Effect of kidney surface temperature on single nephron filtration rate.

Abstract

SummaryIn dog kidneys prepared for micropuncture experiments, the thesis that exteriorized organs with an intact circulation may demonstrate reduced function due to exposure to cool (21-23°) room temperatures, was tested by measuring superficial proximal and distal SNGFR on the surface of kidneys either protected against heat loss with a plastic wrap or unwrapped and exposed to room temperature. No significant differences in GFR or RBF could be detected between these conditions. However, temperature at the kidney surface was 37° in wrapped kidneys but fell (P < .002) to 35° in the unwrapped state. The lower surface temperature was associated with reduced values for proximal SNGFR, 72 ± 7 vs. 52 ± 4 nl/min (P < .02) and distal SNGFR, 46 ± 4 vs. 30 ± 7 nl/min (P < .02). The results indicate that the uninsulated kidney prepared for micropuncture may have decidedly lower values for superficial SNGFR measured by total collections of tubular fluid from either proximal or distal sites. These data also suggest th...