| RESEARCH PAPER
|Year : 1992 | Volume
| Issue : 2 | Page : 94-97
Status of histamine receptor sub-types in the oesophagus of WLH chicken
Kalra Anoop, SP Verma, SK Garg, RP Uppal, BD Garg
To investigate the histamine receptor sub-types in the chicken oesophagus, the isotonic responsiveness of isolated oesophagus to histamine receptor agonists and antagonists was examined in vitro. Histamine and 2-pyridylethylamine (2-PEA) produced a concentration related contraction which was antagonized by mepyramine. Histamine did not produce relaxation of carbamylcholine contracted tissues although histamine-induced contraction was potentiated in the presence of cimetidine, phentolamine or propranolol. Dimaprit produced a concentration-dependant relaxation which was partly antagonized by cimetidine. Phentolamine and propranolol did not modify the dimaprit-induced relaxation. Longitudinal smooth muscles of chicken oesophagus seem to contain both H1 and H2 histamine receptors. The inhibitory H2 receptors appear to be usually masked by the overwhelming predominance of the excitatory H1receptors.
Source of Support: None, Conflict of Interest: None