Histamine-evoked potassium release in the mouse and guinea pig pancreas.
An investigation was made of the effects of histamine on the K+ concentration in the effluent in superfused guinea pig and mouse pancreatic segments. The effect of acetylcholine (ACh) was examined for comparison. Histamine evoked a dose-dependent and transient increase in the K+ concentration in the effluent (K+ release) but is less potent compared to the cholinergic agonist, ACh. At the same doses histamine and ACh evoke a much larger K+ release from mouse superfused pancreatic segments followed in the poststimulus period by a reuptake of K+. However, this reuptake of K+ was not observed in guinea pig superfused pancreatic segments. On the other hand, the cholinergic antagonist, atropine, completely abolished the K+ release in response to ACh and histamine from mouse and guinea pig pancreatic segments. Our results show the involvement of histamine in the control of K+ release in pancreatic tissue, with significant differences in the observed responses between species.
Rosado
J A
JA
Department of Physiology, Faculty of Veterinary, University of Extremadura, Cáceres, Spain.
Tapia
J A
JA
García
L J
LJ
Salido
G M
GM
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology*; D066298:In Vitro Techniques; D051379:Mice; D010179:Pancreas / Q000187:drug effects / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D013997:Time Factors
D001285:Atropine; D006632:Histamine; D000109:Acetylcholine; D011188:Potassium