COMPENSATORY ADAPTATION TO REDUCED RENAL MASS IN THE NEWBORN GUINEA PIG (GP)

Abstract

In order to identify the physiologic adaptation to compensatory renal hypertrophy in the newborn, right uninephrectomy (NX)or sham (S) operation was performed in GP within the first 36 hrs. of life. At 3 wks. of age, they were studied using clearance and micropuncture techniques. Body weight (BW), left kidney weight (LKW), and arterial blood pressure (ABP) were measured. Left kidney glomerular filtration rate (LKGFR) and single nephron GFR (SNGFR) were measured by clearance of 14C inulin. Proximal tubula pressure (PT) and stop flow pressure (SFP) were measured using a servonulling device. Glomerular capillary pressure (PGC) was estimated from the sum of SFP and colloid oncotic pressure. Results (mean±SE, n = Number of animals, NS = not significant):

Conclusions: 1) Growth in the neonatal GP is unaffected by NX, 2) 3wks. following NX, there is a 41% increase in mass and a 68% increase in GFR of the renoprival kidney, 3) There is a parallel increase in SNGFR, indicating a significant contribution of immature superficial cortical nephrons to the adaptive process, 4) The increased SNGFR is not due to changes in ABP, P_GC, or P_T.

Log in or create a free account to read this content

Gain free access to this article, as well as selected content from this journal and more on nature.com

Access through your institution

or

Sign in or create an account

Continue with Google

Continue with ORCiD