文章文围绕α1-肾上腺素受体的纯化及制备展开研究,将细胞经复苏后,以含有抗生素200μg/m L G418和10%FBS的DMEM溶液为培养液,在37℃和5%CO2的培养箱培养,获得大量α1-AR高表达细胞,并获得该受体,与文献通过亲和色谱法得到的该受体相比...文章文围绕α1-肾上腺素受体的纯化及制备展开研究,将细胞经复苏后,以含有抗生素200μg/m L G418和10%FBS的DMEM溶液为培养液,在37℃和5%CO2的培养箱培养,获得大量α1-AR高表达细胞,并获得该受体,与文献通过亲和色谱法得到的该受体相比,具有纯度高、省时、省力的特点,能为后续的受体生物色谱模型的建立提供有利的保障,并且为进一步采用亲和色谱法进行受体纯化提供了足量的细胞。展开更多
Clonidine is a classically categorized α2-adrenoceptor (α2-AR) agonist that produces vascular contractions by stimulating arterial smooth muscle α2-ARs. However, clonidine inhibits α1-AR-mediated arterial contract...Clonidine is a classically categorized α2-adrenoceptor (α2-AR) agonist that produces vascular contractions by stimulating arterial smooth muscle α2-ARs. However, clonidine inhibits α1-AR-mediated arterial contractions. Recently, it was suggested that repeated stimulation with clonidine induces desensitization of α2-ARs, thus inhibiting noradrenaline-induced smooth muscle contractions. In the present study, we examined whether clonidine-mediated inhibition of α1-AR contractions involves interactions with α2-ARs in rat thoracic aortae. 1) Clonidine and guanfacine inhibited electrical field stimulation-induced contractions in a concentration-dependent, yohimbine-sensitive manner in isolated rat vas deferens preparations. 2) Clonidine almost completely suppressed phenylephrine-induced sustained contractions of rat thoracic aortae. 3) Clonidine competitively inhibited phenylephrine-induced contractions with a pA2 value of 6.77 at concentrations between 10-7 and 10-6 M. At 10-5 M, clonidine inhibited phenylephrine-induced contractions and dramatically reduced maximum contractions. 4) In contrast, clonidine did not inhibit contractions produced by high KCl or prostaglandin F2α. 5) Inhibition of phenylephrine-induced sustained contractions by clonidine was also produced in the presence of yohimbine. However, guanfacine did not inhibit phenylephrine-induced sustained contractions. These findings suggest that clonidine inhibits phenylephrine-induced contraction of rat thoracic aortae by competitive antagonism of α1-ARs, which is mediated through a mechanism independent of α2-AR stimulation.展开更多
文摘文章文围绕α1-肾上腺素受体的纯化及制备展开研究,将细胞经复苏后,以含有抗生素200μg/m L G418和10%FBS的DMEM溶液为培养液,在37℃和5%CO2的培养箱培养,获得大量α1-AR高表达细胞,并获得该受体,与文献通过亲和色谱法得到的该受体相比,具有纯度高、省时、省力的特点,能为后续的受体生物色谱模型的建立提供有利的保障,并且为进一步采用亲和色谱法进行受体纯化提供了足量的细胞。
文摘Clonidine is a classically categorized α2-adrenoceptor (α2-AR) agonist that produces vascular contractions by stimulating arterial smooth muscle α2-ARs. However, clonidine inhibits α1-AR-mediated arterial contractions. Recently, it was suggested that repeated stimulation with clonidine induces desensitization of α2-ARs, thus inhibiting noradrenaline-induced smooth muscle contractions. In the present study, we examined whether clonidine-mediated inhibition of α1-AR contractions involves interactions with α2-ARs in rat thoracic aortae. 1) Clonidine and guanfacine inhibited electrical field stimulation-induced contractions in a concentration-dependent, yohimbine-sensitive manner in isolated rat vas deferens preparations. 2) Clonidine almost completely suppressed phenylephrine-induced sustained contractions of rat thoracic aortae. 3) Clonidine competitively inhibited phenylephrine-induced contractions with a pA2 value of 6.77 at concentrations between 10-7 and 10-6 M. At 10-5 M, clonidine inhibited phenylephrine-induced contractions and dramatically reduced maximum contractions. 4) In contrast, clonidine did not inhibit contractions produced by high KCl or prostaglandin F2α. 5) Inhibition of phenylephrine-induced sustained contractions by clonidine was also produced in the presence of yohimbine. However, guanfacine did not inhibit phenylephrine-induced sustained contractions. These findings suggest that clonidine inhibits phenylephrine-induced contraction of rat thoracic aortae by competitive antagonism of α1-ARs, which is mediated through a mechanism independent of α2-AR stimulation.
