Characterization of the histamine releasing effect of neurotensin in the rat heart.
Bolus injections of neurotensin (NT) in the rat perfused heart elicited a transient, dose-dependent histamine release. The histamine releasing effect of NT appears to be independent of the heart rate and coronary perfusion pressure and it was not influenced by atropine, propanolol, prazosin, methysergide, ketanserin, indomethacin, morphine, lidocaine or by removal of the atria. However, it was potentiated by adenosine, inhibited by sub-stimulatory concentrations of NT and the mast cell membrane stabilizing drug cromoglycate but was unaltered by the calcium antagonist verapamil. The absence of calcium in the heart perfusate suppressed the histamine releasing effect of NT. These results suggest that the histamine releasing effect of NT in the rat heart results from a direct effect on ventricular mast cells and is calcium-dependent.
Rioux
F
F
Kérouac
R
R
St-Pierre
S
S
D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000502:physiology; D006321:Heart / Q000187:drug effects*; D006636:Histamine Release / Q000187:drug effects*; D008297:Male; D008407:Mast Cells / Q000187:drug effects; D009206:Myocardium / Q000166:cytology; D009496:Neurotensin / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D014700:Verapamil / Q000494:pharmacology
D009496:Neurotensin; D014700:Verapamil; D000241:Adenosine; D002118:Calcium