scholarly journals Studies on rat ovarian receptors for lutropin (luteinizing hormone). Factors influencing binding and response

1976 ◽  
Vol 160 (3) ◽  
pp. 607-613 ◽  
Author(s):  
K Muralidhar ◽  
N R Moudgal
Keyword(s):  
Luteinizing Hormone ◽  
Ovarian Response ◽  
Corpora Lutea ◽  
Human Choriogonadotropin ◽  
Factors Influencing ◽  
Pregnant Mare Serum Gonadotropin ◽  
Immature Rats ◽  
Lutropin Receptor ◽  
Serum Gonadotropin

The interaction of rat ovarian receptors with lutropin (luteinizing hormone, LH) in vitro was rapid and reversible. The degree of binding was saturable and susceptible to changes in the concentration of lutropin in the medium. The concentration of lutropin receptors in the ovary increases during the natural pubertal period and also in immature rats given pregnant-mare-serum gonadotropin and human choriogonadotropin. In the latter case, the increase in lutropin receptor, after injection of pregnant-mare-serum gonadotropin alone, could be detected only if the ovaries are freed of the bound gonadotropin before exposure to lutropin. The concentration of lutropin receptors was higher in the luteal compartment of the ovary than in the non-luteal parts and increased slightly in aged corpora lutea. Correlation between binding of lutropin to the ovary and the ovarian response to lutropin in terms of cyclic AMP production was found only in prepubertal rat ovaries and in young corpora lutea and not in aged corpora lutea, suggesting the non-equivalence of binding in vitro and ovarian response.

scholarly journals Studies on rat ovarian receptors for lutropin (luteinizing hormone). Interaction with β-subunit of sheep lutropin

1976 ◽  
Vol 160 (3) ◽  
pp. 615-619 ◽  
Author(s):  
K Muralidhar ◽  
N R Moudgal
Keyword(s):  
Biological Activity ◽  
Luteinizing Hormone ◽  
Cyclic Amp ◽  
Chorionic Gonadotropin ◽  
Lower Order ◽  
Ovarian Response ◽  
Β Subunit ◽  
Α Subunit ◽  
Human Choriogonadotropin

By using radioimmunoassay, the interaction of sheep lutropin (luteinizing hormone, LH) β-subunit with rat ovarian receptors was investigated. The binding of β-subunit was specific, although of much lower order than that of lutropin. Sheep lutropin β-subunit effectively inhibited the binding of human choriogonadotropin (chorionic gonadotropin, gCG) to the ovary, showing that both occupy the same sites. The binding of sheep lutropin β-subunit to ovary was not followed by any detectable increase in cyclic AMP. The ovarian response to lutropin in terms of cyclic AMP production was inhibited in the presence of free β-subunit. The α-subunit of lutropin, when used at concentrations where contamination with whole lutropin was negligible, enhanced the degree of binding of β-subunit; this did not lead to increased cyclic AMP in the tissue. Surprisingly, the binding of β-subunit in vitro was drastically decreased by the prior removal of all endogenous rat lutropin bound to receptors. The implications of these data are discussed in the light of the reported biological activity of the β-subunit.

INDUCTION OF OVULATION IN SHEEP BY INTRA-ADENOHYPOPHYSIAL INFUSION OF HYPOTHALAMIC EXTRACTS

1968 ◽  
Vol 42 (3) ◽  
pp. 383-389 ◽  
Author(s):  
E. DOMÁNSKI ◽  
K. KOCHMAN
Keyword(s):  
Luteinizing Hormone ◽  
Pituitary Gland ◽  
Median Eminence ◽  
Strong Evidence ◽  
Late Phase ◽  
Follicle Stimulating Hormone ◽  
Ovarian Response ◽  
Corpora Lutea ◽  
Seasonal Differences ◽  
Releasing Factors

SUMMARY The follicle-stimulating hormone releasing factor (FSH-RF) and luteinizing hormone-releasing factor (LH-RF) activity in sheep hypothalamic extracts and their action on the release of gonadotrophins from the pituitary gland has been studied by the infusion of extracts of the stalk and median eminence (SME) directly into the adenohypophysis of ewes in various phases of their non-cycling quiescent sexual period. The intra-adenohypophysial infusion of hypothalamic extracts during mid-anoestrus elicited no ovarian response, while similar infusion of the same extracts in the late phase of anoestrus, e.g. in the last 2–4 weeks before the onset of the breeding season, induced the growth and rupture of ovarian follicles as well as development of corpora lutea. This ovulatory response provides indirect but strong evidence for the ability of hypothalamic extracts to release gonadotrophins (FSH as well as LH) from the pituitary gland. The seasonal differences in the response of ewes to intra-adenohypophysial infusions of hypothalamic extracts suggest that the sensitivity of the adenohypophysis to the hypothalamic releasing factors varies during the year.

Tokishakuyakusan Stimulates Progesterone and Estradiol-17 β Production by Rat Granulosa Cells and Progesterone, Testosterone and Estradiol-17 β by the Residual Portion of the Follicle in Vitro

1991 ◽  
Vol 19 (02) ◽  
pp. 155-161 ◽  
Author(s):  
Satoshi Usuki
Keyword(s):  
Granulosa Cells ◽  
Cell Level ◽  
Testosterone Production ◽  
Progesterone Production ◽  
Preovulatory Follicles ◽  
Immature Rats ◽  
Serum Gonadotropin ◽  
Tissue Compartments ◽  
Stimulation Of

To examine the possible effects of Tokishakuyakusan (TS) on steroidogenesis by preovulatory follicles at the cell level, the expressed granulosa cells and remaining portion of follicles from pregnant mare's serum gonadotropin (PMS)-treated immature rats were incubated in vitro with increasing concentrations of TS for 3 h. TS significantly stimulated progesterone and estradiol-17 b production, with a predominant stimulation of progesterone, by the expressed granulosa cells, while testosterone production was not stimulated. In the remaining portion of the follicle, TS also significantly stimulated progesterone, testosterone and estradiol-17 b production. Similar to the effect produced by granulosa cells, the stimulatory effect of TS was stronger on progesterone than on testosterone and estradiol-17 b production. These results suggest that TS has a potent, direct stimulatory effect on steroidogenesis, especially progesterone production, by constituent tissue compartments of rat preovulatory follicles in vitro.

Changes in ovarian lysosomal populations of immature rats after pregnant mare serum gonadotropin (PMSG) treatment

Micron (1969) ◽  
1976 ◽  
Vol 7 (4) ◽  
pp. 325-326
Author(s):  
Edna A. Elfont ◽  
Michael J. Dimino ◽  
Joseph P. Roszka ◽  
Steven Malcom
Keyword(s):  
Pregnant Mare Serum Gonadotropin ◽  
Immature Rats ◽  
Serum Gonadotropin
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