The effects of short-term nifedipine treatment on responsiveness of aortic rings of cadmium-hypertensive rats.
The effects of short-term antihypertensive treatment with nifedipine on blood pressure and vascular responsiveness were studied in cadmium-hypertensive and normotensive control rats. Cadmium administration caused a significant increase in mean arterial blood pressure. Endothelin-1, noradrenaline and angiotensin II produced concentration dependent contractions of aortic rings that attained a lower maximal contraction in cadmium-hypertensive rats. Responses of aortic rings to KCl did not show a significant difference between the groups. Nifedipine administered simultaneously with cadmium inhibited the induction of hypertension. Nifedipine treatment for 5 days significantly reduced the blood pressure in cadmium-hypertensive and normotensive rats. Neither inhibition of hypertension nor normalization of blood pressure in cadmium-hypertensive rats caused an alteration in contractile responses of aortic rings to vasoconstrictors which suggested that development of decreased vascular reactivity and of hypertension occurs simultaneously in cadmium-hypertensive rats but the role of decreased vascular reactivity in maintenance of hypertension is questionable in cadmium-hypertension.
Ozdem
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SS
Department of Pharmacology, Medical Faculty of Akdeniz University, Antalya, Turkey. ozdem@hipokrat.med.akdeniz.edu.tr
Oğütman
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C
D000109:Acetylcholine / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000503:physiopathology*; D001794:Blood Pressure / Q000187:drug effects; D019256:Cadmium Chloride / Q000037:antagonists & inhibitors / Q000633:toxicity*; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D004195:Disease Models, Animal; D019332:Endothelin-1 / Q000494:pharmacology; D005500:Follow-Up Studies; D006973:Hypertension / Q000139:chemically induced / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D009543:Nifedipine / Q000627:therapeutic use*; D009638:Norepinephrine / Q000494:pharmacology; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D002121:Calcium Channel Blockers; D019332:Endothelin-1; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D000804:Angiotensin II; D009543:Nifedipine; D019256:Cadmium Chloride; D000109:Acetylcholine; D009638:Norepinephrine