Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Stevioside is a sweet-tasting glycoside occurring abundantly in the leaves of Stevia rebaudiana (Compositae). It has been used popularly in Japan and Brazil as a sugar substitute for decades. Previous study has shown that it lowered blood pressure in spontaneously hypertensive rats (SHRs) when administered intravenously. This study shows that intraperitoneal injection of stevioside 25 mg/kg also has antihypertensive effect in SHRs. In isolated aortic rings from normal rats, stevioside could dose-dependently relax the vasopressin-induced vasoconstriction in both the presence and absence of endothelium. However, stevioside had no effect on phenylephrine- and KCl-induced phasic vasoconstriction. In addition, stevioside lost its influence on vasopressin-induced vasoconstriction in Ca(2+)-free medium. The results indicate that stevioside caused vasorelaxation via an inhibition of Ca(2+) influx into the blood vessel. This phenomenon was further confirmed in cultured aortic smooth muscle cells (A7r5). Using 10(-5) M methylene blue for 15 min, stevioside could still relax 10(-8) M vasopressin-induced vasoconstriction in isolated rat aortic rings, showing that this vasorelaxation effect was not related to nitric oxide. The present data show that the vasorelexation effect of stevioside was mediated mainly through Ca(2+) influx inhibition.
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PMID:Inhibitory effect of stevioside on calcium influx to produce antihypertension. 1174 13

Stevioside is a sweet-tasting glycoside isolated from the leaves of Stevia rebaudiana. It has been used as a noncaloric sugar substitute in Japan and Brazil for decades. Previous studies have shown that it lowered blood pressure in spontaneously hypertensive rats by intravenous injection. This study was designed to evaluate the hypotensive effect of stevioside in dogs and to define the underlying mechanism. After nasogastric administration of stevioside powder (200 mg/kg), the blood pressure of healthy mongrel dogs began to significantly decrease at 60 min and returned to baseline level at 180 min. The reduction of blood pressure was more rapid (at 5-10 min) and effective after intravenous injection. However, no significant change of blood pressure was noted after injection through left vertebral artery, implicating that the hypotensive effect is not related to the central nervous system. Stevioside also showed significant hypotensive effects in renal hypertensive dogs, in a dose-dependent manner. In cultured rat aortic smooth muscle cells (A7r5 cell line), stevioside can dose-dependently inhibit the stimulatory effects of vasopressin and phenylephrine on intracellular Ca(2+) in a calcium-containing medium. However, no intracellular Ca(2+) inhibitory effect was observed in calcium-free medium, implicating that stevioside may inhibit the Ca(2+) influx from extracellular fluid. Our present data show that stevioside did not influence the calcium ionophore (A23187) induced Ca(2+) influx, indicating that the antagonistic effect was through Ca(2+) channels. This study confirmed that stevioside is an effective antihypertensive natural product, and its hypotensive mechanism may be probably due to inhibition of the Ca(2+) influx.
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PMID:Mechanism of the antihypertensive effect of stevioside in anesthetized dogs. 1244 99