Abstract
Hypertension and renal dysfunction can be programmed in the rat by prenatal exposure to a low-protein (LP) diet. Expression of the renal thick ascending limb (TAL) sodium transporter NKCC2 is up-regulated, which has been predicted to result in greater sodium reabsorption. However, we have shown that LP rats excrete more not less sodium. The aim of this study was to determine whether the increased abundance of sodium:potassium:chloride (Na+:K+:2Cl-) co-transporter (NKCC2) leads to enhanced sodium uptake by the TAL. Pregnant Wistar rats were fed a control (18%) or LP (9%) diet. Amiloride (AM), bendroflumethiazide (BF), and furosemide (FUR) were administered acutely to male offspring at 4 weeks of age. Fractional excretion of sodium (FENa) was significantly greater in vehicle-infused LP rats (3.0 ± 0.3%) compared with controls (1.7 ± 0.5, P < 0.01). FENa by the LP proximal tubule did not differ from controls, whereas FENa by the distal tubule was significantly greater (P < 0.01). These differences were abolished by the administration of AM + BF (equivalent to the outflow from the TAL) and AM + BF + FUR (equivalent to the outflow from the proximal tubule), suggesting that the increase in NKCC2 expression was not functional. However, during acute salt loading, the LP rat pressure natriuresis curve was shifted rightward, implying that raised systemic blood pressure is required to match urinary sodium excretion with dietary intake. These data suggest that renal sodium handling is impaired in the LP rat but that this is not due to increased NKCC2 expression.
Similar content being viewed by others
References
Barker DJ, Osmond C, Kajantie E, Eriksson JG (2009) Growth and chronic disease: findings in the Helsinki Birth Cohort. Ann Hum Biol 36:445–458
Langley-Evans SC (2009) Nutritional programming of disease: unravelling the mechanism. J Anat 215:36–51
Seckl JR (2004) Prenatal glucocorticoids and long-term programming. Eur J Endocrinol 151(Suppl 3):U49–U62
Hughson MD, Douglas-Denton R, Bertram JF, Hoy WE (2006) Hypertension, glomerular number, and birth weight in African Americans and white subjects in the southeastern United States. Kidney Int 69:671–678
Wintour EM, Moritz KM, Johnson K, Ricardo S, Samuel CS, Dodic M (2003) Reduced nephron number in adult sheep, hypertensive as a result of prenatal glucocorticoid treatment. J Physiol 549:929–935
Sahajpal V, Ashton N (2003) Renal function and angiotensin AT1 receptor expression in young rats following intrauterine exposure to a maternal low-protein diet. Clin Sci (Lond) 104:607–614
Brenner BM, Garcia DL, Anderson S (1988) Glomeruli and blood pressure. Less of one, more the other? Am J Hypertens 1:335–347
Hoppe CC, Evans RG, Moritz KM, Cullen-McEwen LA, Fitzgerald SM, Dowling J, Bertram JF (2007) Combined prenatal and postnatal protein restriction influences adult kidney structure, function, and arterial pressure. Am J Physiol Regul Integr Comp Physiol 292:R462–R469
Denton KM, Kett MM, Dodic M (2006) Programming hypertension animal models: causes and mechanisms. In: Wintour EM, Owens JA (eds) Early Life Origins of Health and Disease. Eureka.com/Landes Bioscience, New York, pp 103–120
Dotsch J (2009) Renal and extrarenal mechanisms of perinatal programming after intrauterine growth restriction. Hypertens Res 32:238–241
Vehaskari VM, Woods LL (2005) Prenatal programming of hypertension: lessons from experimental models. J Am Soc Nephrol 16:2545–2556
Dagan A, Kwon HM, Dwarakanath V, Baum M (2008) Effect of renal denervation on prenatal programming of hypertension and renal tubular transporter abundance. Am J Physiol Renal Physiol 295:F29–F34
Dagan A, Gattineni J, Cook V, Baum M (2007) Prenatal programming of rat proximal tubule Na+/H+ exchanger by dexamethasone. Am J Physiol Regul Integr Comp Physiol 292:R1230–R1235
Dagan A, Habib S, Gattineni J, Dwarakanath V, Baum M (2009) Prenatal programming of rat thick ascending limb chloride transport by low-protein diet and dexamethasone. Am J Physiol Regul Integr Comp Physiol 297:R93–R99
Alwasel SH, Ashton N (2009) Prenatal programming of renal sodium handling in the rat. Clin Sci (Lond) 117:75–84
Manning J, Beutler K, Knepper MA, Vehaskari VM (2002) Upregulation of renal BSC1 and TSC in prenatally programmed hypertension. Am J Physiol 283:F202–F206
