Abstract

Autoradiographs of the ampullate gland of the spider (Araneus sericatus) made after the injection of labeled acetylcholine (ACh) showed localization along the outer membrane of the epithelial cells. It was found that the amount of labeled material localized along the membrane could be reduced by atropine and by high concentrations of diisopropylfluorophosphate (DFP). Stimulation of protein synthesis in the silk gland was found with ACh and low dosages of DFP. At these concentrations DFP did not reduce the amount of labeled material on the membranes. The decrease of grain counts on the membrane at low concentrations of labeled ACh could be prevented by pretreatment with low concentrations of DFP.