Effect of steroids on ovarian neutral proteinases during ovulation in cyclic albino rats

Progesterone (0.5 mg/rat) and estradiol-17 beta (10 micrograms/rat) injections (im) on the morning of proestrous in cyclic female rats enhanced the ovulation rate (number of ova shed). These steroids also significantly (P less than 0.05) increased the activity of ovarian neutral proteinases, observed on the morning of estrus as compared to those in control and vehicle treated animals. Nonsteroidal estrogen antagonist, tamoxifen suppressed ovulation rate and ovarian neutral proteinase activity as compared to control, its vehicle and steroidal treatment. The results demonstrate a stimulatory effect of progesterone and estradiol 17 beta on ovulation and ovarian neutral proteinases.