Effects of Sympathetic Dertervation and Dexamethasoneon Pial Microvascular Pressures of Acute Hypoxic Rabbits
- VernacularTitle:去交感神经支配和地塞米松对急性缺氧家兔软脑膜微血管压的影响
- Author:
Yiyang XIA
- Publication Type:Journal Article
- Keywords:
Anoxia/physiopathology;
Cerebrovascuiar circulation/drug effects;
Denervation;
Dexamethasone/pbarmacodynamics
- From:Journal of Third Military Medical University
1983;0(04):-
- CountryChina
- Language:Chinese
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Abstract:
To determine the effects of sympathetic denervation and dexamethasone on the individual cerebrovascular pressure profile during hypoxia, we measured pial mi-crovascular pressure in 24 anesthetized rabbits with a servo-null system. At simulated altitude of 4,000m, the mean pressure in pial arterioles (50 to 70 ?m in diam) of acute hypoxia group decreased significantly. Pressure drop of upstream to downstream ratio of micropressure measured arterioles markedly increased. Internal carotid blood flow aimost doubled. Piai arterioiar pressures of both de-nervated group and dexamethasone group were significantly higher than the value of acute hypoxia group, but were not different from the pre-hypoxic values. Upstream to downstream pressure drop ratio of denervated group and dexamethasone group did not change significantly, but was much lower than the vauie of acute hypoxia group. The results indicates ①sympathetic nerves and dexamethasone have no effect on longitudinal distribution of cerebro-vascular pressure in rabbits during normoxia, normocapnia and normotension;②during hypoxia, pressure drop increases in upstream arteries of micropressure measured arterioles (50 to 70 ?m in diam) and/or decreases in downstream vessels partly due to activation of sympathetic nerves;③dexamethasone treatment can prevent the hypoxia induced longitudinal pressure redistribution in cerebral vessels, which may partly explain the action of dexamethasone on prevention and cure of acute mountain sickness.
