Serum concentrations of progesterone, luteinizing hormone, follicle stimulating hormone and prolactin in pseudopregnant rats: effect of decidualization
De Greef, W.J.; Dullaart, J.; Zeilmaker, G.H.
Endocrinology 101(4): 1054-1063
1977
ISSN/ISBN: 0013-7227 PMID: 908264 DOI: 10.1210/endo-101-4-1054
Accession: 006400523
Serum progesterone and gonadotropin levels were determined in deciduomata-bearing and control pseudopregnant rats. The effects of hypophysectomy and/or hysterectomy performed on day 7 of pseudopregnancy on progesterone concentrations were investigated in order to detect a possible endocrine activity of decidual tissue. Pseudopregnancy lasted 14.0 .+-. 0.2 days in control rats and 22.1 .+-. 0.4 days in rats bearing decidual tissue. In control rats serum progesterone concentrations were about 80 ng/ml on days 5-8 of pseudopregnancy, whereas a gradual decrease to 20 ng/ml was observed between days 8 and 14. In deciduomata-bearing rats, progesterone concentrations on days 7 and 8 were higher than in control rats, and furthermore, elevated progesterone concentrations (> 50ng/ml) were observed until day 17. There was no difference in the number or maximal diameter of the corpora lutea on days 7, 9 and 11 between the 2 groups of rats. Serum LH [luteinizing hormone] concentrations remained relatively constant in control rats until day 8; thereafter, an increase was observed. In deciduomata-bearing rats LH concentrations on days 6-10 were somewhat lower than in control rats, and an increase in serum LH concentrations occurred after day 16 of pseudopregnancy. In both groups of rats serum FSH [follicle stimulating hormone] concentrations varied between 130 and 160 ng FSH RP[reference preparation]-1/ml, and on day 10 of pseudopregnancy only significantly lowerFSH concentrations were found in the sham-operated control animals. In control and deciduomata-bearing rats, 2 elevated levels of prolactin were observed daily: one at 0300 and one at 1900 h. In the control rats, the last elevation in serum prolactin was found on day 11 at 0300 h, whereas in rats with decidual tissue both prolactin surges were still present on day 16 of pseudopregnancy. A drastic decline in serum progesterone concentrations was observed in both groups of rats following hypophysectomy on day 7 of pseudopregnancy. The decrese in progesterone concentrations was less abrupt in deciduomata-bearing rats than in control rats. Following hysterectomy a decrease in progesterone concentratios was observed only in deciduomata-bearing rats. Combined hypophysectomy and hysterectomy in deciduomata-bearing rats resulted in a decrease in progesterone concentrations similar to the decrease that followed hypophysectomy in control rats without decidual tissue.