Independent vasomotor control of rat tail and proximal hairy skin
Independent vasomotor control of rat tail and proximal hairy skin
复制标题
大鼠尾部和近端毛状皮肤的独立血管舒缩控制
DOI：
10.1113/jphysiol.2007.131292
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
R. McAllen
中科院分区：
文献类型：
--
作者：
Mutsumi Tanaka;Y. Ootsuka;M. McKinley;R. McAllen
已知有毛和无毛皮肤的血管扩张控制之间存在数量差异，但尚不清楚它们是否受共同的中枢机制调节。我们对供应氨基甲酸乙酯麻醉、人工通气大鼠背部皮肤（有毛）和尾部（无毛）的交感皮肤血管收缩（CVC型）纤维进行了同步记录。剃去动物躯干毛，并将其包裹在灌注水的夹克中。尾部和背部皮肤CVC-型纤维都通过冷却躯干皮肤而被激活，并且独立于由此产生的核心（直肠）温度的下降，但它们的激活阈值不同（皮肤温度38.8 ± 0.4 ° C对36.8 ± 0.4°C，核心温度38.1 ± 0.2°C对36.8 ± 0.2 °C; P < 0.01）。背部皮肤CVC型纤维对皮肤的反应比对核心冷却的反应更大，而尾部纤维则相反。背部皮肤CVC型纤维对微注射到视前区的前列腺素E2（PGE 2）的反应低于尾纤维。光谱分析表明，在冷却过程中，尾部和背部皮肤CVC型纤维活动之间没有显著的一致性。视前PGE 2注射后，在1 Hz的相干峰出现在一些动物中，这消失后，相对于反射压力的偏置，表明这是由于共同的反射调制。通过显微注射蝇蕈醇（2 mm，60-120 nl）抑制了尾部和背部皮肤CVC-型纤维活动，并阻止了它们对随后皮肤冷却的反应。这些结果表明，无毛和有毛的皮肤血管的温度调节反应是由独立的神经通路控制，虽然都依赖于突触中继在延髓中缝。
Quantitative differences are known to exist between the vasomotor control of hairy and hairless skin, but it is unknown whether they are regulated by common central mechanisms. We made simultaneous recordings from sympathetic cutaneous vasoconstrictor (CVC‐type) fibres supplying back skin (hairy) and tail (hairless) in urethane‐anaesthetized, artificially ventilated rats. The animal's trunk was shaved and encased in a water‐perfused jacket. Both tail and back skin CVC‐type fibres were activated by cooling the trunk skin, and independently by the resultant fall in core (rectal) temperature, but their thresholds for activation differed (skin temperatures 38.8 ± 0.4°C versus 36.8 ± 0.4°C, core temperatures 38.1 ± 0.2°C versus 36.8 ± 0.2°C, respectively; P < 0.01). Back skin CVC‐type fibres were more responsive to skin than to core cooling, while the reverse applied to tail fibres. Back skin CVC‐type fibres were less responsive than tail fibres to prostaglandin E2 (PGE2) microinjected into the preoptic area. Spectral analysis showed no significant coherence between tail and back skin CVC‐type fibre activities during cooling. After preoptic PGE2 injection, a coherent peak at 1 Hz appeared in some animals; this disappeared after partialization with respect to ventilatory pressure, indicating that it was attributable to common ventilatory modulation. Neuronal inhibition in the rostral medullary raphé by microinjected muscimol (2 mm, 60–120 nl) suppressed both tail and back skin CVC‐type fibre activities, and prevented their responses to subsequent skin cooling. These results indicate that thermoregulatory responses of hairless and hairy skin vessels are controlled by independent neural pathways, although both depend on synaptic relays in the medullary raphé.