RESUMO
Objective:The aim of this study was to observe the role of NO in the action of tetramethylpyrazine (TMP) on arterioles vasomotion induced by noradrenaline (NA), in order to make further understand of vasodilation mechanism of TMP.Methods: Albino rabbits weighting 2.0 ～ 2.5 kg were anesthetized. They were ventilated with room air via tracheotomy tube. The arterial pressure was monitored with a pressure transducer attached to a polyethylene canula in the right common carotid artery by four channel polygraph, the intestinal loop was mounted on the stage of an inverted microscope and bathed in balanced Kreb Ringer solution maintained at 37.5 ?C . The inside diameter of arterioles were measured manully on a TV monitor using a TV camera mounted on the microscope. Observe the changes of BP、 microcirculation and filtration of true capillary after injection of TMP 8mg/kg、 N G monomethyl L arginine( L NMMA) 10mg via a cannula in the left carotid artery after topical application of NA(0.8?g) conducted in the measured field. Results:TMP can inhibit spontaneous vasomotion in vasodilation; L NMMA can inhibit it in vasoconstriction stage. L NMMA have no effect on the action of TMP. Conclusions: Endogenous NO has no role in TMP's vasodilation.
RESUMO
AIM AND METHODS: To explore the effects calcitonin gene-related peptide (CGRP) and endothelin-1(ET-1) on the mechanisms of hypoxic pulmonary hypertension (HPH),the contents of CGRP and ET-1 in plasma of pulmonary artery and thoracic aorta and in extractives of lung and ventricular tissues of the chronic hypoxic rats were determined by radioimmunoassay. The changes of their hemodynamic indices and right heart hypertrophy index were monitored simultaneously. RESULTS: The level of pulmonary artery plasma CGRP was significantly higher than that of thoracic aorta plasma,but just the reverse was ET-1 or the ratio of ET-1 and CGRP in control rats( P