Electroneuromyographic Investigation of the Sciatic Nerve in Spontaneously Hypertensive Rats: Comparison Between Age and Gender

Abstract

Previous results from our laboratory have shown morphological alterations on the sural nerves of female spontaneously hypertensive rats (SHR), mainly on the small myelinated fibers but there are no investigations on the functional significance of these alterations. Also, there are no reports on nerve functional differences between genders and age, particularly on the SHR. The present study investigated the alterations on the electrophysiological parameters of the sciatic nerves of male and female SHR with 5 and 8 weeks of age, compared to their normotensive controls WKY. After direct measurements of arterial pressure (cuff tail method), rats were anesthetized and electroneuromyographic studies were performed with the aid of a Keypoint® 4, Dantec‐Medtronic® equipment. Body weight and sensory and motor conduction velocities were significantly higher in older animals, for both genders and strains. Nevertheless, blood pressure values were similar between genders and strains, indicating that the SHR animals have not became hypertensive in the ages studied. The increase in the conduction velocity values reflects the nerve fibers growth that follows the animals aging.