AIM: To elucidate the role of NO in the effect of tetramethylpyrazine (TMP) on vasomotion of arterioles induced by noradrenalin(NA).METHODS: Albino rabbits were anesthetized,respiration were maintained,the arterial pressure were measured with a pressure transducer attached to a polyethylene canula in the left common carotid artery,the intestinal loop was mounted on the stage of an inverted microscope and bathed in balanced solution.The inside diameter of the arterial was manually measured on a TV monitor using the TV camera mounted on the microscope.RESULTS: Topical applicated NA to measured field inducd spontaneous vasomotion which has frequency and amplitude.TMP inhibited vasomotion in vasodilation. Treatment with L-NMMA did not affect the effect of TMP.CONCLUSION: L-NMMA can not inhibit action of TMP on vasomotion,TMP may act on smooth muscle directly, not through endogenous NO.

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.

With the continuously increasing demands of plastic products in the current society, the challenge of disposing plastic waste is constantly increasing, leading to the urgent need of mitigating plastic pollution. As a consequence, much attention has been paid to biodegradable plastics due to their degradability in a bio-active environment under certain conditions. Biodegradable plastics herald vast development potentials and considerable market prospects. The degradation of numerous types of biodegradable plastics will be affected by many factors. A thorough understanding of degradation mechanisms as well as functional microbial strains and enzymes is the key to comprehensive utilization and efficient treatment and disposal of biodegradable plastics. The article summarized the types, properties, advantages and disadvantages, and main applications of common biodegradable plastics. The degradation mechanisms, functional microbial strains and enzymes, as well as the degradation degree and duration under different environmental conditions, were also summarized. This review may help better understand the degradation of biodegradable plastics wastes.
Biodegradable Plastics ; Biodegradation, Environmental