Effect of bacterial endotoxin on secretion and synthesis of vasopressin during saline load in rats.

Secretion and synthesis of vasopressin was studied in adult male Wistar rats receiving lipopolysaccharide in a dose of 250 microg/100 g body weight and subjected to moderate osmotic stimulation (2% NaCl perorally for 6 days). Lipopolysaccharide stimulated secretion of vasopressin into the blood. It should be emphasized that the content of vasopressin mRNA in gigantocellular nuclei of the hypothalamus decreased, which probably reflected intensification of its translation. The observed changes and slight increase in transcription of the vasopressin gene (determined by the content of heterogeneous nuclear RNA) provide intensive secretion of this neurohormone into the blood.