SPONTANEOUSLY HYPERTENSIVE RATS AND PERIPHERAL NEUROPATHIES

Abstract

Type of the study: The present study is a literature review about the spontaneous hypertension animal model, and the consequences of the hypertension to the peripheral nervous system, somatic and autonomic. Importance of the topic: Hypertension is the main risk factor to stroke and vascular dementia, due to important cerebrovascular changes that may lead to cerebral microaneurysms, infarction and acute ischemia. The main central nervous system changes due to hypertension are the reduction of the cerebral volume, increase of the ventricles volume and loss of neurons. Moreover, hypertension causes renal alterations and other pathologies that might sustain the high blood pressure, the tachycardia and the elevation of the peripheral vascular resistance. The spontaneously hypertensive rat (SHR) is recognized as an excellent model of the human essential hypertension. Nevertheless, despite that this animal model has been widely explored in terms ofphysiological studies, morphological studies, when available, are limited to the vessels. Even when periphera  nerves are being explored, the epineural, perineural and endoneural vessels are the subject of the studies. Information on the alterations of the myelinated and unmyelinated fibers in this model of hypertension is scanty. Comments: Recently, we studied the morphology and morphometry of the aortic depressor nerve (ADN) in SHR and our results have demonstrated a reduction of the myelinated fibers size and a reduction of the number and size of the unmyelinated fibers, compared to the normotensive controls Wistar-Kyoto. Another recent study from our laboratory showed that, despite the significantly higher blood pressure and heart rate on male SHR, compared to female SHR, there are no morphological differences on the vagus nerves between males and females. Also, we have described the morphological and morphometric characteristics of the sural nerve in SHR, thus providing morphological background for further functional studies.