  
C. N. SRINIVASAN
Keyword(s):  
Enzyme Activity ◽  
Dehydrogenase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Oestrous Cycle

SUMMARY The activity of 3β-hydroxysteroid dehydrogenase has been determined during various stages of the oestrous cycle in rats. The enzyme activity was high during pro-oestrus and oestrus but low during dioestrus I and II.

scholarly journals Participation of intraluteal progesterone and prostaglandin F2 alpha in LH-induced luteolysis in pregnant rat

1998 ◽  
Vol 156 (2) ◽  
pp. 253-259 ◽  
Author(s):  
CO Stocco ◽  
RP Deis
Keyword(s):  
Corpus Luteum ◽  
Dehydrogenase Activity ◽  
Subcutaneous Administration ◽  
Hydroxysteroid Dehydrogenase ◽  
Good Evidence ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Prostaglandin F2 Alpha

We examined the participation of the intraluteal levels of progesterone (P4) and prostaglandin F2 alpha (PGF2 alpha) in the induction of luteolysis by LH and its relationship with the induction of the 20 alpha-hydroxysteroid dehydrogenase activity (20 alpha-HSD). Subcutaneous administration of four doses of 10 microgram ovine LH (oLH) at 0800, 0900, 1000 and 1100 h on day 19 of pregnancy induced a decrease in the activity of the enzyme 3 beta-HSD 24 and 48 h after treatment and an increase in luteal 20 alpha-HSD activity 48 h after oLH treatment when compared with control rats. Intraluteal and serum P4 levels were lower than control values 24 and 48 h after oLH treatment, with a significant increase in luteal PGF2 alpha content and a decrease in corpus luteum (CL) weight 48 h after oLH treatment. Intrabursal ovarian (i.b.) treatment with an inhibitor of PG's biosynthesis (diclofenac) (70 microgram/ovary) or P4 (3 microgram/ovary) on day 20 of pregnancy, prevented the increase in 20 alpha-HSD activity observed 48 h after oLH treatment, without any effect on 3 beta-HSD activity. The i.b. administration of P4 prevented the increase in intraluteal PGF2 alpha content induced by oLH treatment and the increases in 20 alpha-HSD activity and intraluteal PGF2 alpha content observed in control animals on day 21 of pregnancy. The inhibition of PG biosynthesis also prevents the decrease in intraluteal and serum P4 level induced by oLH. These results provide good evidence of the important participation of intraluteal P4 and PGF2 alpha on the oLH-induced luteolysis in pregnant rats. We also found the P4 produced by the CL is involved, in part, in the regulation of luteal PG synthesis. Thus, the early decline in 3 beta-HSD activity and the consequent fall in intraluteal P4 content, may trigger the synthesis of PGs and thereafter the increase in luteal 20 alpha-HSD activity to establish luteolysis.

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