The influence of bactericidal agents and of the absence of l-ascorbic acid on the accumulation of hydroxyphenyl compounds in the large intestine of guinea pigs after the consumption of high doses of l-tyrosine

Abstract

Three hours after the admn. of 0.5 g. of L-tyrosine more hydroxyphenyl compounds were found in the large intestine, particularly in the cecum, of guinea pigs which were depleted of L-ascorbic acid and in that of guinea pigs receiving sulfaguanidine, succinylsulfathiazole or phthalylsulfa-thiazole with cabbage ad lib. than in guinea pigs receiving vit C in the form of cabbage or L-ascorbic acid in soln. without the bactericidal agents. Expts. are descr. in which the influence of the mode of admn. and of the quantity of the added L-ascorbic acid was investigated, and it was concluded that L-ascorbic acid as present in cabbage is more effective than as the synthetic compound in soln. A great part of the hydroxyphenyl compounds present in the large intestine of the depleted guinea pigs 3 hrs. after the admn. of the L-tyrosine was found in the urine of the animals 21 hrs. later. Only a small portion of these accumulated compounds was present in the urine of the guinea pigs receiving cabbage ad lib. and sulfaguanidine. The concns. of hydroxyphenyl compounds in the walls of the intestine, the blood, the liver, the kidney and the muscle were much higher in the depleted animals and in the animals receiving cabbage ad lib. without sulfaguanidine than in the corresponding tissues of animals receiving the bactericidal agent. Excluding a very rapid passage into the blood stream, it may be assumed that the lower content of hydroxyphenyl compounds in the large intestine of the animals receiving cabbage ad lib. or synthetic L-ascorbic acid in soln. without sulfaguanidine is due to the influence of the intestinal bacterial flora which is modified by either the absence of L-ascorbic acid from or the presence of bactericidal agents in the diet of the guinea pigs. In the 1st case, owing to the free passage into the circulation, the concn. in the blood reaches levels which are too high for these hydroxyphenyl compounds to be metabolized normally. In the 2d case the impaired passage into the blood stream brought about by the consumption of the bactericidal agents prevented the production of such a critical concn. of hydroxyphenyl compounds in the circulation, and the greater part of these compounds was destroyed slowly during passage along the large intestine.