Comparison of ryanodine binding to cardiac sarcoplasmic reticulum and nuclear envelope of rat.
- Author:
Pei-Yong WANG
1
;
Jun YANG
;
Lin-Wang DONG
;
Yong-Zheng PANG
;
Chao-Shu TANG
Author Information
- Publication Type:Journal Article
- MeSH: Animals; Calcium; metabolism; Kinetics; Myocardium; metabolism; Nuclear Envelope; metabolism; physiology; Phosphorylation; Rats; Rats, Sprague-Dawley; Ryanodine; metabolism; Ryanodine Receptor Calcium Release Channel; metabolism; Sarcoplasmic Reticulum; metabolism; physiology
- From: Chinese Journal of Applied Physiology 2002;18(1):43-46
- CountryChina
- Language:Chinese
-
Abstract:
AIMThe characteristics of ryanodine receptor in rat cardiac sarcoplasmic reticulum (SR) and nuclear envelope (NE) were studied.
METHODSVelocity and isopyknic gradient centrifugation was employed to fractionate rat SR and NE. Ryanodine receptor was assayed with [3H] ryanodine saturate binding to the preparations.
RESULTSThe maximal binding (Bmax) and dissociating constant (Kd) of ryanodine receptor in rat cardiac NE were, 1.7% and 60% of those in SR respectively. Phosphorylation in vitro by PKA and PKC increased Bmax of the receptors in SR by 372% and 121%, and augmented those in NE by 221% and 306%, without any effects on Kd.
CONCLUSIONRyanodine receptors were present in rat myocardial NE, with lower density and higher affinity than those located in SR, which can be activated by PKA and PKC.
