Quantitative method for the study of the morphological changes induced by vasoactive agents in single aortic myocytes...

Morphological changes of aortic myocytes grown in primary cultures on collagen gels, were induced by two adrenergic agonists, in the absence or presence of specific antagonists. Their effects were quantified by means of the measurement of the surface areas of the images of the cells. The alpha-adrenoreceptor agonist phenylephrine induced a concentration-dependent decrease of the surface areas of the images of the cells, which was competitively antagonized by phentolamine, and was reduced in the presence of CdCl2 (an inhibitor of calcium entry). The beta-adrenoreceptor agonist isoproterenol induced an increase in the surface areas of the images of prostaglandin F2-alpha pretreated cells and this effect was antagonized by propranolol. It is concluded that the morphological changes of myocytes in primary culture, induced by phenylephrine or isoproterenol can be quantified by the measurement of the surface areas of their images. These changes were in good agreement with the response of isolated thoracic aorta rings or strips to the same agonists with regard to their sensitivity, specificity, and kinetic features. Thus the measurement of the changes of the surface area of the images of myocytes induced by vasoactive agents constitutes a noninvasive, nondestructive method for the quantification of their responses to these agents at the single cell level.