Immunoblot of Bax and Bcl-2 of the lung extracts of guinea pigs exposed to air or CS given water or BT as the drink. Panel A and Panel B depict respective immunoblots of Bax and Bcl-2. Lane 1, air-exposed guinea pigs given water; lane 2, CS-exposed guinea pigs given water; lane 3, air-exposed guinea pigs given BT; lane 4, CS-exposed guinea pigs given BT. In each case the membrane was reprobed with anti-mouse tubulin antibody to determine the level of tubulin as a loading control. Panel C shows the Bax/Bcl-2 ratio observed in different groups.