title: Measurement of adenosine 3',5'-monophosphate-dependent protein kinase and phosphorylase activities in in vivo conditions.
abstract: Microassay procedures for cAMP-dependent protein kinase and phosphorylase were developed which detected these activities in less than 25 micrograms of frozen-dried epidermis from a punch biopsy of skin without homogenization. Using these procedures, the activation of cAMP-dependent protein kinase and phosphorylase by beta-adrenergic stimulation in mouse skin was studied in vivo. Cyclic AMP-dependent protein kinase was stimulated by isoproterenol and inhibited by propranolol. Isoproterenol stimulation also activated phosphorylase a in mouse skin. In normal epidermis and uninvolved and involved epidermis from psoriatic patients no significant differences were found in the activities of cAMP-dependent kinase and phosphorylase a. In all experiments we observed that the unstimulated activity ratios of phosphorylase a/total phosphorylase were around 20-30%; these values were much lower than those hitherto reported and show a preponderance of phosphorylase b rather than a. We suggest that in previous reports where phosphorylase a domination was found, phosphorylase b to a activation occurred during homogenization. The data also suggest that in the steady state no obvious defect in basic activities of cAMP-dependent protein kinase and phosphorylase is observed in psoriatic skin.
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism*; D004817:Epidermis / Q000201:enzymology*; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage; D051379:Mice; D008807:Mice, Inbred BALB C; D010762:Phosphorylase a / Q000032:analysis*; D010763:Phosphorylase b / Q000032:analysis; D006005:Phosphorylases / Q000032:analysis*; D011433:Propranolol / Q000008:administration & dosage; D047428:Protein Kinase Inhibitors; D011494:Protein Kinases / Q000032:analysis* / Q000096:biosynthesis; D011565:Psoriasis / Q000201:enzymology*; D012867:Skin / Q000201:enzymology*
chemical_list: D047428:Protein Kinase Inhibitors; D011433:Propranolol; D000242:Cyclic AMP; D010762:Phosphorylase a; D010763:Phosphorylase b; D006005:Phosphorylases; D011494:Protein Kinases; D007545:Isoproterenol