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Effect of testosterone enanthate on follicular growth in rats
Author(s) -
Sawada Tsutomu,
Yamashita Yasushi,
Tamada Hiromichi,
Inaba Toshio,
Mori Junichi
Publication year - 1996
Publication title -
drug development research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.582
H-Index - 60
eISSN - 1098-2299
pISSN - 0272-4391
DOI - 10.1002/(sici)1098-2299(199604)37:4<208::aid-ddr2>3.0.co;2-p
Subject(s) - estrous cycle , medicine , endocrinology , testosterone (patch) , follicular phase , stimulation , biology
The effects of exogenous testosterone enanthate, a long‐acting testosterone ester, on estrous activity and reproductive performance in female rats were studied. An injection of 2.5–20.0 mg of testosterone enanthate delayed until 26.9–60.1 days the cycling of the estrous cycle in a dose‐dependent way; the treated rats began regular 4‐day estrous cycles 41.9–80.7 days after the injection. Subsequent reproductive performance was not different in the treated and control animals ( P > .05). Ovarian weight during estrous inhibition decreased steadily after treatment, but the uterine weight increased for a time. The ovaries contained follicles and interstitial cell islands, but no new ovulatory corpora lutea. The injection decreased the number of small follicles (250–549 μm), but increased the number of mature large follicles (≥550 μm; P < .05). The mean testosterone concentration in the peripheral plasma during estrous inhibition was higher than that before the treatment ( P < .05). Testosterone concentrations increased for a time after treatment ( P < .05), but decreased steadily thereafter. These results suggest that testosterone enanthate might be used for long‐term contraception; the effects seem to depend on testosterone. Continuous stimulation by the long‐term activity of testosterone inhibited the growth of small follicles but stimulated the growth of large follicles. © 1996 Wiley‐Liss, Inc.