Cochlea and Heart as End-Organs in Small Vessel Disease

Many studies have been done recently to determine the role of various stresses on the heart and peripheral vasculature. Although damage to coronary arteries and renal vessels has been well described, the ear as an end-organ in small vessel disease has been largely neglected. In a previous study, we examined the effects of noise, hypertension, and an atherogenic diet on the microvasculature of the cochleas in rats. The present study examines the effects of these stresses on the hearts of the same rats. The technique used to examine microvascular blood flow was the injection of unlabeled microspheres prior to killing. We found that the blood flow in the cochleas was reduced significantly in hypertensive animals exposed to noise or an atherogenic diet compared to that of normotensive or hypertensive control animals. The hearts of such animals, however, showed decreased myocardial blood flow only when compared to those of normotensive control animals, not when compared to those of hypertensive control animals.