Enkephalin production by the corpus luteum.

In search of Early pregnancy factors, on the base of Kentsin, the sole molecule embryo-specific, we detected the presence of Enkephalin in the Mouse ovary, in Bovine and Human corpus luteum. In the Mouse the Met-Enkephalin release by the ovary seems to be stimulated by the oviduct in presence of the embryo. In vitro Met enkephalin release by Bovine Corpus luteum is about 0.5 to 1. pMole/mg of fresh tissue/24 Hours. This release is not increased in presence of trophoblastic tissue. The content of the fresh tissue is between 0.7 and 1.9 picomoles par gram of Human tissue, and 0.9 picomoles for Bovine tissue. We determine the presence of Leu-Enkephalin and Met-Enkephalin Arg-Gly-Leu. The ratios observed confirm a ProEnkephalin A expression in the Ovary. The roles of these opioid peptides is discussed in term of ovum transport, Granulosa cell physiology and Early pregnancy factors.