The anovulation in female mice resulting from postnatal injections of estrogen is correlated with altered levels of CD8+ lymphocytes.
OBJECTIVE
Injections of estradiol-17 beta (E2) are known to both induce anovulation and alter lymphocyte maturation in female mice. The current study examined whether the two events are related.


METHODS
Female (C3H/HeJ x 129J)F1 (C31) mice were injected with 20 micrograms of E2 from 0-3 days, or from 3-6 days, postpartum. At 8, 12, 20, 32, or 40 weeks of age, the animals were killed, T lymphocytes were characterized, and ovaries were histologically examined for the presence of corpora lutea.


RESULTS
Animals injected with E2 from 0-3 days postpartum had percentages of CD8+ thymocytes and CD8+ splenocytes that were always lower than in noninjected females, and the E2-injected animals never ovulated, even by 40 weeks of age. In contrast, animals injected with E2 from 3-6 days of age had percentages of CD8+ thymocytes and CD8+ splenocytes that, although initially lower than in control females, attained control values by 32 weeks of age. In addition, at 32 weeks of age a number of the 3-6-day E2-injected females ovulated, whereas at earlier ages none had. Further, injections of E2 had little effect on the percentages of CD4+ thymocytes and splenocytes in these animals.


CONCLUSIONS
The results suggest that E2-induced anovulation in C31 female mice is correlated with decreased levels of CD8+ lymphocytes, and an increased CD4+/CD8+ lymphocyte ratio.
Deshpande
R R
RR
Department of Biological Sciences, State University of New York at Binghamton 13902-6000, USA.
Chapman
J C
JC
Michael
S D
SD
D000818:Animals; D000858:Anovulation / Q000139:chemically induced / Q000276:immunology*; D016516:CD4-CD8 Ratio; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology*; D003338:Corpus Luteum / Q000187:drug effects; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D006410:Hematopoiesis / Q000187:drug effects*; D051379:Mice; D008809:Mice, Inbred C3H; D009929:Organ Size / Q000187:drug effects; D010053:Ovary / Q000187:drug effects; D013950:Thymus Gland / Q000187:drug effects
D004958:Estradiol