Studies on the Natural History of the Norepinephrine Model of Acute Renal Failure in the Dog

Abstract
Studies on the natural history of the norepinephrine (NE) model of acute renal failure (ARF) in the dog. Group I (n = 6) was infused with NE into the renal artery (0.75 µg/kg/min × 80 min) and glomerular filtration rate (GFR) determined sequentially. 21 days post-NE infusion (I) the GFR of the I kidneys (20 ± (SE) 5 ml/min) remained less (p < 0.001) than the pre-I control value (44 ± 2.9). Group II (n = 7) was treated in an identical fashion except that a contralateral nephrectomy (CN) was done on day 7 and the animals were prepared for micropuncture on day 16. In the animals with residual nephron function at CN, the GFR increased (p < 0.02) from 26 ± 6.4 ml/min on day 7 to 38 ± 6.6 ml/min on day 14. Considerable interanimal heterogeneity of single nephron GFR (SNGFR) was demonstrated and morphologic studies revealed a very patchy lesion. Therefore, the model is reversible, heterogeneity of SNGFR is present, and the residual functioning nephrons have the capacity to undergo an increase in GFR after CN.