Intracerebroventricular angiotensin II injection does not elicit specific appetite for sodium in the rat

The effect on sodium appetite of a single intracerebroventricular (IVT) injection of 1 microgram angiotensin II (AII) was studied in 264 young female CFY rats, comparing control and water depleted groups. The choice of demineralized water and 0.9, 2, 3 and 4% NaCl solution or 0.9% NaCl and 5% glucose solution was offered to the animals. During the 12-25 minute long dipsogenic action of AII, sodium intake was significantly increased as compared to the control group. Together with sodium intake water and glucose intake was found to increase proportionally, so the sodium appetite did not change significantly. At the same time, AII significantly increased the rate of sodium intake and the sodium appetite when a choice of water and NaCl was offered, and the basis of comparison was the water depleted group. When water was changed for 5% glucose, the animals receiving AII showed no significant sodium appetite, and drank so much glucose solution that their blood glucose increased to 202 +/- 26 mg/dl, and glucose appeared in their urine. The conclusion was drawn that AII does not cause an acute, specific alteration in sodium appetite.