Bertram C, Trowern AR, Copin N, Jackson AA, Whorwood CB (2001) The maternal diet during pregnancy programs altered expression of the glucocorticoid receptor and type 2 11β-hydroxysteroid dehydrogenase: potential molecular mechanisms underlying the programming of hypertension in utero. Endocrinology 142:2841–2853
Shalmi M, Thomsen K (1989) Alterations of lithium clearance in rats by different modes of lithium administration. Ren Physiol Biochem 12:273–280
Ahmed MH, Ashton N, Balment RJ (2003) The effect of chloroquine on renal function and vasopressin secretion: a nitric oxide-dependent effect. J Pharmacol Exp Ther 304:156–161
Shirley DG, Walter SJ, Sampson B (1992) A micropuncture study of renal lithium reabsorption: effects of amiloride and furosemide. Am J Physiol 263:F1128–F1133
Jonassen TE, Gronbeck L, Shalmi M, Petersen JS, Andreasen F, Christensen S (1995) Supra-additive natriuretic synergism between bendroflumethiazide and furosemide in rats. J Pharmacol Exp Ther 275:558–565
Garcia-Estañ J, Roman RJ (1989) Role of renal interstitial hydrostatic pressure in the pressure diuresis response. Am J Physiol 256:F63–F70
Roman RJ, Cowley AW Jr (1985) Abnormal pressure-diuresis-natriuresis response in spontaneously hypertensive rats. Am J Physiol 248:F199–F205
Mesquita FF, Gontijo JA, Boer PA (2010) Expression of renin-angiotensin system signalling compounds in maternal protein-restricted rats: effect on renal sodium excretion and blood pressure. Nephrol Dial Transplant 25:380–388
Thomsen K, Jonassen TE, Christensen S, Shirley DG (2002) Amiloride inhibits proximal tubular reabsorption in conscious euvolemic rats. Eur J Pharmacol 437:85–90
Ortiz LA, Quan A, Zarzar F, Weinberg A, Baum M (2003) Prenatal dexamethasone programs hypertension and renal injury in the rat. Hypertension 41:328–334
Gamba G, Friedman PA (2009) Thick ascending limb: the Na+:K+:2Cl- co-transporter, NKCC2, and the calcium-sensing receptor, CaSR. Pflugers Arch 458:61–76
Cowley AW Jr, Roman RJ (1996) The role of the kidney in hypertension. JAMA 275:1581–1589
Sahajpal V, Ashton N (2005) Increased glomerular angiotensin II binding in rats exposed to a maternal low protein diet in utero. J Physiol 563:193–201
Stewart T, Ascani J, Craver RD, Vehaskari VM (2009) Role of postnatal dietary sodium in prenatally programmed hypertension. Pediatr Nephrol 24:1727–1733
Cowley AW Jr (2008) Renal medullary oxidative stress, pressure-natriuresis, and hypertension. Hypertension 52:777–786
Sathishkumar K, Elkins R, Yallampalli U, Yallampalli C (2009) Protein restriction during pregnancy induces hypertension and impairs endothelium-dependent vascular function in adult female offspring. J Vasc Res 46:229–239
Torrens C, Brawley L, Anthony FW, Dance CS, Dunn R, Jackson AA, Poston L, Hanson MA (2006) Folate supplementation during pregnancy improves offspring cardiovascular dysfunction induced by protein restriction. Hypertension 47:982–987
Brawley L, Torrens C, Anthony FW, Itoh S, Wheeler T, Jackson AA, Clough GF, Poston L, Hanson MA (2004) Glycine rectifies vascular dysfunction induced by dietary protein imbalance during pregnancy. J Physiol 554:497–504
Stewart T, Jung FF, Manning J, Vehaskari VM (2005) Kidney immune cell infiltration and oxidative stress contribute to prenatally programmed hypertension. Kidney Int 68:2180–2188
Sherman RC, Jackson AA, Langley-Evans SC (1999) Long-term modification of the excretion of prostaglandin E2 by fetal exposure to a maternal low protein diet in the rat. Ann Nutr Metab 43:98–106
Cambonie G, Comte B, Yzydorczyk C, Ntimbane T, Germain N, Le NL, Pladys P, Gauthier C, Lahaie I, Abran D, Lavoie JC, Nuyt AM (2007) Antenatal antioxidant prevents adult hypertension, vascular dysfunction, and microvascular rarefaction associated with in utero exposure to a low-protein diet. Am J Physiol Regul Integr Comp Physiol 292:R1236–R1245
Conflict of interest
None.
Funding
This work was supported by funds from the Fetal Programming of Diseases Research Chair, King Saud University, Saudi Arabia (SHA).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Alwasel, S.H., Ashton, N. Segmental sodium reabsorption by the renal tubule in prenatally programmed hypertension in the rat. Pediatr Nephrol 27, 285–293 (2012). https://doi.org/10.1007/s00467-011-1976-9
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00467-011-1976-9