Effects of dietary salt and angiotensin-converting enzyme inhibitor on ATP-driven Ca pump and Na/Ca exchange in aortic rings of Dahl rats.
We examined effects of dietary salt and cilazapril on ATP-driven Ca pump and Na/Ca exchange system in arterial smooth muscle of Dahl salt-sensitive (DS) rats. Twenty-four DS rats were assigned to 4 groups. H- and H+ rats were fed a high-salt diet. L- and L+ rats were fed a low-salt diet. H+ and L+ were administered cilazapril. Aortic rings were superfused with physiological saline, and isometric tension was measured. Relaxation rates of low-Na(+)-induced contractions were promoted by the removal of external Ca. Cilazapril significantly decreased blood pressure in both the high- and low-salt diet groups. Salt loading reduced relaxation rates in 1.2 mmol/l Na+, and enhanced the increase in relaxation rates from 1.2 mmol/l to normal Na+. A negative correlation was observed between Ca extrusion by the Ca pump and blood pressure, and a positive correlation was observed between Ca extrusion by Na/Ca exchange and blood pressure. The results suggest that the decrease of Ca2+ extrusion by the ATP-driven Ca pump resulting from a high-salt diet might lead to an elevation in the concentration of cellular Ca2+.
Ashida
T
T
Division of Cardiovascular Diseases, Asahi Life Foundation, Tokyo, Japan.
Yoshimi
H
H
Kawano
Y
Y
Matsuoka
H
H
Omae
T
T
D000255:Adenosine Triphosphate / Q000378:metabolism; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects* / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D001835:Body Weight / Q000187:drug effects; D002110:Caffeine / Q000494:pharmacology; D000252:Calcium-Transporting ATPases / Q000187:drug effects* / Q000378:metabolism*; D017315:Cilazapril / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006973:Hypertension / Q000209:etiology; D066298:In Vitro Techniques; D017136:Ion Transport / Q000187:drug effects; D007668:Kidney / Q000187:drug effects; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000378:metabolism; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology; D012964:Sodium / Q000378:metabolism*; D012982:Sodium, Dietary / Q000008:administration & dosage*; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology; D014664:Vasodilation / Q000187:drug effects / Q000502:physiology
D000806:Angiotensin-Converting Enzyme Inhibitors; D012982:Sodium, Dietary; D017315:Cilazapril; D002110:Caffeine; D000255:Adenosine Triphosphate; D012964:Sodium; D000252:Calcium-Transporting ATPases