Fura-2 used as a probe to show elevated intracellular free calcium in platelets of Dahl-sensitive rats fed a high salt diet.
Elevated intracellular free calcium concentration [Ca2+]i in vascular smooth muscle cells has been implicated in the pathophysiology of hypertension. Platelet [Ca2+]i was measured using the fluorescent indicator, Fura-2, in Dahl sensitive (DS) and resistant (DR) rats given high (8% NaCl) and low (0.4% NaCl) salt diets, as well as in the spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. The aim of this study was to show whether [Ca2+]i is elevated in salt induced hypertension. Platelet [Ca2+]i and systolic blood pressure (SBP) were higher (p less than 0.001) in DS rats given a high than low salt diets. In contrast, no changes in platelet [Ca2+]i and SBP were observed in DR rats. In SHR, platelet [Ca2+]i and SBP were higher (p less than 0.001) than in the WKY rats. Platelet [Ca2+]i correlated with SBP in all groups of rats (r = 0.929; p less than 0.001, n = 38). The parallel increase in SBP and [Ca2+]i in the DS high salt rats and the SHR suggests that an increased [Ca2+]i is involved in the pathophysiology of hypertension in the two models which differ with respect to the pathogenesis of their hypertension. This increase in [Ca2+]i therefore seems to reflect an abnormality in [Ca2+]i handling in hypertension regardless of its cause.
Vasdev
S
S
Disciplines of Medicine, Memorial University, St. John's, Newfoundland, Canada.
Thompson
P
P
Triggle
C
C
Fernandez
P
P
Bolli
P
P
Ananthanarayanan
V S
VS
D000818:Animals; D001572:Benzofurans; D001792:Blood Platelets / Q000187:drug effects / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D002118:Calcium / Q000097:blood*; D016257:Fura-2; D007700:Kinetics; D051381:Rats; D011918:Rats, Inbred SHR; D011919:Rats, Inbred Strains; D011921:Rats, Inbred WKY; D012982:Sodium, Dietary / Q000494:pharmacology*; D013045:Species Specificity; D013050:Spectrometry, Fluorescence
D001572:Benzofurans; D012982:Sodium, Dietary; D002118:Calcium; D016257:Fura-2