The pharmacokinetics in maternal-fetal unit of ¹⁴C-p-phenyl benzoic acid was studied in intact and bile duct-cannulated pregnant rats following the intravenous administration. The half life of the maternal blood level was shortened by bile duct-cannulation. However, the effect of bile duct-cannulation on the decay curve of fetal blood level was not recognized. There was no difference in the distribution pattern from whole body autoradiogram and tissue binding between mother and fetus. PPBA level in fetal plasma was different from that in maternal central and peripheral compartment based on pharmacokinetic analysis. The glucuronide levels in fetal intestine and amniotic fluid increased with time. The levels of PPBA and its glucuronide in fetal tissues on the 18th day of gestation were lower than the corresponding levels on the 20th day of gestation. The elimination rate of the glucuronide in amniotic fluid was higher on the 18th day of gestation.

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The change in the pharmacokinetic character of p-phenyl bezoic acid (PPBA) in developing fetus of rat was investigated by a constant infusion of ¹⁴C-PPBA. PPBA level in tissues increased with the day of gestation. The hepatic clearance for PPBA showed the increase with the stage of development. The excretion of the glucuronide from liver into bile increased with the stage, remarkably between the 19th and 21st day of gestation. The developmental profile of UDP-glucuronyltransferase activity in hepatic microsomes of fetus resembled that of the hepatic excretory function for the glucuronide. The glucuronide level in the amniotic fluid increased with the day of gestation, remarkably between the 19th and 21st day of gestation. The elimination rate of the glucuronide from amniotic fluid determined by intraamniotic injection of the glucuronide decreased linearly with the day of gestation.

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We studied the influence of rat renal prostaglandin on the effect of vasopressin, in vivo. In water-loaded rats, vasopressin induced a dose-related increase in total urinary prostaglandin E and prostaglandin F excretion and a decrease in total urine output. Urine excretion, which peaked in water-loaded controls during the first 2h after loading, was suppressed in vasopressin-treated rats, however, their urinary prostaglandin E excretion was markedly enhanced. This increase in urinary prostaglandin E was suppressed by the simultaneous administration of indomethacin, and the 3-6h post-administration peak in urine output of vasopressin-treated rats was inhibited. In hypophysectomized rats, urine excretion increased gradually after surgery, however, urinary prostaglandin E excretion decreased. Based on our present findings, we suggest that prostaglandin E produced in the rat kindney modulate the ranal response to vasopressin.

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We measured the cyclic nucleotides levels of the rat vas deferens surgically denervated in order to investigate the relationship between denervation supersensitivity and cyclic nucleotides. Two days after denervation, cyclic AMP slightly decreased to 90.4% of control and cyclic GMP also decreased but not significantly. So it is assumed that almost all of the cyclic nucleotides are not neurogenic but myogenic. When the rat vas deferens was incubated with l-norepinephrine 10^-4M for 3 min, the cyclic GMP level in the vas deferens denervated for 7d was significantly higher than that in the intact specimen, and the cyclic AMP level in the intact one was almost the same as in the denervated preparation. Denervation produced leftward shift of the dose response curve in cyclic GMP level to l-norepinephrine. After incubation with acetylcholine (10^-4M), however, cyclic GMP and cyclic AMP levels in the denervated vas deferens were almost the same as in the intact one. Therefore, it is suggested that cyclic nucleotides don't relate to the induction of nonspecific supersensitivity by denervation in the rat vas deferens.

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Concanavalin A (ConA)-bound tumor cell vaccine of methylchoranthrene-induced fibrosarcoma (Meth 1) induced tumor-specific immunoprophylactic and immunotherapeutic response against an inoculum of live Meth 1 cells in histocompatible animals. ConA-free Meth 1 vaccine induced much less response under the identical experimental conditions. Immunotherapeutic potency of ConA-bound Meth 1 vaccine was enhanced by levamisole, and 37% of the animals inoculated with 10⁴ live Meth 1 cells at day 0 were cured when they were administered 10⁶ cells of ConA-bound Meth 1 vaccine at days 1 and 8 and 0.63 mg/kg levamisole at days 1, 2 and 3. Delayed administration of levamisole at days 8, 9 and 10 was less effective than the earlier administration, but still produced a 17% cure of Meth 1-bearing animals when combined with ConA-bound Meth 1 vaccine. Immunotherapeutic response under these regimens was further enhanced by mitomycin C, and approximately 60% of the animals inoculated with 10⁵ Meth 1 cells were cured when three agents were administered at the defined intervals. These results suggest the feasibility of the regimen in which the therapeutic response induced by immunotherapeutic agents is further enhanced by the selected chemotherapeutic agents.

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The absorption, distribution, excretion, metabolism and protein binding of orally administered tritium-labeled aspirin-isopropylantipyrine (AIA) were demonstrated in rats. ³H-AIA having 0.1μCi/mg of specific activity and 93.2% of radiochemical purity was prepared by the Wilzbach's method. When ³H-AIA was administered orally to rats, about 20% of the given ³H was absorbed from gastro-intestinal tracts in 30 min and about 50% in 3h, 72% of the dose was excreted in the feces and urine during 5d, and 10% was excreted in the bile in 24h. The highest accumulation of ³H in most organs was found in one to three hr after oral administration and ³H was concentrated in teh liver. The major metabolites excreted in urine within 24h after administration were salicylic acid-isopropylantipyrine (SIA) sulfate (57.7%) and SIA glucuronide (30.5%). The amount of free SIA excreted in urine was 1.2%. The carboxylamide bond of AIA was never cleaved in vivo to give salicylic acid and 3-aminomethylisopropylantipyrine. About 58% of ³H in blood 1h after the administration was bound with serum protein.

