Mahe L, Chapelain B, Gargouil Y M, Neliat G
CEREP, Celle l'Evescault, France.
Eur J Pharmacol. 1991 Jun 18;199(1):19-25. doi: 10.1016/0014-2999(91)90632-z.
The pharmacological characterization of beta-adrenoceptor subtypes and the identification of two cell populations were investigated in isolated bovine mesenteric lymphatic vessels. The beta-adrenoceptor agonists isoprenaline, dobutamine and salbutamol concentration dependently decreased the amplitude and the frequency of spontaneous contractions and the amplitude of electrically induced contractions. The order of potency was isoprenaline greater than salbutamol greater than dobutamine. These effects were competitively antagonized by atenolol with pA2 values close to 7 with isoprenaline and dobutamine as agonists, and near 5.5 with salbutamol as the agonist. Noradrenaline concentration dependently reduced electrically induced contractions, an effect which was reversed to a slight enhancement after blockade of beta-adrenoceptors with propranolol (10(-6) M). These results confirmed the presence of postjunctional beta 1- and beta 2-adrenoceptor subtypes in lymphatic vessels and provide the first indication of the existence of two pharmacologically and functionally distinct cell populations, one of which exhibits pacemaker activity.
在分离的牛肠系膜淋巴管中研究了β-肾上腺素能受体亚型的药理学特性，并鉴定了两种细胞群。β-肾上腺素能受体激动剂异丙肾上腺素、多巴酚丁胺和沙丁胺醇浓度依赖性地降低了自发收缩的幅度和频率以及电诱导收缩的幅度。效价顺序为异丙肾上腺素＞沙丁胺醇＞多巴酚丁胺。阿替洛尔竞争性拮抗这些作用，以异丙肾上腺素和多巴酚丁胺为激动剂时pA2值接近7，以沙丁胺醇为激动剂时接近5.5。去甲肾上腺素浓度依赖性地降低电诱导收缩，在用普萘洛尔（10⁻⁶ M）阻断β-肾上腺素能受体后，这种作用逆转至轻微增强。这些结果证实了淋巴管中存在节后β1和β2肾上腺素能受体亚型，并首次表明存在两种药理学和功能上不同的细胞群，其中一种表现出起搏活动。
