Effect of sodium-potassium-dependent ATPase inhibition on noradrenaline-activated calcium sensitivity of mesenteric resistance vessels in adult spontaneously hypertensive rats.
1. We have investigated the noradrenaline-activated calcium sensitivity of 150 micrometer mesenteric resistance blood vessels from spontaneously hypertensive and control Wistar-Kyoto rats. 2. Under control conditions the spontaneously hypertensive rat blood vessels had a greater calcium sensitivity than the Wistar-Kyoto rat vessels. 3. In the presence of 1 mmol of ouabain/l, a treatment known to inhibit the sodium-potassium-dependent ATPase, the responses of the spontaneously hypertensive rat blood vessels were reduced more than those of the Wistar-Kyoto rat blood vessels, so that the responses of spontaneously hypertensive rat and Wistar-Kyoto rat blood vessels were then similar. 4. Similar results were obtained by removing external potassium, a procedure which should also inhibit the sodium-potassium-ATPase. 5. The results suggest that the greater noradrenaline-activated calcium sensitivity of spontaneously hypertensive rat blood vessels may be associated with an increased sodium-potassium-ATPase activity.
D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006973:Hypertension / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects / Q000503:physiopathology; D009119:Muscle Contraction / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000503:physiopathology*; D009638:Norepinephrine / Q000494:pharmacology; D010042:Ouabain / Q000494:pharmacology; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors / Q000378:metabolism*
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase; D002118:Calcium; D009638:Norepinephrine