Mitochondrial Changes in the Adrenocortex of Normal Hamsters

The considerable concentration of mitochondria found in the different zones of the adrenal cortex has been described with the light and with the electron microscope (1). (Palade, (2) in his general description of the fine structure of mitochondria, pointed out the special tubular structures found within the mitochondrial matrix. In addition to the adrenal cortex and other sites of steroid secretion (3), the lack of typical mitochondrial "cristae" has also been recognized in protozoa (see reference 4), and insects (5).) Recent biochemical work demonstrating the intimate relationship of mitochondria to the synthesis of steroid hormones (6, 7), has also contributed to the development of interest in studies on the submicroscopic form of this cell organelle (8). Within a general program of study of the histophysiology of the adrenal cortex of different species, we became interested in certain changes observed in the morphology and structure of mitochondria in the deeper regions of the cortex of normal hamsters. These changes lead to a flattening and lamination of certain mitochondria and then to the concentric apposition of several of them to form large lamellated chondriospheres. The adrenal cortex of male hamsters were fixed in an isosmotic solution of osmium tetroxide containing polyvinylpyrrolidone and balanced ions (9) and thin sections were observed with an RCA 2E microscope with a compensated objective lens. The cytoplasm of all the zones of the cortex is filled with large number of mitochondria while the amount of lipides is scarce in this species (Fig. 1). The interspersed hyaloplasm is also very scanty and shows few elements that can be recognized as endoplasmic reticulum, dense particles, or Golgi substance. Some large clear vacuoles are observed in the hyaloplasm the significance of which is still not clear to us, but which in some cases could be interpreted as canaliculi communi-