| RESEARCH PAPER
|Year : 1981 | Volume
| Issue : 3 | Page : 225-232
Presence of H1 excitatory and H2 inhibitory histaminergic receptors in guinea-pig gall bladder
RJ Shah, SC Verma
Histamine and 2-(2-pyridyl) ethylamine (PEA), a specific H1 receptor agonist, produced dose dependent contraction of guinea-pig gall bladder strip.Mepyramine maleate, the specific H1 receptor antagonist inhibited the responses to histamine and PEA, while metiamide the specific H2 receptor antagonist, had no significant effect. Dimaprit, a specific H2 receptor agonist, produced dose related relaxation of the depolarised gall bladder strip. Metiamide inhibited the responses to dimaprit while mepyramine did not produce any significant effect on the responses to dimaprit. Reserpine pretreatment (5 mg/kg. ip 24 h) did not significantly affect the responses to histamine. Neither atropine sulphate nor propranolol significantly altered the responses to histamine. Our findings suggest that the gall bladder contains excitatory Hl histaminergic receptors and inhibitory H2 histaminergic receptors. Further more, responses are due to its direct effects on the smooth muscle.
R J Shah
Source of Support: None, Conflict of Interest: None