Renal sympathetic nerve activity and the weight of the remaining kidney in unilateral nephrectomized rats.
To examine compensatory response of the kidney to reduction in renal mass, acute and chronic effects of unilateral nephrectomy on renal sympathetic nerve activity (RNA) and weight of the remaining kidney were analyzed in rats. Under acute nephrectomy, RNA decreased significantly due to ligation of the renal vessels, ureter and nerves. With acute unilateral renal denervation, basal mean RNA (MRNA) did not change but the reflex inhibition of RNA due to ligation disappeared. Chronic effects of nephrectomy were analyzed at 3, 7, 14 and 28 days after surgery. At 3, 7, 14 and 28 days after nephrectomy, MRNA were about two times larger than the values obtained in sham operation group (p < 0.01). Changes in arterial pressure and heart rate were not significant after unilateral nephrectomy. When the maximal MRNA due to dimethylphenylpiperazinium iodide (DMPP) administration was set as 100%, relative basal MRNA at 3, 7, 14 and 28 days were estimated in sham and nephrectomy groups. Also, relative basal MRNA increased about two times in nephrectomy group. After unilateral nephrectomy, the remaining kidney weight per unit body weight increased significantly by 18-35%. These findings indicate that the RNA in the remaining kidney was reflexly inhibited by the activation of afferent input due to ligation of renal vessels, ureter and nerves under acute nephrectomy. Under chronic unilateral nephrectomy, basal MRNA and the weight of the remaining kidney were increased significantly. The RNA per unit of kidney weight in unilateral nephrectomized rats was increased at 3 and 7 days and then it was relatively constant at 14 and 28 days.
Furukawa
K
K
Department of Physiology, School of Medicine, Hiroshima University, Japan.
Ninomiya
I
I
Shimizu
J
J
Wada
T
T
Matsuura
Y
Y
D000200:Action Potentials / Q000187:drug effects; D000222:Adaptation, Physiological; D000818:Animals; D004246:Dimethylphenylpiperazinium Iodide / Q000494:pharmacology; D005731:Ganglionic Stimulants / Q000494:pharmacology; D006439:Hemodynamics; D007668:Kidney / Q000294:innervation* / Q000473:pathology; D008297:Male; D009392:Nephrectomy; D009929:Organ Size; D011184:Postoperative Period; D051381:Rats; D017208:Rats, Wistar; D013564:Sympathetic Nervous System / Q000502:physiology*; D013997:Time Factors
D005731:Ganglionic Stimulants; D004246:Dimethylphenylpiperazinium Iodide