Effect of cycloheximide on the fine structure of corpus luteum in intact and hypophysectomized rats.

In rats, one large intravenous dose of cycloheximide leads to extensive development of two types of membrane-formations in the cells of corpora lutea, within two hours. Both the laminated dense bodies (concentric layers of smooth membranes showing high electron density) and the tubular aggregates (tightly packed smooth tubules with diameter smaller than usual) exhibited obvious connections with endoplasmic reticulum membranes. The reorganization of tubular aggregates gave rise to 'crystalloids' showing hexagonal symmetry. The crystalloids, being obviously unstable, were transformed into smooth fingerprints (concentric arrays of paired agranular membranes showing the same density as endoplasmic reticulum membranes). Hypophysectomy, performed 24 hours previously, moderated but did not totally abolish the development of membranous configurations. The described effect of cycloheximide is considered to represent cellular injury, probably due to membrane-denaturation. [ABSTRACT FROM AUTHOR]