Involvement of luteinizing hormone in the implantation process of the rat

Abstract

The use of specific anti-FSH and anti-LH substances has shown that LH is the only pituitary gonadotrophin involved in the implantation process. Using different dosages of LH antiserum at different time intervals, it has been possible to arrive at a minimum effective dose (0.05 ml) which, when given on the 4th day at 10.00 hours, results in inhibition of implantation on the 8th day. We have shown that, at this dose, the antiserum is mainly inhibiting the oestrogen surge. It is proposed that an LH surge precedes an oestrogen surge on Day 4 of pregnancy.