淡水龟（伪彩龟）的体温与脑血流量调节

Temperature and cerebral blood flow regulation in the freshwater turtle, Pseudemys scripta.

作者信息

Davies D G

机构信息

Department of Physiology, Texas Tech University Health Sciences Center, School of Medicine, Lubbock 79430.

出版信息

Respir Physiol. 1994 Mar;95(3):329-35. doi: 10.1016/0034-5687(94)90095-7.

DOI:10.1016/0034-5687(94)90095-7

PMID:8059076

Abstract

Chemical regulation of cerebral blood flow (CBF) by CO2 has been demonstrated in an ectohermic vertebrate (Davies, Am. J. Physiol. 260: R382, 1991). Cerebrovascular sensitivity to CO2 (delta CBF/delta PaCO2), a measure of the vascular reactivity of the cerebral blood vessels to CO2, was found to be 0.7 ml.min-1.100 g-1.Torr-1 during normoxia and 3.4 during anoxia in the freshwater turtle, Pseudemys scripta. In the present study, the effect of body temperature on delta CBF/delta PaCO2 was studied. delta CBF/delta PaCO2 was not significantly affected by body temperature. It was concluded that if delta CBF/delta PaCO2 remains constant with changes in body temperatures and CBF is controlled by CO2, CBF should increase with temperature due to the temperature-induced increase in PaCO2.

摘要

二氧化碳对脑血流量（CBF）的化学调节作用已在一种变温脊椎动物中得到证实（戴维斯，《美国生理学杂志》260: R382，1991）。脑血管对二氧化碳的敏感性（ΔCBF/ΔPaCO2），即脑血管对二氧化碳的血管反应性的一种度量，在常氧条件下，淡水龟（伪彩龟）的该值为0.7 ml·min-1·100 g-1·Torr-1，在缺氧条件下为3.4。在本研究中，研究了体温对ΔCBF/ΔPaCO2的影响。ΔCBF/ΔPaCO2不受体温的显著影响。得出的结论是，如果ΔCBF/ΔPaCO2随体温变化保持恒定，且脑血流量由二氧化碳控制，那么由于体温诱导的动脉血二氧化碳分压（PaCO2）升高，脑血流量应随温度升高。