Hydrogen sulfide facilitates carotid sinus baroreflex in anesthetized rats.
OBJECTIVE
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.


CONCLUSIONS
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.
Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
Lin
L
Xiao
Yu-ming
YM
Wu
Hao
H
Zhang
Yi-xian
YX
Liu
Rui-rong
RR
He
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000480:Alkynes / Q000494:pharmacology; D000818:Animals; D017704:Baroreflex / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D002120:Calcium Channel Agonists / Q000494:pharmacology; D002346:Carotid Sinus / Q000187:drug effects / Q000502:physiology*; D003542:Cystathionine gamma-Lyase / Q000037:antagonists & inhibitors; D005905:Glyburide / Q000494:pharmacology; D005998:Glycine / Q000031:analogs & derivatives / Q000494:pharmacology; D006862:Hydrogen Sulfide / Q000494:pharmacology*; D008297:Male; D026902:Potassium Channel Blockers / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013440:Sulfides / Q000494:pharmacology
D000480:Alkynes; D002120:Calcium Channel Agonists; D026902:Potassium Channel Blockers; D013440:Sulfides; C009055:propargylglycine; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; D003542:Cystathionine gamma-Lyase; C025451:sodium bisulfide; D005905:Glyburide; D005998:Glycine; D006862:Hydrogen Sulfide