Ultrastructure of the Mammalian Adrenal Cortex

Abstract

Publisher Summary This chapter discusses the systematic study of the ultrastructural morphology of the adrenal cortex in mammals..The findings of comparative morphology are also discussed. It is difficult to define in a general way the ultrastructural characteristics of the adrenal cortical cell of vertebrates; however, two features must be mentioned: (1) the importance of the smooth endoplasmic reticulum which is well developed, and the relatively poor development of the ergastoplasm; and (2) the frequency with which atypical differentiations are found inside the mitochondria, such as replacement of the usual cristae by tubules and vesicles. Biochemical findings concerning the biosynthesis of steroid hormones seem to indicate that a frequent switch occurs between the smooth endoplasmic reticulum and the mitochondria. It is difficult to define exactly which morphological phenomena, at the ultrastructural level, correspond to this phenomenon. It is unlikely that mitochondria can adopt the configuration that has been described as “open form mitochondria.” However, it is likely that they are able to produce digitations which can enter into close contact with the smooth endoplasmic reticulum or the liposomes, forming associations, or “complexes,” of mitochondria and smooth endoplasmic reticulum or mitochondria and liposomes.