Cytosolic calcium in platelets of spontaneously hypertensive rats.
To test the hypothesis that an abnormality of the intracellular concentration of ionized calcium, [Ca2+]i, is associated with high blood pressure, we measured [Ca2+]i in the platelets of spontaneously hypertensive (SHR) and Wistar-Kyoto control (WKY) rats using the Quin 2 technique after separation of the platelets in calcium-free medium, during calcium repletion, and upon exposure to agonists which increase platelet [Ca2+]i (thrombin, adenosine diphosphate, serotonin and ionomycin). Despite clear-cut changes in [Ca2+]i during these manipulations, there were no differences between the SHR and WKY rats in baseline levels of [Ca2+]i or in the kinetics of changes in [Ca2+]i. These results do not support the hypothesis that high levels of [Ca2+]i at rest or abnormal kinetics of changes in [Ca2+]i play a pathophysiological role in the hypertension of SHR.
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000818:Animals; D001792:Blood Platelets / Q000032:analysis* / Q000187:drug effects; D001794:Blood Pressure; D002118:Calcium / Q000097:blood*; D003600:Cytosol / Q000032:analysis* / Q000187:drug effects; D004987:Ethers / Q000494:pharmacology; D006973:Hypertension / Q000378:metabolism*; D015759:Ionomycin; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D012701:Serotonin / Q000494:pharmacology; D013917:Thrombin / Q000494:pharmacology
D004987:Ethers; D012701:Serotonin; D015759:Ionomycin; D000244:Adenosine Diphosphate; D013917:Thrombin; D002118:Calcium