Protease inhibitors potentiate smooth muscle relaxation induced by vasoactive intestinal peptide in isolated human bronchi.
Protease inhibitors potentiate smooth muscle relaxation induced by vasoactive intestinal peptide in isolated human bronchi.
复制标题
蛋白酶抑制剂增强离体人支气管中血管活性肠肽诱导的平滑肌松弛。
DOI:
10.1165/ajrcmb/2.5.449
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发表时间:
1990
影响因子:
6.4
通讯作者:
Caughey,GH
中科院分区:
文献类型:
--
作者:
Tam,EK;Franconi,GM;Nadel,JA;Caughey,GH
Materials and Methods Lung tissue was obtained from five nonsmoking patients 11 to 35 yr old undergoing heart-lung transplantation for pulmonary hypertension, either primary or secondary to congenital heart disease. No subject had clinical evidence of airway disease, infection, or left-sided congestive heart failure. Chronic medications before transplantation included oxygen, furosemide, nitroglycerin, or potassium, but no corticosteroids. Twenty rings from intrapulmonary lobar and segmental bronchi were attached to strain gauges to record isometric tension and placed in chambers filled with Krebs-Henseleit solution at 37 C aerated with 5% CO2 in O2• Rings were stretched to a tension of 5 g, equilibrated for 15 min with a resting tension of 1 g, then contracted with acetylcholine (10-3 M) to determine the maximal contraction. The tissues were washed repeatedly until a resting tension of 1 g was achieved. They were then incubated with indomethacin (2 x 10-6 M; 30 min), propranolol (10-6 M; 15 min) and pyrilamine (10-5 M; 15 min) to block prostaglandin, adrenergic, and histamine type I effects. Carbamylcholine (10-6 to 10-5 M) was added to cause half-maximal contraction. When the active tension was stable for at least 5 min, the protease inhibitors phosphoramidon, leupeptin, aprotinin, and soybean trypsin inhibitor (each 20 Itg/ml) were added to nine of the organ baths. Ten minutes later, VIP (5 x 10-7 M) was added to all organ baths, and the change in tension was recorded for at least 30 min. Tension was expressed as the percentage of the carbamylcholine-induced (active) tension measured immediately before the addition of VIP. Tissues that had not been treated with inhibitors and that had maintained or regained nearly 100% of active tension despite VIP were then treated with the protease inhibitors. These tissues included two consecutive segments of bronchus from which the epithelium had been removed. Responses to VIP and protease inhibitors were recorded for at