Pertussis toxin does not prevent alpha adrenergic stimulated breakdown of phosphoinositides or respiration in brown adipocytes

The role of Ni in mediation of alpha adrenergic stimulated respiration and breakdown of phosphatidylinositol 4,5-P 2 in brown adipocytes was examined using pertussis toxin. Phenylephrine stimulation of respiration and breakdown of PtdIns-4,5-P 2 was still present in adipocytes harvested from hamsters treated with pertussis toxin although toxin modification of Ni appeared complete as judged from the absence of incorporation of [ 32 P] from [ 32 P]-NAD into a 41 KD protein in membranes. These data suggest that alpha-1 receptors on brown adipocytes are not coupled to inositide hydrolysis through Ni.