scholarly journals Smooth muscle cell expression of type I cyclic GMP-dependent protein kinase is suppressed by continuous exposure to nitrovasodilators, theophylline, cyclic GMP, and cyclic AMP.

1997 ◽  
Vol 100 (10) ◽  
pp. 2580-2587 ◽  
Author(s):  
G A Soff ◽  
T L Cornwell ◽  
D L Cundiff ◽  
S Gately ◽  
T M Lincoln
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase ◽  
Cyclic Amp ◽  
Smooth Muscle Cell ◽  
Cyclic Gmp ◽  
Type I ◽  
Continuous Exposure ◽  
Dependent Protein Kinase ◽  
Dependent Protein ◽  
Cell Expression

scholarly journals The amounts of rat liver cyclic AMP-dependent protein kinase I and II are differentially regulated by diet

1988 ◽  
Vol 256 (2) ◽  
pp. 447-452 ◽  
Author(s):  
R Ekanger ◽  
O K Vintermyr ◽  
S O Døskeland
Keyword(s):  
Protein Kinase ◽  
Cyclic Amp ◽  
Protein Restriction ◽  
Type I ◽  
Short Term ◽  
Rat Hepatocyte ◽  
Dependent Protein Kinase ◽  
Key Enzyme ◽  
Dependent Protein ◽  
Fasted Rats

1. The fluctuations in rat hepatocyte volume and protein content in response to dietary perturbations (starvation, protein restriction, refeeding) were accompanied by corresponding fluctuations in the amount of the regulatory (R) and catalytic (C) subunits of cyclic AMP-dependent protein kinase. Thus the intracellular concentration of this key enzyme was adjusted to be near constant. 2. The adjustment of cellular R was accomplished almost exclusively by regulating cytosolic RI (R subunit of type I kinase). The preferential down-regulation of cytosolic RI in response to starvation/protein restriction indicates that particulate RI and cytosolic as well as particulate RII are more resistant to breakdown during general catabolism in the hepatocyte. 3. The diet-induced fluctuations of kinase subunits were uniformly distributed in all populations of parenchymatous hepatocytes, regardless of their size and density. It is thus possible to isolate hepatocytes with uniformly altered RI/RII ratio from livers of rats with different feeding regimens. 4. The binding of endogenous cyclic AMP to RI and RII was similar in livers with high RI/RII ratio (fed rats) and low RI/RII ratio (fasted rats) as well as in hepatocytes isolated from fasted rats. Under the conditions of the experiment (short-term stimulation by glucagon), therefore, neither the dietary state nor the RI/RII ratio seemed to affect the apparent affinity of the isoreceptors for cyclic AMP. However, RI appeared to show a slightly higher co-operativity of intracellular cyclic AMP binding than did RII in all states.

Sign in / Sign up

Export Citation Format

Share Document