Partially phosphorylated phosphorylase in the rat heart after β-receptor stimulation in vivo

Title:

Partially phosphorylated phosphorylase in the rat heart after β-receptor stimulation in vivo

Creator:

Kuželová-Belanová, M., Vereb, G., and Švec, P.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:67c6c08c-9a05-4130-a0b3-473e0750425a
uuid:67c6c08c-9a05-4130-a0b3-473e0750425a

Subject:

glycogen phosphorylase, phosphorylase ab hybrid, isoproterenol, protein phosphorylation, and rat heart

Type:

article, model:article, and TEXT

Description:

The formation of the phosphorylase ab hybrid and its further transformation into phosphorylase a has been demonstrated in the rat heart after different periods of i.v. isoproterenol administration. Phosphorylase ab hybrid was determined in the presence of AMP and/or caffeine. Only the partially phosphorylated phosphorylase was found in the control rat hearts and its activity was 30 % of the total phosphorylase. The phosphorylase ab hybrid was disclosed particularly after small isoproterenol doses (0.031 -0.062 /rg.kg-1) and at short time interval (15 s) after its administration. Higher isoproterenol doses (0.25-0.5 ¿/g.kg-1) changed the partially phosphorylated phosphorylase to phosphorylase a (58 %) after a longer time interval (40 s), The phosphorylase ab hybrid was revealed even at the maximal rate of stimulation. The formation of the phosphorylase ab hybrid in the rat heart in vivo appears to be of physiological significance. Our results confirmed the earlier suggestion that the -AMP/-f AMP activity ratio reflects the percentage proportion of the phosphorylated subunits of phosphorylase but not of the activated phosphorylase molecules.

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 1994 Volume:43 | Number:5

Harvested from:

CDK

Metadata only:

false