IN-VITRO QUANTIFICATION BY IMAGE-ANALYSIS OF INOTROPIC AND CHRONOTROPIC EFFECTS OF DRUGS ON CULTURES OF CARDIAC MYOCYTES

Quantitative image analysis is used to measure the inotropic and chron otropic effects of drugs on cultured heart cells maintained at 37 degr ees C on the stage of an inverted light microscope, and sequentially s uperfused with control and treatment media. The beating of the cardiac myocytes is evaluated by simultaneously selecting up to eight areas, including cell edges, from digitized video image. The sizes and positi ons of these areas are controlled by the operator. To analyze the moti on of cell edges in each area, the computer measures the shift of the mass center of pixels' grey levels. Finally, a few parameters are calc ulated for the eight areas and displayed graphically. In order to asse ss treatment effects, appropriate statistical tests are performed on t he data. Image analysis is an efficient screening test for evaluating the pharmacologic or toxic effects of a substance on isolated or cultu red cardiac myocytes from various species.