| RESEARCH PAPER
|Year : 1976 | Volume
| Issue : 4 | Page : 221-226
Effect of histamine on chicken blood pressure and isolated smooth muscle preparations
SS Yadav, A Ahmad
Histamine response on chicken arterial blood pressure was characterized with a sharp fall followed by a rise. The depressor response of histamine in graded doses (1 to 8 (g/Kg. i. v.) was linear when plotted against its log doses. Blockade of histamine response on blood pressure with diphenhydramine was less in intensity and duration when compared with that of promethazine. Antihistaminic produced a marked and sustained rise in fowl blood pressure.
Histamine in lower concentrations (2.5 x10-8 to 2 x 1 O-7 (g/ml) relaxed the isolated ileum of chick and this relaxation was blocked by pronethalol. Histamine in higher concentrations 4 x 1 O-7 to 8 x 1 O-7(g/ml) produced contractile response which was blocked both by promethazine and diphenhydramine. ED50 of histamine on chick ileum and oviduct, calculated from cumulative dose response curve, were 1 O-6M and 5 x 10-8 M respectively.
S S Yadav