The presence of corticotropin-like and opiate-like activities in tissues of adult sea lamprey, Petromyzon marinus L.

Sexually mature landlocked sea lamprey were captured during their upstream migration. Different tissues, including the brain, pituitary, heart, liver, gut, testis, and ovary, were dissected from the animals and an acetone powder was prepared from each tissue. The tissue acetone powders were subjected to heat treatment and were then extracted with an acidic medium in order to inactivate any proteases present. The resulting acid acetone powders were then tested for their ability to stimulate corticosterone production from isolated rat adrenal cells and to displace the binding of D-Ala2-D-Leu5-[tyrosyl-3,5-3H]-enkephalin to rat brain membranes. It was found that the brain and liver contained steroidogenic activity while opiate activity was detected in the heart, liver, gut, brain, and pituitary. No steroidogenic activity was found in the heart, ovary, testis, gut, and pituitary while ovary and testis did not contain assayable opiate activity. None of the tissues contained beta-endorphin-like immunoreactivity.