Effects of angiotensin II on behavioral responses of defensive burying paradigm in rats.
The effects of angiotensin II (ATII) administered intracerebroventricularly in male Wistar rats in doses of 0.1, 0.5, and 1.0 micrograms, as well as of ATII (1.0 micrograms) + saralasin (SAR, an analog ATII) (5.0 micrograms), on behavioral responses of the defensive burying paradigm were studied. ATII-treated animals displayed significantly less defensive burying behavior (less time spent in defensive burying and less frequent burying than in vehicle-treated rats) in a dose-dependent manner. SAR at a dose of 5 micrograms did not affect burying behavior significantly; it also did not modify the inhibition effects of ATII on behavioral responses of the defensive burying test. These results provide evidence that ATII can exert anxiolytic actions on central transmitter systems mediating conditioned fear-related behaviors (i.e., defensive burying). The present study suggests that the defensive burying animal model is a rather sensitive test fulfilling the pharmacological criteria of dose-dependent sensitivity for studying the central effects of neuropeptides (e.g., ATII).
Tsuda
A
A
Department of Pharmacology, Kurume University School of Medicine, Japan.
Tanaka
M
M
Georgiev
V
V
Emoto
H
H
D000378:Agonistic Behavior / Q000187:drug effects*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D006185:Habituation, Psychophysiologic; D007276:Injections, Intraventricular; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012504:Saralasin / Q000494:pharmacology
D000804:Angiotensin II; D012504:Saralasin