An Intracellular Lipoidal Cycle and its Disruption by Neutral Red

Abstract

A CYTOLOGICAL study has been carried out on fixed, living and frozen-dried acinous cells of the pancreas of the mouse. Observations on fixed preparations prepared by Baker's¹ sudan black technique have shown that zymogen granules are formed from certain lipoidal prozymogen bodies which originate from mitochondria in the form of small granules. The granular prozymogen bodies migrate towards the Golgi apparatus and finally establish contact with it. It seems quite possible that the Golgi apparatus makes some contribution to the lipoidal bodies to be included in, or to facilitate, the production of zymogen. The prozymogen bodies next leave the Golgi apparatus and become vacuolated so that each one comes to consist of an outer lipoidal sheath which envelops an inner immature zymogen granule. In the zymogen zone the lipoidal sheath is lost and a mature zymogen granule makes its appearance, usually with a small particle of lipid adhering to its surface.