Glomerular Hypertrophy in Offspring of Subtotally Nephrectomized Ewes

Department of Physiology and Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.
The Anatomical Record Advances in Integrative Anatomy and Evolutionary Biology (Impact Factor: 1.54). 03/2008; 291(3):318-24. DOI: 10.1002/ar.20651
Source: PubMed


We have shown that fetuses whose mothers underwent subtotal nephrectomy (STNx) before pregnancy had high urine flow rates and sodium excretions, but lower hematocrits, plasma chloride, and plasma renin levels compared with controls. To see if these functional differences in utero persist after birth and are the result of altered renal development, we studied 8 lambs born to STNx mothers (STNxL) and 10 controls (ConL) in the second week of life. These lambs were of similar body weights, nose-rump lengths and abdominal girths. Their kidney weights were not different (ConL 36.1 +/- 1.9 vs. STNxL 39.8 +/- 3.3 g), nor were kidney dimensions or glomerular number (ConL 423,520 +/- 22,194 vs. STNxL 429,530 +/- 27,471 glomeruli). However, STNxL had 30% larger glomerular volumes (both mean and total, P < 0.01) and there was a positive relationship between total glomerular volume and urinary protein excretion (P < 0.05) in STNxL. Despite this change in glomerular morphology, glomerular filtration rate, tubular function, urine flow, and sodium excretion rates were not different between STNxL and ConL, nor were plasma electrolytes, osmolality, and plasma renin levels. Thus while many of the functional differences seen in late gestation were not present at 1-2 weeks after birth, the alteration in glomerular size and its relationship to protein excretion suggests that exposure to this altered intrauterine environment may predispose offspring of mothers with renal dysfunction to renal disease in adult life.

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Available from: John F Bertram, Oct 09, 2014
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    • "Together these findings suggest that there is a larger surface area for filtration in fetuses of STNx ewes, along with an enlarged proximal tubule. K f is a function of filtration surface area and the hydraulic conductivity of the filtration barrier, and although we cannot comment on differences in hydraulic conductivity we have previously reported that 1–2-week-old lambs born to STNx ewes had enlarged glomeruli (glomerular volume was increased by 30% while glomerular number was not altered) (Brandon et al. 2008). Since the fetuses in the current study were close to term, and it is recognized that nephron formation is complete by 130 days in the fetal sheep (Robillard et al. 1981), it is likely that the glomerular hypertrophy we observed in after birth in STNx offspring, was already present. "
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