Influence of calcium removal from bath solution on isolated rat duodenum contractions.
In this study whether extracellular Ca++ is essential to produce an increase of tension of isolated rat duodenum by ACh, 5-HT, AVP and KCl-, was examined. KCl- and AVP-evoked contractions were almost totally prevented by Ca++ removal from bath solution. The increase of tension of isolated duodenum caused by ACh or 5-HT was totally prevented after adding nifedipine, a Ca++ channel blocker, into Ca free solution. Our results suggest that ACh or 5-HT utilizes intracellular as well as extracellular sources of Ca++ to produce contraction in rat duodenum, whereas AVP-or KCl evoked contraction was mainly due to influx of Ca from extracellular sources.
Süer
C
C
Department of Physiology, Erciyes University, Medical Faculty, Kayser, Turkey.
Erenmemisoglu
A
A
Temocin
S
S
Akar
S
S
Beydagi
H
H
Taspolat
I
I
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D004386:Duodenum / Q000187:drug effects; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D009543:Nifedipine / Q000494:pharmacology; D011189:Potassium Chloride / Q000494:pharmacology; D051381:Rats; D012701:Serotonin / Q000494:pharmacology
D001127:Arginine Vasopressin; D012701:Serotonin; D011189:Potassium Chloride; D009543:Nifedipine; D000109:Acetylcholine; D002118:Calcium