Water and NaCl intake of chicks as mediated by angiotensin II, renin, or salt deficiency.

ABSTRACT

Water, feed and NaCl intakes were measured in response to angiotensin II (ANGII) injected SC and ICV, and renin injected ICV, as well as to dietary salt deficiency in female broiler chicks (Gallus domesticus). In the first experiment, SC (100 micrograms/bird) and ICV (10 micrograms/bird) ANGII injection resulted in increased initial water intake. An additive effect on drinking was noted in response to consecutive daily SC injections. In addition, feed efficiency and growth were depressed following repeated ANGII injections (p less than 0.001). In a 2nd experiment, ICV ANGII stimulated increased cumulative water intake through 18 hours postinjection (p less than 0.05). Intake of 3.0% NaCl solution and feed was unaffected through 48 hours. Renin (1 microgram ICV) failed to affect cumulative water intake up to 48 hours postinjection. In the third experiment, dietary salt deficiency reduced feed intake after just 48 hours on salt-deficient diets (p less than 0.01), and growth and feed efficiency were significantly impaired (p less than 0.001) through 20 days of age. Intakes of NaCl solutions (0.8, 0.7 or 0.6%), however, were unaffected in salt-deficient vs. control birds. While the chicks in these experiments demonstrated a consistent drinking response to ANGII when injected peripherally or centrally, a salt appetite could not be elicited in these birds by components of the renin-angiotensin system or by dietary salt depletion.