Maternal dexamethasone exposure does not affect glucose tolerance but alters renal haemodynamics in F1 rats in a sex-dependent manner

Abstract

Introduction

Prenatal programming with dexamethasone increases the risk of the development of hyperglycaemia and insulin resistance, leading to diabetes in adulthood. Dexamethasone also causes a decline in renal glomerular filtration in the adult offspring. Sodium-glucose cotransporter-2 (SGLT2) plays a significant role in regulating blood glucose and renal haemodynamics in diabetic patients. However, the role of SGLT2 in dexamethasone-induced programming and the putative sex-dependent effects on the changes named earlier is unknown. Therefore, this study aimed to investigate the impact of maternal dexamethasone treatment on glucose tolerance, insulin sensitivity, renal perfusion and renal function in adult male and female offspring and the possible contribution of SGLT2 to these changes.

Methods and Results

Pregnant Sprague Dawley rats (F₀) were treated with either vehicle or dexamethasone (0.2 mg/kg ip) from gestation Day 15 to 20. F₁ males and F₁ females were randomly selected from each mother at 4 months of age. There was no change in serum Na⁺, Na⁺ excretion rate, glucose tolerance or insulin sensitivity in F₁ male or female rats. However, dexamethasone caused significant glomerular hypertrophy and decreases in C_Sinistrin and C_PAH indicating decreased glomerular filtration rate and renal plasma flow, respectively, in dexamethasone-treated F1 male but not female rats. Dexamethasone did not affect SGLT2 mRNA or protein expression in F₁ males or females.

Conclusion

We conclude that dexamethasone-mediated prenatal programming of glomerular volume, renal function and haemodynamics is sex-dependent, occurring only in adult male offspring.