Immunoreactivity of Vasoactive Intestinal Peptide in submucosal neurons of the gastrointestinal tract of alloxan-diabetic Sprague Dawley rats

Vasoactive intestinal peptide (VIP) belongs to a group of peptides with the same prohormone precursor found in nerves in a wide range of tissues, including the gastrointestinal tract (GIT). VIP is also found in the central nervous system and autonomic ganglia where they exist as neurotransmitters. In the gut VIP is found in the submucosal and myenteric plexus and it modulates gut motility, specifically it contracts the longitudinal and circular muscle fibres and relaxes the pyloric and lower esophageal sphincters. Hypersecretion of VIP has been reported to result in watery diarrhoea-hypokalaemia-hypochlorhydria (WDHH) syndrome, characterized by hyper motility and dehydration. VIP has also been implicated as one of the neurotransmitters involved in erection, and some VIP analogues have been successfully used in the management of erectile dysfunction in diabetics. The purpose of this study is to determine whether the VIP-producing neurons in the GIT contribute to the reported decrease in the level of VIP in diabetics. Alloxan diabetic rats, maintained in hyperglycemic state for 60 days were sacrificed and specimens from their stomach and intestines were stained immunohistochemically for VIP-secreting neurons. Results showed that the imunoreactivity of VIP-secreting neurons in the submucosa of the stomach and small intestine were significantly reduced in alloxan-diabetic Sprague Dawley rats when compared with control. This result suggests that VIP-producing neurons in the GIT may play a significant role in the reported reduced levels of VIP in diabetics, and implies that VIP secreted by these neurons may contribute , in a paracrine manner, to some of the motility complications associated with diabetes mellitus.

Bombesin Immunoreactivity in the stomach and small intestine of alloxan-diabetics Sprague Dawley rats.

Bombesin is a neuroendocrine peptide found in the submucosal nerve endings in the esophagus, stomach and small intestine. It is reported to stimulate the release of gastrointestinal hormones, control satiety, stimulate gastrointestinal motility, and also stimulate cellular proliferation which results in wound healing. Transient increases in bombesin concentration in the brain and serum (later followed by decrease in serum concentrations) have been reported in hyperglycemic states. The aim of this investigation is to determine the effect of hyperglycemia on bombesin secreting neurons in the submucosa of the GIT and the possible contribution of such changes to some diabetic complications. Result showed decreased immunoreactivity to bombesin in the sub mucosal neurons of the stomach and small intestine of alloxan-diabetic Sprague-Dawley rats. We conclude that the reduced immunoreactivity of bombesin in these submucosal neurons, may contribute to the reduced paracrine-induced peristalsis, observed in diabetics. It may also contribute to poor wounds healing in diabetics.

Bombesin Immunoreactivity in the stomach and small intestine of alloxan-diabetics Sprague Dawley rats.

Bombesin is a neuroendocrine peptide found in the submucosal nerve endings in the esophagus, stomach and small intestine. It is reported to stimulate the release of gastrointestinal hormones, control satiety, stimulate gastrointestinal motility, and also stimulate cellular proliferation which results in wound healing. Transient increases in bombesin concentration in the brain and serum (later followed by decrease in serum concentrations) have been reported in hyperglycemic states. The aim of this investigation is to determine the effect of hyperglycemia on bombesin secreting neurons in the submucosa of the GIT and the possible contribution of such changes to some diabetic complications. Result showed decreased immunoreactivity to bombesin in the sub mucosal neurons of the stomach and small intestine of alloxan-diabetic Sprague-Dawley rats. We conclude that the reduced immunoreactivity of bombesin in these submucosal neurons, may contribute to the reduced paracrine-induced peristalsis, observed in diabetics. It may also contribute to poor wounds healing in diabetics.

Effect of water extract of the whole unripe fruit of Momordica Charantia, on the blood glucose concentrations of alloxan-diabetic Sprague Dawley rats

Medicinal values have been ascribed to Momordica charantia, a fruit commonly eaten in the Indian subcontinent and the Caribbean. The fruit consists of a green bark, which turns yellow when ripe. The bark covers a juicy pulp, which contains numerous seeds. One of the medicinal properties ascribed to this fruit, is its use in the control of blood glucose in Type 1 model of experimental of experimental animals. It has also been reported to decrease blood glucose concentrations in Non Insulin Dependent Diabetes Mellitus (NIDDM) patients. Extracts from different parts of the fruit have been investigated for hypoglycemic properties. Results of these investigations have been varied. In this study, the hypoglycemic property of the water extract from the whole fruit of the unripe Momordica charantia was investigated. Results showed that oral 'ad libitum' administration of this extract significantly reduced fasting blood glucose concentrations in Alloxan-diabetic Sprague Dawley rats (AU)