K. KATHIRVEL, P.C.BEHERA, S. PALLAI, J. MOHANTY & S. C. PARIJA
Pharmacological and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) experiments were performed in goat ruminal artery to determine the pharmacological properties of á1?adrenoceptor present in goat ruminal artery. Ruminal artery was collected in chilled aerated modified?s Kreb?s Henseleit Solution (KHS) from local slaughter house and transported in ice to laboratory for further processing. The arterial ring was mounted in thermostatically controlled (37 ± 0.5 0C) automatic organ bath containing 20 ml of Modified KHS, bubbled with air (pH, 7.4) under 2g tension. The equilibration of 90 min was allowed after that drug was added. Nor-adrenaline (10 nM - 10 ìM) induced a concentration related contractile response with mean EC50 value of 0.73 ìM and pD2 value of 5.86 ± 0.05. Prazosin (0.01/ 0.1/ 1 nM), a nonselective á1-adrenoceptor antagonist caused a significant rightward shift of the NA-induced concentration-related response curve. The estimated pA2 for prazosin in this tissue was 10.9± 0.03. The RT-PCR analysis of mRNA of goat ruminal artery showed transcript for á1a/d-adrenoceptor. The present study proposed that the vasotonicity mediated by NA in goat ruminal artery is due to presence of á1a/d-adrenoceptor subtypes.
