594 



12. RATES OF INHIBITION 



ing on the nature or kinetics of the inhibition by Hg++ but only show that 

 Hg'''+ kills the individual cells after varying periods of time. 



Variations between cells in tissue preparations can likewise modify the 

 rate of resi^onse to an inhibitor. Tissues are generally studied either as 

 slices or strips, or occasionally isolated and intact, but in all cases there 

 is significant inhomogeneity. In the first place, aside from the cells that are 



5 



t(MIN)— 



10 



15 



20 



25 



30 



35 



40 



Fig. 12-35. Plots of the logarithm of the .survivors against time for 

 the distribution curves in Fig. 12-33. 



primarily being studied, there are connective tissue cells, blood vessel cells, 

 and often many other types. In the second place, there is very likely to 

 be variation between the primary tissue cells; that is, in isolated uterine 

 or atrial strips, for example, the smooth muscle or myocardial cells are 

 not all alike. In addition to histological demonstrations of differences there 

 is some evidence from cellular membrane potentials that the population 



