Ultrastructural morphological evaluation of renal nerve alterations in experimentally induced diabetic rats

Abstract

Changes in multiple sensory inputs and central nervous system activity influence efferent renal sympathetic nerve activity, thereby altering kidney function. The renal nerves contain efferent sympathetic nerve fibers important in regulating renal function and afferent fibers that transmit sensory information from the kidneys to the central nervous system. The innervation within mammalian kidneys (intrinsic innervation) has been extensively described in the literature, particularly for rats. In contrast, few studies have provided a detailed description of the morphology of the extrinsic renal nerves leading to the kidney. Recently, we have provided a detailed morphologic and morphometric description of the extrinsic renal nerves in rats, by a transmission electron microscopy study. The extrinsic renal nerves are of interest because they are the site for recording of sympathetic nerve activity and electrical stimulation in functional studies. Streptozotocin (STZ) induced diabetes is known to cause a reduction of conduction velocity and axon caliber in rat nerves, being one of the most extensively studied experimental model of diabetes. The aims of the present study are to describe morphometric characteristics of the extrinsic renal nerves in acute and chronically STZ-induced diabetic rats and to determine if these characteristics are modified by conventional insulin treatment. (AU)