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Treatment of rats with 1-m-tolueneazo-2-naphthol (mTAN) caused marked increase in liver weight, microsomal 7-ethoxycoumarin O-deethylase activity and cytochrome P-450 content, with 2 nm hypochromic shift in CO difference spectrum. It decreased NADPH-cytochrome c reductase and aminopyrine N-demethylase activities. Treatment of 3-methylcholanthrene nonresponsive DBA/2 strain of mice with this azo compound resulted in a limited (1.5 fold) induction of cytochrome P-450 compared to 2.5 fold induction in responsive C57BL/6 strain of mice. The major species of liver microsomal P-450 from m-TAN treated rats was purified. This species of P-450 has a Solet peak at 416 nm in the absolute oxidized sprectrum, 410 nm in the reduced spectrum and 447 nm in the spectrum of ferrous P-450-CO complex. This species of P-450 is spectrally indistinguishable from cytochrome P-448 induced by 3-methylcholanthrene. As an inducer of cytochrome P-450, m-TAN is similar to 3-methylcholanthrene with its potency equals to or exceeding that of 3-methylcholanthrene. It differs in that it causes marked increase in liver weight and decrease in NADPH-cytochrome c reductase activity.

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Induction of a delayed type hypersensitivity to carrageenin in mice was investigated with successful results. Male ddY/s mice were immunized with 1 mg of carrageenin in 100μl of Freund's complete adjuvant-saline (1 : 1) emulsion and challenged 10d after the immunization on their footpads with either 10 or 40μg of the antigen in 2.5μl of Freund's incomplete adjuvant-saline (1 : 1) emulsion. The mice exhibited a strong allergic footpad reaction at 24-48h after the challenge injection. The footpad reaction was successfully transferred with spleen cells. Non-steroidal antiinflammatory drug, indomethacin, and steroidal antiinflammatory drug, dexamethasone, suppressed the delayed type hypersensitivity reaction.

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Effect of a potent cytochrome P-448 inducer, 1-m-tolueneazo-2-naphthol (m-TAN) on hepatic microsomal UDP-glucuronyl-transferase (UDPGT) activity was studied. The UDPGT activity reached the maximum level on the fifth day after either a single injection or consecutive daily administrations. The UDPGT activities towards p-nitrophenol, 1-naphthol and chloramphenicol were increased up to 6, 2.5 and 1.8 folds of control levels respectively, in microsomes from m-TAN treated rats. 3-Methylcholanthrene, on the other hand, caused 4 and 2 fold increase in UDPGT activities towards p-nitrophenol and 1-naphthol respectively, but did not cause significant increase in UDPGT activity towards chloramphenicol. It is concluded that m-TAN is a new, potent inducer of UDPGT activity with its potency exceeding that of 3-methylcholanthrene and the pattern of induction, a little different from that of 3-methylcholanthrene.

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Rats were intraperitoneally immunized with bovine γ-globulin (BGG) emulsified in incomplete Freund's adjuvant. Intestinal absorption of salicylic acid from the rat small intestine was examined by means of in situ recirculation technique. The disappearance of salicylic acid from the luminal solution was significantly decreased in rats challenged intravenously with BGG compared to saline as control. A significant decrease in absorption of salicylic acid was noted in rats immunized twice and three times, but not in rats immunized only once. The effect was maintained for at least 5 weeks after the third immunization, whereas it disappeared within 10 weeks. In normal rats, the decreased absorption of salicylic acid by the intravenous challenge with BGG was hardly observed at all. These findings suggest that the intestinal absorption of salicylic acid may be affected by systemic anaphylaxis in actively immunized rats.

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Effects of calcium blockers and Mn on the mechanical response of the isolated rat iris sphincter and the dilator were investigated. The contraction of the sphincter in response to acetylcholine, the contraction of the dilator in response to norepinephrine and the relaxation-contraction of the dilator in response to acetylcholine and also resting tone of dilator muscle were strongly dependent to external Ca concentration to different extents, while these responses and the tone were scarcely affected by calcium blockers, D-600, diltiazem (all 1μM), or nitroprusside Na (0.1mM). In depolarized sphincter muscle (in the presence of atropine and phentolamine), the contraction induced by externally added Ca was reduced moderately by the Ca-blockers but this effect was far weaker than that expected from their effect on other smooth muscles. Mn (0.3 mM) moderately reduced the calcium contraction of depolarized sphincter. In depolarized dilator muscle, the contraction induced by Ca was not inhibited effectively by any of these Ca blockers but was moderately reduced by Mn. It is suggested that the rat iris muscles are resistant to "organic Ca-blockers" but sensitive to Mn, an "inorganic Ca-blocker".

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The protective effect of flunarizine against cerebral hypoxia-anoxia was investigated with various experimental models in mice and rats. The effect of flunarizine was compared with those of cinnarizine, verapamil and pentobarbital. The oral treatment of animals with flunarizine resulted in a consistent and long-lasting protection against cerebral hypoxia-anoxia in all the models examined : Cytotoxic anoxia by KCN injection, hypercapnic anoxia induced by stopping artificial respiration, hypobaric hypoxia and normobaric hypoxia. The minimal effective dose of flunarizine was 1 to 20 mg/kg. The activity of flunarizine was 4 to 30 times as potent as that of cinnarizine and pentobarbital. Verapamil showed little or no protective effect. The mode of action of flunarizine was different from that of pentobarbital, which showed protection at anaesthetizing doses. These results indicate that flunarizine possesses a universal protective effect against cerebral hypoxia-anoxia, though the mechanism involved remains to be clarified. Hence, it is suggested that flunarizine might exert a beneficial effect on oxygen insufficiency of the brain resulting from cerebral ischemia.

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