118 



molecules.-^ In 2 X ^^'^ ^^ ^^ abolishes the phosphorescent light 

 emission of riboflavine. In 2 X 10~* M it abolishes the phosphores- 

 cent light emission of acridine and that of rhodamin B, also if the 

 latter is increased by the addition of substances such as Ritaline or 

 thiamine. So it is capable of suppressing phosphorescence of other 

 substances in the whole range of concentrations in which it exerts 

 pharmacological activit)'. In a higher concentration, as 0.0014, it 

 is capable of quenching the phosphorescence of a new group of 

 substances, to which quinidine and atebrin belong, and it is pos- 

 sible that it kills the animal in these concentrations because it 

 quenches the excitation of molecules involved in processes indis- 

 pensable for life. Many biological catalysts are related in their 

 structure to quinidine and atebrin. 



Another remarkable property of chlorpromazine is that it is 

 capable of influencing the probabilities of the triplet-singlet tran- 

 sitions of other molecules in presence of low concentrations of 

 alcohol which cause a mixed fluorescence and phosphorescence. 

 In acridine (saturated watery solution plus 0.125% methanol) it 

 favored the blue singlet. Its action was strong at 0.00017 M and 

 still noticeable at 5 X '^^'^ ^- ^^ fluoresceine, rhodamin, and 

 riboflavine it favored the triplet. 



All this shows the high and colorful reactivity of chlorproma- 

 zine in relation to £* /« vitro in concentrations in which it exerts 

 its pharmacological action /« vivo. Taking into account that its 

 molecule is a chemically inert one, this experience strongly sup- 

 ports the assumption that it actually exerts its influence on biologi- 

 cal functions by interfering with £*. If it influences schizophrenic 

 behavior in concentrations smaller than those that affect basic 

 metabolism this may be due either to its accumulation in certain 

 nervous centers, or to the specific sensitivity of those centers to 

 alterations of £*. 



^ We can expect, accordingly, oxidative phosphorylation to be uncoupled 

 by chlorpromazine. This to be the case has been shown lately by Berger. 

 Strccker, and Waelsh. 



