Na2S,a fast-releasing H2S donor,given as suppository lowers blood pressure in rats

Background hydrogen sulfide (h2s) is involved in blood pressure control. the available slow-releasing h2s-donors are poorly soluble in water and their ability to release h2s in biologically relevant amounts under physiological conditions is questionable. therefore,new slow-releasing donors or new experimental approaches to fast-releasing h2s donors are needed. methods hemodynamics and ecg were recorded in male,anesthetized wistar kyoto rats (wky) and in spontaneously hypertensive rats (shr) at baseline and after: 1) intravenous (iv) infusion of vehicle or na2s; 2) administration of vehicle suppositories or na2s suppositories. results intravenously administered vehicle and vehicle suppositories did not affect mean arterial blood pressure (mabp) and heart rate (hr). na2s administered iv caused a significant,but transient (2–5 min) decrease in mabp. na2s suppositories produced a dose-dependent hypotensive response that lasted ∼45 min in wky and ∼75–80 min in shr. it was accompanied by a decrease in hr in wky,and an increase in hr in shr. na2s suppositories did not produce a significant change in corrected qt,an indicator of cardiotoxicity. na2s suppositories increased blood level of thiosulfates,products of h2s oxidation. conclusions na2s administered in suppositories exerts a prolonged hypotensive effect in rats,with no apparent cardiotoxic effect. shr and wky differ in hemodynamic response to the h2s donor. suppository formulation of fast-releasing h2s donors may be useful in research,if a reference slow-releasing h2s donor is not available. © 2017 institute of pharmacology,polish academy of sciences