Compensatory renal hypertrophy following nephrectomy: When and how?

Abstract

Following surgical removal of one kidney, the other enlarges and increases its function. The mechanism for the sensing of this change and the growth is incompletely understood but begins within days and compensatory renal hypertrophy (CRH) is the dominant contributor to the growth. In many individuals undergoing nephrectomy for cancer or kidney donation this produces a substantial and helpful increase in renal function. Two main mechanisms have been proposed, one in which increased activity by the remaining kidney leads to hypertrophy, the second in which there is release of a kidney specific factor in response to a unilateral nephrectomy that initiates CRH. Whilst multiple growth factors and pathways such as the mTORC pathway have been implicated in experimental studies, their roles and the precise mechanism of CRH are not defined. Unrestrained hypoxia inducible factor activation in renal cancer promotes growth and may play an important role in driving CRH.

Physiology and Pathophysiology of Compensatory Adaptations of a Solitary Functioning Kidney

“…Other factors such as the nitric oxide system, the renal sympathetic nerves and the renin angiotensin system (RAS) have been implicated in the compensatory adaptations to reduction in kidney mass ( Rojas-Canales et al, 2019 ). Nitric oxide (NO), released by the endothelium, is an important vasodilator of the vasculature.…”

Renal developmental genes are differentially regulated after unilateral ureteral obstruction in neonatal and adult mice

“…Compensatory growth is different from normal growth. At a cellular level, it is predominantly characterized by cellular hypertrophy (increased cell size and mass), and less by hyperplasia (increased cell number) 59 . Increased cell size is due to stimulated RNA and protein synthesis, which is regulated by mTORC1 (mammalian target of rapamycin complex 1) signaling.…”

Compensation Capacity of The Living-Related Donor’s Remnant Kidney and Recipient’s Transplanted Kidney

“…The kidney presents a functional reserve capacity after unilateral nephrectomy [1,2]. Many studies reported that the donor's global renal function decreased immediately after kidney donation [5].…”

“…Two main mechanisms have been proposed. One ascribes it to the increased activity of the remnant kidney that leads to hypertrophy, and the other attributes it to the release of kidney speci c factors such as insulin-like growth factor 1, epidermal growth factor and hepatocyte growth factor and pathways such as mammalian target of rapamycin in response to unilateral nephrectomy [1,8].…”

“…Compensatory growth of the contralateral kidney to promote signi cant restoration of the lost renal function is a common phenomenon after unilateral radical nephrectomy [1,2]. The glomerular ltration rate (GFR) is a generally accepted parameter to evaluate the renal function.…”