title: Ginkgolide B inhibits carotid sinus baroreflex in anesthetized male rats.
abstract: The effects of ginkgolide B on the carotid sinus baroreflex (CSB) were studied in the perfused isolated carotid sinus of 30 anesthetized Sprague-Dawley male rats. The results were as follows. (1) By perfusing with ginkgolide B (0.1, 1, 10 μmol/L), the functional curve of the baroreflex was shifted to the right and upward. There was a marked decrease in peak slope (PS) and reflex decrease (RD) in mean arterial pressure (P<0.01), while the threshold pressure (TP), equilibrium pressure (EP) and saturation pressure (SP) were significantly increased (P<0.05, P<0.01). Among the functional parameters of CSB, the changes in PS, RD, TP, EP and SP were dose-dependent. (2) Pretreatment with Bay K8644 (500 nmol/L), an agonist of L-type calcium channel, completely eliminated the effects of ginkgolide B (1 μmol/L) on the CSB. (3) Pretreatment with tetraethylammonium (TEA, 1 mmol/L), an inhibitor of potassium channel, completely abolished the above effects of ginkgolide B (1 μmol/L) on the CSB. These results suggest that ginkgolide B inhibits the CSB in anesthetized rats, which is mediated by decreased calcium influx and increased potassium efflux in baroreceptor nerve endings.
authors.affiliation: Department of Physiology, Institute of Basic Medicine, Hebei Medical University, Shijiazhuang 050017, China.
authors.forename: Chun-Yan
authors.initials: CY
authors.lastname: Wang
authors.forename: Yu-Ming
authors.initials: YM
authors.lastname: Wu
authors.forename: Lin
authors.initials: L
authors.lastname: Xiao
authors.forename: Hong-Mei
authors.initials: HM
authors.lastname: Xue
authors.forename: Ru
authors.initials: R
authors.lastname: Wang
authors.forename: Fu-Wei
authors.initials: FW
authors.lastname: Wang
authors.forename: Rui-Rong
authors.initials: RR
authors.lastname: He
mesh_terms: D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000818:Animals; D017704:Baroreflex / Q000187:drug effects*; D002120:Calcium Channel Agonists / Q000494:pharmacology; D020746:Calcium Channels, L-Type; D002346:Carotid Sinus / Q000503:physiopathology*; D046934:Ginkgolides / Q000494:pharmacology*; D007783:Lactones / Q000494:pharmacology*; D008297:Male; D026902:Potassium Channel Blockers / Q000494:pharmacology; D011311:Pressoreceptors / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D019789:Tetraethylammonium / Q000494:pharmacology
chemical_list: D002120:Calcium Channel Agonists; D020746:Calcium Channels, L-Type; D046934:Ginkgolides; D007783:Lactones; D026902:Potassium Channel Blockers; D019789:Tetraethylammonium; D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C045856:ginkgolide B