Inhibition of LH-induced ovulation in the rat by a hormonal antagonist

A chemically deglycosylated derivative of ovine luteinizing hormone (LH) exhibited appreciable binding to the receptor but had minimal steroidogenic activity. In immature female rats primed with pregnant mare serum gonadotropin, the deglycosylated LH showed low ovulation-inducing activity. Ovulation induced by ovine LH was significantly inhibited by subcutaneous administration of the derivative. The results indicate that deglycosylated pituitary LH, can antagonize the action of the native hormone in vivo.