Neural control of renal hemodynamics and function during development.

This review summarizes our current understanding of the role of the renal sympathetic nervous system during development. Recent evidence suggests that renal innervation appears early during fetal life and may play an important role in promoting cellular development. It has also been observed that renal nerve stimulation decreases renal blood flow and increases renal vascular resistance in fetal sheep, but to a lesser extent than in newborn and adult sheep. Moreover, it has been shown that, contrary to previous findings in adult animals, renal nerve stimulation during alpha-adrenoceptor blockade induces renal vasodilation in fetal and newborn sheep, but not in adult sheep. Recent studies have also demonstrated that renal nerves modulate the natriuretic response to a saline load in newborn lambs and influence sodium reabsorption in near-term fetal sheep. The role of renal nerves and neuronally released norepinephrine on renin secretion in the developing kidney is discussed. Finally, it is suggested that efferent renal sympathetic nerve activity might influence fetal renal hemodynamics during stressful conditions.