Argon laser micro-irradiation of mitochondria in rat myocardial cells in tissue culture : III. Irradiation of multicellular groups

Abstract

Single mitochondria of contracting myocardial cells were irradiated with an argon laser microbeam and the contractility changes of the cells were noted. Four series of irradiation experiments were conducted: (i) one cell of a two-cell group was killed, (ii) one cell of a multicell group was killed, (iii) one cell of a two-cell group was damaged, (iv) one cell of a multicell group was damaged. In series (i) and (ii) a majority of cells first fibrillated and then either returned to rhythmic contraction rate, or stopped contracting. In series (iii) and (iv) the individual contractility pattern following irradiation was quite variable, but by 30 min post irradiation a majority of the cells had returned to a rhythmic contraction rate. These studies demonstrate the feasibility of using the laser microbeam to investigate cell-cell interactions, and factors involved in regulating myocardial cell contractility.