The distribution of orally and intravenously administered 14C-oxazolam was studied in mice by means of whole-body autoradiography and in rats by scintillation counting of the organs and tissues. The radioactivity was found to be widely distributed in various tissues including the brain at 30 min after oral administration, reached the maximum levels within 1 hr and thereafter declined rather rapidly. The distribution patterns were similar for mice and rats, except that the brain uptake of the drug was appreciably higher in mice than in rats. A high affinity of oxazolam to the brain tissue was demonstrated by an extremely high and rapid uptake of radioactivity by the brain after intravenous injection in mice. The brain level reached its maximum at about 1 min after the injection and thereafter fell off rapidly, some retention of radioactivity being observed in the white matter of the brain-stem and in the trigeminal nerve. Autoradiographic studies in pregnant mice demonstrated that there is a slow and only a slight penetration of radioactivity through the placenta. A comparison of the excretion patterns of oxazolam after oral administration in mice, rats, dogs and man revealed that in mice and rats the excretion in the feces, mostly derived from the biliary excretion, was more important than that in the urine, while in dogs a larger part was excreted in the urine and in man the most part (ca. 80% of the dose) in the urine.
This paper is concerned with the emulsification of residual fuel to improve the combustion of marine diesel engines.The experiment was conducted to investigate the effective water particles size and the stability of emulsified fuel, and the effects of water particles size and water content ratio which were dispersed in fuel on engine performances and burning characteristics were investigated by means of a marine diesel engine.It has been found that the minuteness and homogeneity of water particles dispersed in fuel are the most important factors for applying emulsified fuel to marine diessel engines.
1. O-acetoglycolyl-S-furoyl thiamine (AFT)-35S and thiamine (B1)-35S showed obvious differerences in radioactivity in the whole body autoradiogram.2. Administration of AFT-35S exhibited the higher radioactivity in the muscles (heart, skeletal, diaphram, masseter), stomach, brain, brown fat tissue and blood comparing with the case of B1-35S. In these organs, the radioactivity derived from AFT-35S was found at higher concentration and was kept for a longer period as compared with B1-35S.3. AFT converted into thiamine and its phosphoric acid esters within an hour after the administration, and the most abundant derivatives of thiamine was thiamine diphosphate.4. As compared with B1-35S, AFT-35S showed a considerably higher concentration of thiamine diphosphate in various organs.
The distribution of 14C-anisotropine methbromide, a quaternary ammonium derivative of atropine, was studied in mice by whole-body autoradiographic technique. After i. p. and s. c. injections, the radioactivity was found to be mainly concentrated in the excretory organs : the liver, kidney, gall and urinary bladders, gastrointestinal tract and salivary gland, indicating a rapid excertion of the drug via both the urinary and biliary routes. In addition, the radioactivity was found to be accumulated specifically in the pancreas, gastric mucosa, walls of the spermatic and oviducts and uterus. Almost no accumulation was observed in the central nervous system, the muscular tissues and the endocrine organs. Autoradiography in mice of which the common bile duct was ligated prior to the injection showed an occurrence of a glandular secretion of the drug into the intestinal mucosa from the blood circulation. After oral administration, the radioactivity was found to be restricted very effectively to the gastrointestinal tract, indicating a limited absorption from the intestine, and the most part of the absorbed drug to be cleared back into the intestinal tract via the bile. These characteristics are discussed with respect to the structural characteristic of quaternary ammonium structure and the possible relations are pointed out between the sites of the drug accumulation and those of the pharmacological action where the drug has been clinically applied as a peripheral anti-spasmodic agent with a lower side effect than has atropine.
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