Effects of Azelastine and Sodium cromoglycate in the inhibition of Broncho - Constriction of ovalbumin sensitized Lung Parenchymal Tissues of Guinea Pigs in Vitro

ABSTRACT

To see the ability of Azelastine and Sodium cromoglycate in influencing antigen induced contractile responses in isolated parenchymal tissues of Guinea pig in vitro. An experimental study. Department of Pharmacology and Therapeutics of Basic Medical Sciences Institute, Jinnah Postgraduate Medical Center [JPMC], Karachi during 1998. The Guinea pigs [n=10] were sensitized with ovalbumin and their parenchymal strips were exposed to different concentrations of ovalbumin to observe the EC50. Each sensitized parenchymal strip was treated with either Azelastine or Sodium cromoglycte in an organ bath for 10 minutes and treated with EC50 ovalbumin and contraction was recorded by Grass Polygraph model 7B. EC50 [n=6] of parenchymal strips [0.3x10-6 + 0.16x10-6g/ml] produced a mean response of contraction 9+0.44mm. Azelastine in concentration of 10-9 g/ml did not show any inhibitory effect but as the concentration increased to 10-8 g/ml, marked inhibition was recorded and with further increase in concentration by 10-7 g/ml, it completely antagonized the EC50 induced contraction. Sodium cromoglycate did not show any inhibition at concentration 10-8 g/ml while at higher concentration of 10-6 g/ml, it showed complete antagonism. Ovalbumin induced contraction of sensitized lung parenchymal tissues of Guinea pig in vitro is dose dependent and controlled better with Azelastine than Sodium cromoglycate