Ultrastructural features of in vitro propagated rat liver cells

Morphometric study of the interphase nucleus in some radiosensitive and radioresistant mammalian cells

The radiosensitive cell populations, such as resting lymphocytes from thymus, spleen, lymph node and blood, have much smaller nuclei (Vn (nuclear volume) approximately 20 to 70 microns3) compared to radioresistant G0 cells from non-lymphoid tissues (liver, kidney, brain, heart; Vn approximately 75 to 2700 microns3). It is suggested that radiation-induced disorganization of nuclear structures and cell pycnosis (interphase death) are promoted in G0 lymphocytes because in normal physiological conditions their nuclei assume a higher degree of chromatin condensation. In contrast, dispersion of chromatin into larger nuclear volumes, such as those of most non-lymphoid G0 cells, may hinder or delay radiation-induced cell death.

Conditions affecting primary cell cultures of functional adult rat hepatocytes. II. Dexamethasone enhanced longevity and maintenance of morphology

Primary monolayer cell cultures of adult rat hepatocytes underwent change in morphology and substantial cell loss between 1 and 3 days postinoculation. Dexamethasone-supplementation (1 micronM) of the culture medium maintained the polygonal epithelial morphology of the hepatocytes and increased longevity such that over 80% of the cells survived for 3 days and at least 30% for 8 or 9 days. This enhancement of survival was obtained up to 48 hr postinoculation, but the earlier the time of dexamethason supplementation the greater the effect. Removal of dexamethasone resulted in a decrease in longevity. The positive effect of dexamethasone on longevity was observed following dexamethasone replacement of insulin in supplemented cultures, but the combination of insulin and dexamethasone resulted in poorer survival than with dexamethasone alone. The results are interpreted to indicate that dexamethasone provided a requirement of the in vitro environment for survival and suggest that elaboration of a complex medium is required to maintain hepatocytes in culture.

Conditions affecting primary cell cultures of functional adult rat hepatocytes. 1. The effect of insulin

The conditions for obtaining representative, primary adult rat hepatocyte cultures were explored. The methods applied included enzymatic liver perfusion which was nondestructive to hepatocytes, the prevention of aggregation of dissociated cells and the selective attachment of viable cells. These procedures yielded a recovery of 50% of the liver cells which gave rise to cultures representing 14% of the total liver cells. The cultures were composed of homogeneous epithelial-like cells cytologically similar to hepatocytes and possessed a number of liver-specific enzymes. There was virtually no cell division initially and most cells died between 24 and 48 hr. Insulin enhanced the attachment of the liver cells, altered their morphology, but did not prolong cell survival.