A study on the vasopressin induced delay in the gastrointestinal transit in mice: possible mechanism of action.
The effect of arginine vasopressin (AVP) on the gastrointestinal (GI) transit and its possible mechanism were studied using charcoal meal test in mice. A dose related inhibitory effect was recorded. The effect appears to be independent of the time allowed between AVP administration and testing. The studies on the mechanism reveal that AVP acts without involving V1 and V2 vasopressin receptors. An almost complete reversal of the effect by physostigmine and potentiation by atropine indicate that AVP might act through an inhibition of the release of acetylcholine. However, the neural nicotinic receptors mechanisms do not seem to contribute since hexamethonium failed to modify the AVP action. Further, a partial antagonism by naloxone or prazosin pretreatment indicates that opioid and alpha 1 adrenergic systems also contribute to this action of AVP. However, the effect appears to be independent of alpha 2 and beta adrenergic systems since yohimbine and propranolol failed to modify the same.
Ramaswamy
S
S
Department of Pharmacology, Jawaharlal Institute of Postgraduate Medical Education & Research, Pondicherry, India.
Shewade
D G
DG
Tripathi
C D
CD
Tyagi
M G
MG
Tripathi
K D
KD
D000818:Animals; D001127:Arginine Vasopressin / Q000494:pharmacology*; D001285:Atropine / Q000494:pharmacology; D001522:Behavior, Animal / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005730:Ganglionic Blockers / Q000494:pharmacology; D005772:Gastrointestinal Transit / Q000187:drug effects*; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D051379:Mice; D010830:Physostigmine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D013045:Species Specificity; D013997:Time Factors; D015016:Yohimbine / Q000494:pharmacology
D005730:Ganglionic Blockers; D006584:Hexamethonium Compounds; D001127:Arginine Vasopressin; D015016:Yohimbine; D018738:Hexamethonium; D001285:Atropine; D010830:Physostigmine; D011433:Propranolol