Acetylcholine mediation of the contractile response to histamine in human bladder detrusor muscle.
In Krebs solution, histamine evokes in human bladder detrusor muscle strips a dose-dependent contractile response which consists of two pharmacologically distinct responses: a high-sensitivity response evoked at 0.4-2 microM histamine, which is potentiated by neostigmine (0.1 microM) or blocked by atropine (0.1 microM) or ranitidine (1 microM); a low-sensitivity response evoked at 4-40 microM histamine and blocked by dimethindene or diphenhydramine. These findings suggest that the contractile response to low doses of histamine is mediated by acetylcholine released from a site proximal to the muscle. This effect of histamine seems to be mediated by a site which is insensitive to the H1 antagonists dimethindene and diphenhydramine but blocked by the H2 antagonist ranitidine.
Rubinstein
R
R
Department of Physiology and Pharmacology, Tel Aviv University Sackler School of Medicine, Israel.
Nissenkorn
I
I
Cohen
S
S
D000109:Acetylcholine / Q000502:physiology*; D001285:Atropine / Q000494:pharmacology; D004115:Dimethindene / Q000494:pharmacology; D004155:Diphenhydramine / Q000494:pharmacology; D006632:Histamine / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000187:drug effects*; D009388:Neostigmine / Q000494:pharmacology; D011899:Ranitidine / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects
D009388:Neostigmine; D004115:Dimethindene; D001285:Atropine; D006632:Histamine; D011899:Ranitidine; D004155:Diphenhydramine; D000109:Acetylcholine