518 5. QUINONES 



mice die (Vollmer and Buchholz, 1930). The administration of lactate for 

 several days also increases the susceptibility to the hydroqiiinone. Vollmer 

 (1932 a) pointed out that the toxicity depends on the weight of the animal; 

 at a dose of 200 mg/kg subcutaneously, p-benzohydroquinone kills over 

 90% of mice under 14 g, but less than 45% of mice over 16 g. This was 

 related to the higher rate of metabolism in the smaller animals. Mice made 

 tolerant to alcohol are more sensitive to ^>benzohydroquinone, and again 

 this was interi)reted in terms of metabolic levels, the alcohol-resistant 

 animals being thought to have a faster metabolism (Vollmer, 1932 b). Ob- 

 viously, such results are open to other interpretations and it is well known, 

 for example, that age and weight influence the susceptibilities to many 

 drugs where metabolic rate is probably not the factor involved. It is difficult 

 to see how lactate could increase the oxidizing ability in the blood or tis- 

 sues, and the hyperthyroid mice might suffer from metabolic disturbance 

 more readily than normal mice because of the greater energy requirements 

 of their actively functioning tissues. Marquardt et al. (1947) repeated the 

 work on thyroxine and examined several phenols and polyphenols (see 

 accompanying tabulation). A ratio less than 1 indicates that hyperthyroid- 



ism reduces the susceptibility. Vollmer's results with p-benzohydroquinone 

 were not confirmed, and indeed there was a small decrease in susceptibility. 

 The effect of thyroid seems to depend on the nature of the substance tested 

 and probably on the mechanisms involved in the toxicity. 



Poisoning in Man 



Five cases of severe poisoning by ^-bcnzohydroquinone have been found 

 in the literature. These have resulted mainly from the ingestion of photo- 



