Pharmacological Tools for the Correction of Gastrointestinal Motility Disorders

Abstract:

A recent bibliographic survey in three reputed pharmacology journals during 2007 indicated that gastrointestinal (GI) pharmacology is the leading fields of pharmacological research. This led to undertake a bibliographic search for various pharmacological tools in exploring the common mechanisms involved in GI motility, which would help in suggesting corrections for its deranged state. 5-HT tools: Peristaltic and secretory reflexes are initiated by submucosal intrinsic primary afferent neurons through 5-HT. Discovery of 5-HT receptor antagonists 3 (Ondansetron and granisetron) led to a major breakthrough in the control of chemotherapy-induced emesis. Cholinergic tools: Parasympathetic nervous system is the major one for maintaining normal intestinal motility by releasing acetylcholine (ACh) which stimulate cholinoceptors- muscarini (M) and nicotinic receptors. Contraction can also be induced by M receptor agonists (carbachol, oxotremorine) and with nicotinic agonists (nicotine, dimethylphenyl piperazinium iodide (DMPP)). These effects can be identified by muscarinic antagonists (atropine) and ganglionic blockers (mecamylamine). Tachykinin tools: TK antagonists (Aprepitant,SR140333) could counteract the most significant symptoms characterizing gut diseases. Nitric oxide(NO) tools: The gas, NO is considered as one of the important inhibitory mediators of non-adrenergic non-cholinergic (NANC) transmission in gut. Neuronal nitric oxide synthase inhibitors (Methyl arginine, nitroarginine) are used to identify NO actions. Vasoactive intestinal polypeptide (VIP) tools: VIP plays an important role in the mediation of NANC relaxation of smooth muscles and in inhibitory regulation of GI motility. ATP and its tools: ATP acts on purinergic receptors on intestinal smooth muscle and nerve endings that causes relaxation or contraction. Pyridylisatogen, a specific ATP antagonist blocks the relaxation induced by ATP in guinea pig taenia caeci.

KEYWORDS: Motor activity, Peristalsis, Scientometric study, Experimental tools.