1966 年 86 巻 10 号 p. 963-967
Changes of terephthalic acid concentration in blood plasma were studied in the rabbit, and the half-life of terephthalic acid in plasma was determined in the rabbit and the rat. Terephthalic acid, when intraperitoneally injected, was rapidly absorbed in plasma and then excreted from plasma into the urine through the kidney. Terephthalic acid concentration in plasma reached a maximum level within 1 hour after the injection and decreased gradually, and any detectable amount was not found after 24 hours. Half-life of terephthalic acid in plasma is about 1.8 hours. (Fig. 1). Terephthalic acid suspension was orally administered in doses of 200 and 100 mg./kg. each. Terephthalic acid concentration in plasma reached a maximum level within 8 to 10 hours, and decreased slowly. In this case terephthalic acid concentration in plasma was very low, which was only 11.7 μg./ml. at the 8th hour after the administration of 200 mg./kg. Half-life of terephthalic acid in plasma after its oral administration is 27 hours. (Fig. 1). These results indicate that tereththalic acid concentration in plasma after its oral administration is more influenced by its absorption through the digestive tract than by its excretion thruogh the kidney. Urine excretion ratios in the rabbit were 67% by oral administration and 93% by intraperitoneal injection. In the rat, half-life of terephthalic acid in plasma is about 1.0 hour in the case of intraperitoneal injeation and about 3.4 hours. after oral administration. Both the rates of urinary excretion and absorption through the gastrointestinal tract of terephthalic acid in the rat are faster than those in the rabbit.