Effect of pinealectomy and exogenous melatonin administration on jejunal melatonin level
RAKESH THAKUR, J.S. TYAGI, J. MOHAN AND K.V.H. SASTRY
Division of Physiology and Reproduction
Central Avian Research Institute Izatnagar - 243 122(UP)
Melatonin a biomolecule synthesized from tryptophan is present in gastrointestinal tract in significant quantities but the factors affecting its level in gut tissue (especially in avian species are not yet ascertained. An attempt has been made in this study to elucidate the effect of pinealectomy and exogenous melatonin administration on jejunal melatonin level in broiler chicken. 144 day old chicks were divided into three groups i.e. control, sham operated and pinealectomised and kept under continuous light with standard management conditions. Half of birds from each group were supplemented with exogenous melatonin @ 5ppm while the other half received a placebo up to 20 days. Experimental birds were sacrificed at day 1, 10 and 20 to collect jejunum. Melatonin level in jejunal tissue was estimated using reverse phase HPLC. Results indicated that pinealectomy did not produce any significant variation in jejunal melatonin level while exogenous administration significantly increased (P<0.05) gut melatonin level suggesting that during photo phase most of melatonin present in gut is of local origin and not of pineal origin but it has a tendency to accumulate melatonin from systemic circulation.