The application of continuous monitoring microdensitometry to an analysis of NAD+ binding and 3β-hydroxy-Δ5-steroid dehydrogenase activity in the regressing corpus luteum of the pro-oestrous rat ovary

1986 ◽  
Vol 18 (1) ◽  
pp. 41-44 ◽  
Author(s):  
M. Gordon ◽  
W. R. Robertson
1964 ◽  
Vol 12 (9) ◽  
pp. 670-673 ◽  
Author(s):  
KÁROLY BALOGH

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.


1984 ◽  
Vol 101 (3) ◽  
pp. 285-288
Author(s):  
F. Miyauchi ◽  
H. Kato ◽  
H. Yamashita ◽  
K. Ueda ◽  
H. Tamura ◽  
...  

ABSTRACT The effects of a conceptus-derived substance on the activity of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 20α-HSD in the ovary were studied in the rat. On day 7 of pregnancy (day 1 = insemination), rats were laparotomized and the desired number of conceptuses was aspirated from the uterus; thus, rats carrying one, two, three, four, five to seven or eight to ten conceptuses were prepared. They were autopsied on day 15 and 3β-HSD and 20α-HSD activity in the corpus luteum (CL) or non-luteal ovarian tissue (NLO) was determined. Conceptus number was directly related to 3β-HSD and inversely related to 20α-HSD activity in the CL. The serum progesterone level and CL weight were also directly related to conceptus number. Neither 3β-HSD nor 20α-HSD activity in the NLO was affected by conceptus number. These results indicated that 3β-HSD and 20α-HSD in the CL are probably regulated by placental hormone secreted in proportion to the number of conceptuses; in the NLO these enzymes may be controlled by a different mechanism. J. Endocr. (1984) 101, 285–288


1985 ◽  
Vol 106 (3) ◽  
pp. 269-273 ◽  
Author(s):  
D. G. Armstrong

ABSTRACT The object of this study was to examine changes in the activity of granulosa 3β-hydroxy-Δ5-steroid dehydrogenase during the ovulatory cycle of the domestic fowl. The enzyme activity in granulosa tissue from the largest follicle increased significantly during the period 8–14 h before an expected ovulation. The increase in activity occurs before the preovulatory surge of LH and near the time of lights off. During the 4–8 h period before an ovulation, i.e. the time of maximal plasma LH concentrations, 3β-hydroxy-Δ5-steroid dehydrogenase activity decreased in granulosa tissue from the largest follicle. This observation is explained by proposing that the enzyme is inhibited by the large amounts of progesterone found in the tissue at this time. The results indicate that important biochemical changes are taking place within granulosa tissue of the largest ovarian follicle before the preovulatory LH surge. J. Endocr. (1985) 106, 269–273


1998 ◽  
Vol 158 (2) ◽  
pp. 221-228 ◽  
Author(s):  
P Bagavandoss

The distribution of gelatinases/matrix metalloproteinases-2 and -9 (MMP-2 and MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in neonatal and gonadotropin-primed immature rat ovaries was studied by immunofluorescent microscopy. Immature female Long-Evans rats were primed with 15 IU pregnant mare's serum gonadotropin (PMSG) in 100 microliters PBS. Two days later, to induce ovulation, the rats were injected with human chorionic gonadotropin (hCG, 5 IU/100 microliters PBS). The animals were killed at appropriate times and the ovaries removed and processed for cryostat or paraffin sectioning. Ovaries were also obtained from 7-day-old neonatal rats and processed as above. In the neonatal rat ovary, MMP-2 was present in the follicle and in the ovarian surface epithelium. MMP-9 was not detectable in the neonatal ovary. TIMP-1 was present in the oocyte and in the surface epithelium. In the PMSG-primed ovary, MMP-2 was present in the granulosa and thecal cells of the ovary. MMP-9 distribution, however, was restricted to the interstitial and thecal cells. TIMP-1 was mainly present in the blood vessels and thecal cells, with minor staining in the granulosa cells. In the developing corpus luteum, luteal and endothelial cells were positive for MMP-2. MMP-9 localization was restricted to the plasma membrane of the luteal and interstitial cells. TIMP-1 was clearly observed in the luteal capillaries and, to a lesser extent, in the luteal cell plasma membrane. This distribution of MMP-2, MMP-9, and TIMP-1 in the corpus luteum persisted throughout the life span of the corpus luteum. The spatial and temporal distribution of the gelatinases and TIMP-1 suggests unique roles for these proteins in the rat ovary.


1998 ◽  
Vol 156 (2) ◽  
pp. 253-259 ◽  
Author(s):  
CO Stocco ◽  
RP Deis

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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