Barker J A, Chediak A D, Baier H J, Wanner A
Department of Medicine, University of Miami at Mount Sinai Medical Center, Miami Beach, Florida 33140.
J Appl Physiol (1985). 1988 Aug;65(2):829-34. doi: 10.1152/jappl.1988.65.2.829.
In lightly anesthetized adult sheep, we determined tracheal mucosal blood flow (Qtr) by measuring the steady-state uptake of dimethyl ether from a tracheal chamber created by an endotracheal tube provided with two cuffs. Qtr normalized for carotid arterial pressure [Qtr(n)] was determined before and after the exposure of the tracheal mucosa to aerosolized phenylephrine (0.25-2.0 mg), isoproterenol (0.05-0.8 mg), and methacholine (2.5-20 mg). The same doses of methacholine were also administered during the intravenous infusion of vasopressin. The measurements were repeated after intravenous pretreatment with the respective antagonists phentolamine, propranolol, and atropine. Mean +/- SE base-line Qtr(n) was 1.2 +/- 0.1 ml.min-1.mmHg-1.10(2). The autonomic antagonists had no effect on mean Qtr(n). Phenylephrine produced a dose-dependent decrease in mean Qtr(n) (-70% at the highest dose), which was blunted by phentolamine, and isoproterenol produced a dose-dependent increase in mean Qtr(n) (40% at the highest dose), which was blocked by propranolol. Methacholine failed to alter mean Qtr(n) even when Qtr was first decreased by vasopressin. We conclude that in lightly anesthetized adult sheep 1) base-line Qtr(n) is not under adrenergic or cholinergic control, 2) a locally administered alpha-adrenergic agonist decreases and beta-adrenergic agonist increases Qtr(n) via specific receptor activation, and 3) a locally administered cholinergic muscarinic agonist has no effect on Qtr(n).
在轻度麻醉的成年绵羊中，我们通过测量由带有两个袖带的气管内导管形成的气管腔内二甲醚的稳态摄取量来测定气管黏膜血流量（Qtr）。在气管黏膜暴露于雾化去氧肾上腺素（0.25 - 2.0毫克）、异丙肾上腺素（0.05 - 0.8毫克）和乙酰甲胆碱（2.5 - 20毫克）之前和之后，测定以颈动脉压归一化的Qtr[Qtr(n)]。在静脉输注血管加压素期间也给予相同剂量的乙酰甲胆碱。在用相应的拮抗剂酚妥拉明、普萘洛尔和阿托品进行静脉预处理后重复测量。平均±标准误基线Qtr(n)为1.2±0.1毫升·分钟-1·毫米汞柱-1·10(2)。自主拮抗剂对平均Qtr(n)无影响。去氧肾上腺素使平均Qtr(n)呈剂量依赖性降低（最高剂量时降低70%），这被酚妥拉明减弱，而异丙肾上腺素使平均Qtr(n)呈剂量依赖性增加（最高剂量时增加40%），这被普萘洛尔阻断。即使Qtr首先被血管加压素降低，乙酰甲胆碱也未能改变平均Qtr(n)。我们得出结论，在轻度麻醉的成年绵羊中：1）基线Qtr(n)不受肾上腺素能或胆碱能控制；2）局部给予α-肾上腺素能激动剂通过特异性受体激活降低Qtr(n)，β-肾上腺素能激动剂增加Qtr(n)；3）局部给予胆碱能毒蕈碱激动剂对Qtr(n)无影响。
