Effect of acute, but not chronic ethanol treatment on somatostatin secretion in rat hypothalamic neurons

To examine the possible involvement of somatostatin in growth hormone modifications induced by ethanol, we examined: (1) the effects of chronic ethanol exposure of cultured hypothalamic neurons on somatostatin content and mRNA levels; (2) the acute effect of ethanol on somatostatin release stimulated by N-methyl-D-aspartate (NMDA). The results showed that 8 days of ethanol exposure (10-100 mM) did not decrease somatostatin content or somatostatin mRNA levels. Ethanol treatment alone had no significant effect on cell morphology or on protein content. In contrast, acute application of ethanol in 8 day-old cultures significantly reduced (50 mM) or completely blocked (100 mM) somatostatin release elicited by 50 microM NMDA without modifying basal release. We conclude that chronic ethanol treatment to concentrations up to 100 mM has no effect on somatostatin biosynthesis in fetal rat hypothalamic neurons, while weaker concentrations decrease NMDA-induced somatostatin release.