AIM: To study effects of hydrogen sulfide (H2S) on the carotid sinus baroreflex (CSB). METHODS: The functional curve of the carotid sinus baroreflex was measured by recording changes in arterial pressure in anesthetized male rats with perfused carotid sinus. RESULTS: H2S (derived from sodium hydrosulfide) at concentrations of 25, 50, and 100 micromol/L facilitated the CSB, shifting the functional curve of the baroreflex downward and to the left. There was a marked increase in peak slope (PS) and reflex decrease in blood pressure (RD). Effects were concentration-dependent. Pretreatment with glibenclamide (20 micromol/L), a K(ATP) channel blocker, abolished the above effects of H2S on CSB. Pretreatment with Bay K8644 (an agonist of calcium channels; 500 nmol/L) eliminated the effect of H2S on CSB. An inhibitor of cystathionine gamma-lyase (CSE), DL-propargylglycine (PPG; 200 micromol/L), inhibited CSB in male rats and shifted the functional curve of the baroreflex upward and to the right. CONCLUSION: These data suggest that exogenous H2S exerts a facilitatory role on isolated CSB through opening K(ATP) channels and further closing the calcium channels in vascular smooth muscle. Endogenous H2S may activate the activity of the CSB in vivo.
AIM: To study effects of hydrogen sulfide (H2S) on the carotid sinus baroreflex (CSB). METHODS: The functional curve of the carotid sinus baroreflex was measured by recording changes in arterial pressure in anesthetized male rats with perfused carotid sinus. RESULTS:H2S (derived from sodium hydrosulfide) at concentrations of 25, 50, and 100 micromol/L facilitated the CSB, shifting the functional curve of the baroreflex downward and to the left. There was a marked increase in peak slope (PS) and reflex decrease in blood pressure (RD). Effects were concentration-dependent. Pretreatment with glibenclamide (20 micromol/L), a K(ATP) channel blocker, abolished the above effects of H2S on CSB. Pretreatment with Bay K8644 (an agonist of calcium channels; 500 nmol/L) eliminated the effect of H2S on CSB. An inhibitor of cystathionine gamma-lyase (CSE), DL-propargylglycine (PPG; 200 micromol/L), inhibited CSB in male rats and shifted the functional curve of the baroreflex upward and to the right. CONCLUSION: These data suggest that exogenous H2S exerts a facilitatory role on isolated CSB through opening K(ATP) channels and further closing the calcium channels in vascular smooth muscle. Endogenous H2S may activate the activity of the CSB in vivo.
Authors: Daniel Yoo; Ryan C Jupiter; Edward A Pankey; Vishwaradh G Reddy; Justin A Edward; Kevin W Swan; Taylor C Peak; Ricardo Mostany; Philip J Kadowitz Journal: Am J Physiol Heart Circ Physiol Date: 2015-06-12 Impact factor: 4.733
Authors: Trenton D Colburn; Clark T Holdsworth; Jesse C Craig; Daniel M Hirai; Shawnee Montgomery; David C Poole; Timothy I Musch; Michael J Kenney Journal: Respir Physiol Neurobiol Date: 2020-04-21 Impact factor: 1.931