S. Ramaswamy et al., A STUDY ON THE VASOPRESSIN-INDUCED DELAY IN THE GASTROINTESTINAL TRANSIT IN MICE - POSSIBLE MECHANISM OF ACTION, Life sciences, 53(12), 1993, pp. 991-996
The effect of arginine vasopressin (AVP) on the gastrointestinal (GI)
transit and its possible mechanism were studied using charcoal meal te
st in mice. A dose related inhibitory effect was recorded. The effect
appears to be independent of the time allowed between AVP administrati
on and testing. The studies on the mechanism reveal that AVP acts with
out involving V1 and V2 vasopressin receptors.An almost complete rever
sal of the effect by physostigmine and potentiation by atropine indica
te that AVP might act through an inhibition of the release of acetylch
oline. However, the neural nicotinic receptors mechanisms do not seem
to contribute since hexamethoinium falied to modify the AVP action. Fu
rther, a partial antagonism by naloxone or prazosin pretreatment indic
ates that opioid and alpha1 adrenergic systems also contribute to this
action of AVP. However, the effect appeares to be independent of alph
a2 and beta Adrenergic systems since yohimbine and propranolol failed
to modify the same.