Studies on the fate of 14C-labeled oxolinic acid, (2)

Distribution patterns of 14C-labeled oxolinic acid, a new synthetic antimicrobial agent, were studied in mice, rats, hen quails and eels by means of whole body autoradiography. In mice 14C-oxolinic acid administered orally in a dose of 20 mg/kg was absorbed to a considerable extent from the intestinal tract, and was distributed in almost all tissues. At 30 to 60 minutes after the administration, the highest concentrations of radioactivity were observed in the liver, kidney myocardium, bone, and brown fat; while radioactivities were moderate in the blood, skeletal muscle, adrenal gland and pituitary gland, and lowest in the central nervous system and testis. The concentration in the fetus at 60 minutes after the administration was about equal to that of the placenta, and then it gradually decreased with a lapse of time. In the tissues of the fetus high concentrations of radioactivity were found especially in the bone. The radioactivity was almost completely eliminated from mice bodies within 48 hours after the administration. In rats the distribution pattern was very similar to that in mice. But, the uptake of radioactivity into brown fat was considerably less in rats than that in mice. In hen quails, the distribution patterns resembled those in mice and rats. It was of note that the compound was localized in the tissues containing melanin in the eye, skin and hair follicles; but it was only slightly incorporated into the maturing follicles of the ovary. In eels, the absorption and elimination of the compound seem to be very slow. (auth.)