Characterization of the a1B-adrenergic receptors of chicken hepatocytes. Signal transduction and actions
Por:
Gutiérrez-Venegas G., García-Sáinz J.A.
Publicada:
1 ene 1993
Resumen:
1. In chicken hepatocytes, ?1-adrenoceptor activation increased: (a) phosphatidylinositol labeling; (b) production of inositol trisphosphate; (c) cytosol calcium; and (d) phosphorylase activity. 2. Prazosin (Ki ? 0.2-0.4 nM) was more potent in inhibiting these actions than 5-methyl-urapidil (Ki ? 30-60 nM); these actions were sensitive to chlorethylclonidine suggesting the involvement of ?1-adrenoceptors. 3. The stimulation of phosphoinositide turnover was insensitive to pertussis toxin. 4. In chicken liver membranes, [3H]prazosin binding sites (Bmax 872 fmol/mg protein) with high affinity for prazosin (KD 0.3 nM; Ki 0.4 nM) and lower affinity for 5-methyl-urapidil (Ki 46 nM) were detected, consistent with the presence of ?1B-adrenoceptors. © 1993.
Filiaciones:
Gutiérrez-Venegas G.:
Instituto de Fisiología Celular, Universidad National Autónoma de México, Apdo. Postal 70-248
García-Sáinz J.A.:
Instituto de Fisiología Celular, Universidad National Autónoma de México, Apdo. Postal 70-248