Use of the p-nitrophenyl phosphate method for the demonstration of acid phosphatase during starvation and cell autolysis in the planarian Polycelis tenuis Iijima.

Acid phosphatase activity is demonstrated employing p-nitrophenyl phosphate as substrate and lead acetate as coupler. The fine structural localization of the enzyme in starved planarian tissues is described. The method is used to pin-point starvation - induced acid phosphatase activity in relation to autophagy and crinophagy in the gland cells; autophagy, autolysis and cell death in parenchymal and gastrodermal cells and basement membrane lysis. Attention is also payed to the demonstration of muscle lysis. The histochemical implications of the method are discussed.