Vasoactive intestinal polypeptide (VIP): Effect on rabbit uterine smooth muscle in vivo and in vitro

Abstract

The effect of vasoactive intestinal polypeptide (VIP) on uterine smooth muscle electrical and mechanical activity in non-pregnant estradiol-treated rabbits was investigated using in vivo and in vitro methods. The studies were performed on spontaneous, oxytocin-, carbachol-, and prostaglandin-42 alpha-induced activity. VIP had a dose-related inhibitory effect on both myoelectrical and mechanical activity. The concentration needed for 50% inhibition (ID50) was 2 x 10(-10) mol VIP . 1(-1) (in vivo), an 6 x 10(-8) mol VIP . 1(-1) (in vitro). This inhibition was unaffected by the presence of atropine (10(-5) mol . 1(-1)), propranolol (10(-5)), phentolamine (10(-5)), naloxone (10(-5)), apamin (10(-5)), and tetrodotoxin (10(-5)). These findings indicate that VIP may act via a specific receptor on the smooth muscle and supports the hypothesis that VIP may be a neurotransmitter involved in the local nervous control of uterine smooth muscle activity.

The effect of apamin on non‐adrenergic, non‐cholinergic vasodilator mechanisms in the intestines of the cat.

“…We therefore conclude that, if this peptide exerts its effect at the level of the vascular smooth muscle cell, it does not do so by blocking receptors of any of the substances tested in this study. This conclusion is substantiated as regards VIP by observations made on uterine muscle tissue (Ottesen, 1981) and taenia coli (Mackenzie & Burnstock, 1980). However, a presynaptic action is not ruled out by these observations.…”

Nervous release of vasoactive intestinal polypeptide from the feline uterus: pharmacological characteristics.

“…The physiological significance of these possible myomotoric and secretomotoric nerves remains to be solved since in the present experiments neither the uterine smooth muscle activity nor the secretion were recorded. However, a role for the VIPergic nerves in the control of uterine smooth muscle activity is likely since VIP exhibits non-adrenergic, noncholinergic inhibition of uterine myoelectrical activity and contractions (Ottesen, Ulrichsen, Wagner & Fahrenkrug, 1979;Ottesen, Wagner & Fahrenkrug, 1980; 458 UTERINE VIP RELEASE Ottesen, 1981;. The effect of VIP on uterine secretion has not yet been examined.…”

Expression of VPAC1 receptor at the level of mRNA and protein in the porcine female reproductive system

“…In the human oviduct and uterus only the VIP binding and VPAC1 receptor protein band of 47kDa expression by immunoblot were detected (Bajo et al 2000). However, physiological studies clearly show that, for example, VIP increases in a dose-dependent manner the blood flow through the rabbit uterine muscular membrane (Ottesen 1981). The way of VIP action on the blood vessels is only partially elucidated.…”

“…The distribution of VIP receptors was not studied in the tissues of the oviduct and uterus but it is known that this peptide inhibits the activity of the muscular layer cells of the oviduct (Bredkjoer et al 1997) and uterus (Ottesen 1981). The binding of VIP was found to be hormone-dependent, as estradiol with progesterone were augmenting VIP binding in the ovariectomized rabbits (Ottesen et al 1985).…”