Swelling of astroglia in vitro and the effect of arginine vasopressin and atrial natriuretic peptide.

Numerous neuropathological conditions are accompanied by astroglial swelling which may contribute to secondary neuronal damage. From 4-27 days in vitro, swelling of astroglial cells was induced by hypo-osmolar solutions and high K+ solutions and the cells were examined by microscopy and flow cytometry. Regulatory volume decrease was observed beginning after approximately 30 minutes and was accompanied by increased membrane activity. Arginine vasopressin caused gradual persistent astroglial swelling. Atrial natriuretic peptide caused retraction of the astroglial cell processes but did not significantly alter the swelling induced by hypo-osmolar or elevated K+ solutions. The membrane mechanisms responsible for the control of astroglial cell volume did not appear to be specific for mature astroglia, rather they are present at all developmental stages.