Anomalous responses to histamine stimulation of guinea-pig oesophageal muscularis mucosae.
The incomplete tachyphylaxis of the contractile response to the H1-stimulants observed on guinea-pig oesophageal muscularis mucosae seems to be H2- and H3-antagonist as well as atropine- and tetrodotoxin-resistant. Lidocaine and eserine partially prevented this process probably by a mechanism independent of their main activity. The dualistic antagonism exerted by mepyramine and methysergide on reproducible histamine responses could be explained by a kinetic condition of "hemi-equilibrium state" together with changes of drug-receptor interaction and by non-specific properties of methysergide. On the whole, the present data indicate that the role of histamine in this tissue has still to be defined.
Barocelli
E
E
Institute of Pharmacology and Pharmacognosy, Department of Pharmacy, University of Parma, Italy.
Chiavarini
M
M
Morini
G
G
Ballabeni
V
V
Vitali
T
T
Silva
C
C
Impicciatore
M
M
D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004361:Drug Tolerance; D004947:Esophagus / Q000502:physiology*; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D008012:Lidocaine / Q000494:pharmacology; D008784:Methysergide / Q000494:pharmacology; D009092:Mucous Membrane / Q000502:physiology; D009119:Muscle Contraction / Q000187:drug effects; D010830:Physostigmine / Q000494:pharmacology; D011738:Pyrilamine / Q000494:pharmacology; D011968:Receptors, Histamine / Q000502:physiology*; D011969:Receptors, Histamine H1 / Q000502:physiology; D011970:Receptors, Histamine H2 / Q000502:physiology; D018100:Receptors, Histamine H3; D013779:Tetrodotoxin / Q000494:pharmacology
D011968:Receptors, Histamine; D011969:Receptors, Histamine H1; D011970:Receptors, Histamine H2; D018100:Receptors, Histamine H3; D013779:Tetrodotoxin; D001285:Atropine; D006632:Histamine; D008012:Lidocaine; D010830:Physostigmine; D011738:Pyrilamine; D008784:Methysergide