Abstract
Conclusion
This work demonstrates that the inhibition of gonadotropin-induced ovulation by an extract of the bovine pineal gland is caused by the presence of a neuraminidase-type enzyme that rapidly deactivates the HCG. It is of interest to note that a gonadotropin-inhibiting substance isolated from bovine pituitary extracts, which is capable of inhibiting the ovarian weight increase caused by follicle-stimulating hormone and HCG in rats, has been found to contain a neuraminidase enzyme (9).
Thus the present paper may help to elucidate the reported gonadotropin-inhibiting properties of several pineal extracts. Where previous studies (10–12) have demonstrated that the extracts suppress the stimulatory effect of HCG, human menopausal gonadotropin, or PMS on the rodent gonad or uterus (an effect not caused by melatonin (10)), the presence of this neuraminidase-type enzyme may now explain this inhibition of the action of gonadotropin.
Get full access to this article
View all access options for this article.