An Atypical Mitochondrial Form in Normal Rat Liver

Morphological ly atypical mi tochondr ia have been reported by m a n y investigators. Those possessing a cupped shape have been found in presumably normal cells of endocrine organs of widely differing species. Christensen and C h a p m a n (1) observed them in interstitial cells of the a lbino ra t testis and report tha t they have also seen t hem in Sertoli cells of the same tissue. T h r o u g h personal communicat ions , they report observations of cupshaped rni tochondria by Fawcet t in opossum Leydig cells, and by I to in nurse cells of Drosophila testis. Two reports of similarly shaped mitochondr ia have been made in conjunct ion with spermatogenesis, specifically in conjunct ion with the formation of the nebenkern of the grasshopper spermatozoa (2) and the nebenkern homologue in the scorpion (3). I t thus appears tha t cup-shaped mi tochondr ia are found relatively frequently in testicular tissue. DeRober t is and Sabat ini (4) report a complex mi tochondr ia l change in the adrenal cortex of the normal hamster , which they believe to be a degenerat ing form. These mitochondr ia bear a striking resemblance to those described by Christensen and C h a p m a n (1). M u n g e r (5) has shown tha t Beta cells of the islets in embryonic mouse pancreas sometimes have cupshaped mitochondria .