Evaluation of contribution of cardiac sympathetic innervation to the development of essential hypertension

Essential hypertension or primary hypertension is defined as manifestation of high blood pressure without secondary reasons, which might be partially related to cardiac sympathetic hyperinnervation. Here, I present evidence that early chemical sympathectomy can reverse the development of essential hypertension in adult spontaneously hypertensive rats (SHR). Morphologically, in immunohistochemically stained hearts I observed and quantified changes in cardiac sympathetic fiber density of the left ventricle, and changes in cellular density in developing superior cervical ganglion (SCG). Physiologically, I measured the blood pressure using a non-invasive tail-cuff method and assayed the heart/ body weight ratio. I found that neonatal sympathectomy induced by 6-hydroxydopamine (6-OHDA) diminished cardiac sympathetic innervation and reduced blood pressure of 12-week-old SHR. This indicates existing bonds between cardiac sympathetic hyperinnervation and promoted development of hypertension. Taken together, this study provides evidence that early neonatal intervention directed towards modulation of sympathetic cardiac innervation can influence a course of essential hypertension development.