Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA248

Poster Communications

Time-Dependent Effects of High Salt Diet on Renal Functions in adult Female Wistar Rats

N. Lasheen1,2, A. Mohamed1

1. Physiology, Faculty of Medicine Ain Shams University, Cairo, Egypt. 2. Physiology, New Giza University, School of Medicine, Giza, Egypt.

Background: High salt diet induces sodium glomerulopathy, with the consequence of impaired renal functions. These renal sodium-dependent effects are thought to the hypertensive effects of high sodium intake, or to increased TGF- β1 levels. However, the duration of high sodium loading may play a role in the development and the severity of such renal effects. Moreover, the high sodium loading could alter the endocrinal renal functions. Aim: to investigate and compare the effects of high salt diet, for two different durations, on both endocrinal and excretory renal functions in rats. Materials and Methods: 40 adult female Wistar rats were divided into control group (C, n=20); fed diet containing 0.3% NaCl, 2 week and 12 week-high salt fed groups; fed diet with 8% NaCl for 2 (HS-2W, n=10) and 12 (HS-12W, n=10) weeks respectively. At the end of experimental period, blood pressure was measured. Rats were anaesthetized by i.p. pentobarbitone (40μg/kg B.W.). The separated plasma was used for determination of urea, creatinine, sodium, potassium, aldosterone, plasma renin activity, erythropoietin and TGF-β1. Left kidney of all rats was assayed for renal tissue nitric oxide (NO) and α1 hydroxylase activity.Statiscal analysis by One way ANOVA was performed. Results: High salt diet for 2 weeks caused only a significant rise in plasma levels of urea and TGF-β1 in the HS-2W compared to the C group. HS-12W group exhibited significant rise in plasma levels of urea, creatinine, sodium, potassium, aldosterone, and plasma renin activity, renal tissue NO level, systolic and diastolic pressure values compared to either the C group or the HS-2W group. Plasma erythropoietin level and renal tissue α1 hydroxylase were significantly lowered in the HS-12W group compared to either the C or the HS-2W groups. Moreover, plasma TGF-β1 was significantly elevated in HS-12W group compared to the C group only. Conclusion: High salt diet for longer duration has more detrimental effects on exocrine and endocrinal kidney functions through elevating TGF-β1.

Where applicable, experiments conform with Society ethical requirements