Relative sensitivity of the corpus luteum of different days of pregnancy to LH-deprivation in the rat and hamster.
Deprivation of endogenous LH by LH antiserum (LH A/S) in 6-day pregnant rats did not affect the luteal or serum progesterone within 24 h. LH A/S treatment on day 7 or 8 of pregnancy, however, caused a 70 and 92% reduction in luteal progesterone, respectively, within 24 h. Serum levels of progesterone showed a similar reduction. In the case of pregnant hamster, unlike the rat, there was a significant decrease in progesterone in the serum, luteal and non-luteal compartments whether the A/S was administered on day 4, 5 or 6. There was more than a 10-fold increase in the luteal cholesterol esters within 24 h whether the A/S was given on day 6, 7 or 8 of pregnancy in the rat. Rat corpora lutea of days 6 and 8 of pregnancy reacted in a like manner to LH-deprivation, showing an increased utilization of [U-14C]glucose to form 14CO2 in vitro. In the rat, LH (25 mug NIH-S19) administration in vivo either on day 6 or day 8 of pregnancy, caused within 2 h an increase in serum and non-luteal progesterone, but luteal progesterone was unchanged. On the other hand, LH administration to hamsters on day 8 of pregnancy caused an increase in progesterone levels in serum, luteal and non-luteal tissue. Incubation of corpora lutea isolated from untreated 6- and 8-day pregnant rats with LH brought about an increase in progesterone secretion into the medium in both cases. The results show that, even though LH-deprivation does not apparently affect progesterone concentration in the corpus luteum of 6-day pregnant rats, it does affect other metabolic parameters such as glucose utilization and cholesterol turnover, suggesting that the corpus luteum of early pregnancy exhibits a continuous dependency on LH for the maintainence of metabolic functions.
D000818:Animals; D000937:Antigen-Antibody Reactions; D003338:Corpus Luteum / Q000378:metabolism / Q000502:physiology*; D006224:Cricetinae; D005260:Female; D005947:Glucose / Q000378:metabolism; D007106:Immune Sera; D007986:Luteinizing Hormone / Q000172:deficiency / Q000276:immunology / Q000494:pharmacology / Q000502:physiology*; D010053:Ovary / Q000187:drug effects / Q000502:physiology; D011247:Pregnancy; D011270:Pregnancy, Animal; D011374:Progesterone / Q000097:blood / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D013997:Time Factors
D007106:Immune Sera; D011374:Progesterone; D007986:Luteinizing Hormone; D005947:Glucose