Effects of hyperthermia on Tetrahymena : I. Localization of acid hydrolases and changes in cell ultrastructure

Abstract

The effects of hypothermia on Tetrahymena pyriformis (E) were studied. Protein synthesis was greatly inhibited at elevated temperatures (33.5-34 [deg]C), although the rate of protein turnover was not initially greater than in controls. There was no evidence that cellular lesions induced by temperature shock resulted from a solubilization of lysosomal enzymes. More than 80% of both acid phosphatase and acid proteinase activity remained particle-bound, even in cells incubated at 34 [deg]C for prolonged periods. Ultrastructural studies revealed gross lesions in all types of cell organelles. These included a loss of tubules from mitochondria, disappearance of the rough endoplasmic reticulum, nuclear abnormalities, and a swelling of bodies tentatively identified as peroxisomes or primary lysosomes. Autophagic vacuoles which contained considerable membranous material seemed to accumulate during treatment, and membranous whorls and smooth-walled vesicles became quite common in the cytoplasm. Our studies are consistent with the suggestion [28] that, supraoptimal temperatures affect phospholipid-containing membranes in Tetrahymena.