effects of intracerebroventricular injection of histamine and h1, h2 receptor antagonists on electrocardiographic parameters in broiler chickens

the aim of this study was to assess the effects of exogenous histamine and h1 and h2 central receptorson electrocardiographic (ecg) parameters, heart rate and mean electrical axis in broiler chickens. for thispurpose, ross broiler chickens (750-800 g weight) received intracerebroventricularly (icv) histamine.moreover, to determine the receptors involved in histamine-induced alterations in ecg changes, h1 and h2blockers were administered to histamine-treated chickens. all ecgs were standardized at 1 mv = 20 mm,with paper speed of 50 mm/sec. leads і, іі, ііі, avr, avl and avf were recorded. injection of histamine(200 and 300 μg) decreased the duration of t wave and qrs complex and elevated the heart rate ascompared to the control group (p