Studies of a new fatty acid analog (DMIVN) in hypertensive rats and the effect of verapamil using ARG microimaging.

Studies of myocardial utilization of fatty acids and analogs has focused on coronary heart disease. This study addresses the topic of radioiodinated fatty acid utilization in hypertensive-cardiomyopathy. The new fatty acid analog 19-iodo-3,3-dimethyl-18 nonadecenoic acid (DMIVN) was studied by autoradiographic microimaging (ARG) in salt-sensitive (S) hypertensive (salt-fed) and in salt-sensitive (S) normotensive (low-salt diet), Dahl-strain rats. A salt fed, S-strain group was treated with verapamil and the results were compared to those in a hypertensive, non-treated group. The distribution of DMIVN in the hearts of normotensive rats was uniform. In the myocardium of hypertensive rats nonuniform DMIVN concentration was seen in the subendocardial and mid-layers of the left ventricle (LV). Verapamil given to salt-fed rats prevented hypertension and uniform DMIVN uptake similar to normotensive controls was seen. The data suggest that DMIVN may be suitable for the detection of hypertension induced myocardial changes and for assessing therapy. The distribution and clearance characteristics of DMIVN indicate that DMIVN may be a useful agent for SPECT imaging in man.