TY - JOUR
T1 - Attenuated response of renal mechanoreceptors to volume expansion in chronically hypoxic rats
AU - Chien, Chiang Ting
AU - Fu, Tsu Ching
AU - Wu, Ming Shiou
AU - Chen, Chau Fong
PY - 1997
Y1 - 1997
N2 - Multifiber renal afferent nerve activity responds to volume expansion in sea level rats but not in chronically hypoxic (high altitude) rats. We performed single-unit recordings of renal afferent nerve activity to characterize renal sensory receptors and their responses to volume expansion in these animals. Hypoxia was induced by placing Wistar rats in an altitude chamber (380 Torr, 5,500 m) for 4 wk. Spontaneously firing renal R2 chemoreceptor and arterial, ureteropelvic, and venous mechanoreceptors were identified. The basal activity of each receptor was similar among these rats. In response to specific stimulus, the increasing impulse of R2 chemoreceptor was similar between two groups of rats, but the increasing activity of each mechanoreceptor was less in hypoxic rats. When challenged with saline load, R2 chemoreceptor activity decreased, but all mechanoreceptors activated in all rats. Despite similar increases of arterial, renal ureteropelvic, and venous pressure during saline load, the increasing activity of each mechanoreceptor was significantly less in hypoxic rats. These results indicated chronic hypoxia attenuates the sensitivity of renal mechanoreceptors in response to the stimulation of saline load.
AB - Multifiber renal afferent nerve activity responds to volume expansion in sea level rats but not in chronically hypoxic (high altitude) rats. We performed single-unit recordings of renal afferent nerve activity to characterize renal sensory receptors and their responses to volume expansion in these animals. Hypoxia was induced by placing Wistar rats in an altitude chamber (380 Torr, 5,500 m) for 4 wk. Spontaneously firing renal R2 chemoreceptor and arterial, ureteropelvic, and venous mechanoreceptors were identified. The basal activity of each receptor was similar among these rats. In response to specific stimulus, the increasing impulse of R2 chemoreceptor was similar between two groups of rats, but the increasing activity of each mechanoreceptor was less in hypoxic rats. When challenged with saline load, R2 chemoreceptor activity decreased, but all mechanoreceptors activated in all rats. Despite similar increases of arterial, renal ureteropelvic, and venous pressure during saline load, the increasing activity of each mechanoreceptor was significantly less in hypoxic rats. These results indicated chronic hypoxia attenuates the sensitivity of renal mechanoreceptors in response to the stimulation of saline load.
KW - Chronic hypoxia
KW - Renal chemoreceptor
KW - Renal mechanoreceptor
KW - Renal nerve
KW - Saline load
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U2 - 10.1152/ajprenal.1997.273.5.f712
DO - 10.1152/ajprenal.1997.273.5.f712
M3 - Article
C2 - 9374834
AN - SCOPUS:0030724148
SN - 1931-857X
VL - 273
SP - F712-F717
JO - American Journal of Physiology - Renal Physiology
JF - American Journal of Physiology - Renal Physiology
IS - 5 42-5
ER -