Neuroendocrine Control of the Hepatopancreas in the Crayfish Procambarus clarki

Abstract

Removal of eyestalks from unfed crayfish result In a decrease in total nitrogen content of the hepatopancreas, a marked rise in pH of the digestive juice, a decrease in amylolytic activity of the digestive juice, and a loss of RNA from the hepatopancreas. Starvation of intact crayfish result in a slight rise in pH of the digestive juice, a marked increase in amylase content of the hepatopancreas, and an increase of amylase in the digestive juice. A neuroendocrine substance from the eyestalk stimulates synthesis of RNA by the hepatopancreas. It is hypothesized that a neuroendocrine substance from the eyestalk is responsible for stimulating RNA synthesis by the hepatopancreas and that this RNA is responsible for synthesis of amylase in the hepatopancreas.