VASA. Zeitschrift fur Gefasskrankheiten · 1999
Early and late functional and histopathological perturbations in the rabbit ear-artery following local cold injury.
СтатьяНазвание и аннотация: Перевод пока не подготовлен
Обработка статьи · этапы, ошибки и управление
Загрузка состояния…
Ошибки и ограничения
История · было → стало
Состояние обновляется каждые 5 секунд, пока блок открыт. Процент показывается только там, где известен объём работы. Пауза останавливает продолжение этапа; текущий запрос к источнику может завершиться.
Arvesen A, Maehlen J, Rosén L, Aas P
Аннотация
BACKGROUND: These experiments aimed to study the in vivo short and long term neurovascular regeneration after frostbite.
METHODS: The rabbit central ear-artery was used as the experimental model. The effects on the noradrenergic innervation of the artery were measured in isolated vascular ring segments the first day and 2, 3-4, and 8-10 or 10-20 weeks following freezing at -9 degrees C or -18 degrees C for 15 min with slow rewarming for 7 min at room temperature.
RESULTS: Two days after freezing the sympathetic nerves were completely degenerated, as observed with glyoxylic acid-induced fluorescence. The vascular isometric tension responses to exogenous noradrenaline and endogenously released noradrenaline by electrical stimulation in vitro were abolished. A varying degree of necrosis of the vascular wall was observed. Two weeks after freezing at -18 degrees C in vitro responses to exogenous noradrenaline and electrical stimulation were still abolished, then gradually approaching control levels after 10-20 weeks of in vivo regeneration. Eight and 10 weeks after injury at -9 degrees C increased vascular tension responses to exogenous noradrenaline was found. In spite of a long regeneration period the total uptake and the spontaneous and K+ (75 mM) evoked releases of [3H]noradrenaline were persistently decreased after frostbite at -18 degrees C, but they were regenerated to control levels already 10-20 weeks after -9 degrees C. Regeneration of noradrenergic nerve function, expressed as [3H]noradrenaline uptake and release and responsiveness to electrical stimulation, expressed as vascular contraction, was slower than the regeneration of the vascular smooth muscle. Myointimal hyperplasia developed in response to -9 degrees C and -18 degrees C frostbite. The uptake and the K+ evoked release of [3H]noradrenaline were particularly sensitive parameters for autonomic nerve function.
CONCLUSIONS: The present findings may demonstrate important neurovascular reactions to local frostbite and may explain human sequelae following frostbite.
METHODS: The rabbit central ear-artery was used as the experimental model. The effects on the noradrenergic innervation of the artery were measured in isolated vascular ring segments the first day and 2, 3-4, and 8-10 or 10-20 weeks following freezing at -9 degrees C or -18 degrees C for 15 min with slow rewarming for 7 min at room temperature.
RESULTS: Two days after freezing the sympathetic nerves were completely degenerated, as observed with glyoxylic acid-induced fluorescence. The vascular isometric tension responses to exogenous noradrenaline and endogenously released noradrenaline by electrical stimulation in vitro were abolished. A varying degree of necrosis of the vascular wall was observed. Two weeks after freezing at -18 degrees C in vitro responses to exogenous noradrenaline and electrical stimulation were still abolished, then gradually approaching control levels after 10-20 weeks of in vivo regeneration. Eight and 10 weeks after injury at -9 degrees C increased vascular tension responses to exogenous noradrenaline was found. In spite of a long regeneration period the total uptake and the spontaneous and K+ (75 mM) evoked releases of [3H]noradrenaline were persistently decreased after frostbite at -18 degrees C, but they were regenerated to control levels already 10-20 weeks after -9 degrees C. Regeneration of noradrenergic nerve function, expressed as [3H]noradrenaline uptake and release and responsiveness to electrical stimulation, expressed as vascular contraction, was slower than the regeneration of the vascular smooth muscle. Myointimal hyperplasia developed in response to -9 degrees C and -18 degrees C frostbite. The uptake and the K+ evoked release of [3H]noradrenaline were particularly sensitive parameters for autonomic nerve function.
CONCLUSIONS: The present findings may demonstrate important neurovascular reactions to local frostbite and may explain human sequelae following frostbite.