Materials with opiate receptor binding activity in bovine testis and ovine pancreas.

Two groups of opiate-like materials, one with a molecular weight equal to or greater than 5000 daltons and another with a molecular weight smaller than 5000 daltons as judged by gel filtration on Sephadex G-25, were detected in bovine testes. The existence of opiate-like materials with a molecular weight smaller than 5000 daltons was demonstrated in ovine pancreas. The pancreatic fraction most strongly adsorbed on CM-cellulose possessed the highest opiate receptor binding activity. Bovine testis contained corticotropin-like material(s) which stimulated corticosterone production by isolated rat adrenal cells.