The drinking response of the chicken to peripheral and central administration of angiotensin 11

Intravenous injection of Ang II (val⁵ angiotensin II amide) elicited an immediate drinking response in the domestic fowl which lasted at least 20 minutes. The minimal dosage needed was 300 μg. Intracranial injection of 10 μg Ang II through cannulas implanted in the anterior diencephalon caused a significant increase in water intake. The minimal intracranial dosage of Ang II which evoked drinking was 2.5 μg. Intracranial injection of isotonic KCl inhibited the drinking response induced by intravenously injected Ang II when administered simultaneously. This suggests that drinking caused by both intravenous or intracranial injection of Ang II is activated through identical brain regions. The positive drinking response of the chicken to repeated consecutive intracranial injections of Ang II declined from the first injection through the following ones.