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Biomedical subjects

S Kanai

Publications and source records attributed to S Kanai.

At least 163 records · Page 9Linked to original sources
PubMed1984

The digitoxin metabolism in isolated hepatocytes from young and old male Wistar rats.

The metabolism of digitoxin (Dt3) in isolated hepatocyte preparations was studied in young (3-mth-old) male and female rats, young castrated (3-mth-old) male rats and old (22- to 28-mth-old) male rats. When hepatocytes were incubated with [3H]Dt3, the predominant metabolite of Dt3 was digitoxigenin-bis-digitoxoside (Dt2) which was 70-90% of the total metabolites in the three male rat groups. Only in the young female rat group was the proportion of Dt2 (40%) slightly exceeded by that of digoxigenin-bis-digitoxoside (Dg2) (50%). A kinetic analysis for Dt3 degradation velocity obtained from studies using different Dt3 concentrations in old male rats yielded a Vmax of only 21% of the young value. In young castrated males, the Vmax also decreased to 13% of the young non-castrated males, which is approaching the young female value. The changes were primarily due to the decline of Dt2 formation velocity in these groups. Apparent Km values also decreased with both castration and aging. The plasma testosterone levels which were much higher in young male rats than in female rats became significantly lower in young castrated rats as well as in old male rats. The results suggest that apparent decreases in Vmax and Km values observed in old male rats for Dt3 metabolic degradation may be at least partly through the steroidal hormone control, presumably, the decline of androgenic induction during aging.

Aging↗
PubMed1984

Increased anticonvulsant effect of phenytoin in aging BDF1 mice.

The anticonvulsant effect of phenytoin was examined in BDF1 mice of both sexes and various ages (6, 12, 24 and 30 months old) using the abolition of the tonic hindlimb extensor component of maximal electroshock seizure as the index. The minimal effective plasma concentration of phenytoin was significantly lower in 24- and 30-month-old mice compared with young adult (6 month old) mice. Similarly, all older groups (24 and 30 month old, both sexes) showed significantly lower minimal effective brain concentrations compared with respective younger (6 and 12 month old) animal groups. Studies using nearly 2-fold different intensities of electroshock (30 and 55 mA) showed almost identical results. The results provide evidence that, in adult mice, the brain becomes more sensitive with age to phenytoin with regard to its anticonvulsant effect.

Aging↗
PubMed1983

The bile flow and biliary excretion of ursocholate in the rat.

Several studies reported that ursodeoxycholate (but not its conjugates), when administered intravenously, increased the biliary bicarbonate concentration in the rat (1-3). At the same time, a complete dissociation between bile flow and the bile salt excretion rate was produced in the second hr of infusion (2). In order to examine whether this property was due to the 7 beta-hydroxy group in its molecular structure, the choleretic property of ursocholate (3 alpha, 7 beta, 12 alpha-trihydroxy-5 beta-cholanoic acid) was investigated in male Wistar rats. Immediately after the start of iv infusion of ursocholate at a rate of 1.2 mumole/min/100 g b. wt., both the bile flow and bile salt excretion rate began to increase. However, unlike with ursodeoxycholate, the bile salt excretion rate continued to be high in the second and third hr of infusion, while the bile flow rate gradually increased. Furthermore, the bicarbonate concentration in the bile fell slightly 10 min after the start of ursocholate infusion. Although the concentration tended to return to the baseline value before the bile salt infusion in the later period of observation, no significant increase in bicarbonate concentration was observed during the whole observation period. These properties were quite similar to those of cholate rather than those of ursodeoxycholate. However, a cholate infusion at the same rate of 1.2 mumole/min/100 g b.wt. caused a cholestasis as early as 20 to 30 min after the start of an infusion. These results suggest that the previously reported properties of ursodeoxycholate (that it causes a complete dissociation between the bile flow and bile salt excretion rate in the second hr and that it increases the biliary bicarbonate concentration) were not due to the 7 beta-hydroxy group in its steroidal structure, and that the choleretic property of ursocholate is similar to its 7 alpha-hydroxy epimer, cholate. However, the much lower cytotoxicity of ursocholate compared to cholate appears to be due to the 7 beta-hydroxy group that ursocholate has.

Animals↗
PubMed1983

Glycoursodeoxycholate is as effective as tauroursodeoxycholate in preventing the taurocholate-induced cholestasis in the rat.

A combined infusion of taurocholate (TC) and glycoursodeoxycholate (GU) resulted in a longer choleretic period and a significantly higher excretion of TC compared with the infusion of TC alone, as has been previously observed for the combined infusion of tauroursodeoxycholate (TU) and TC in the rat. It was concluded that GU is as effective as TU in preventing TC induced cholestasis in this species.

Animals↗
PubMed1983

[Clinical evaluation of cefbuperazone in complicated urinary tract infection].

Cefbuperazone, a new cephamycin antibiotic, was used in 13 complicated UTI cases. The drug was given at a dose of 1 g in 100 ml of physiological saline solution twice a day for 5 - 14 days and judged for its clinical effect in 11 cases on days 5 - 7 according to the criteria of the UTI committee. Overall clinical efficacy was excellent in 3 cases, moderate in 2 cases and poor in 6 cases, the effectiveness rate was 45.5%. In laboratory findings, slightly elevated transaminase and A1-P were observed in 2 cases and 1 case, respectively.

Adult↗
PubMed1983

Interactions between different bile salts in the biliary excretion of the rat.

In rats the simultaneous infusion of tauroursodeoxycholate and taurocholate resulted in a longer choleretic condition with higher total bile salt and taurocholate excretion rates as compared to taurocholate infusion alone. A similar but weaker response was observed when taurodehydrocholate was simultaneously infused instead of tauroursodeoxycholate. The taurolithocholate induced cholestasis was most markedly prevented when taurocholate, rather than tauroursodeoxycholate, was simultaneously infused. It was suggested that the effect of tauroursodeoxycholate on the biliary excretion of taurocholate appears to differ from that of taurocholate on taurolithocholate excretion.

Animals↗
PubMed1982

Tauroursodeoxycholate prevents taurocholate induced cholestasis.

The nature of transport pathway(s) for the biliary excretion of taurocholate and tauroursodeoxycholate was examined by comparing the biliary transport maximum (Tm) value for taurocholate during the infusion of taurocholate alone with that of taurocholate combined with tauroursodeoxycholate. The combined infusion of tauroursodeoxycholate resulted in an appreciable excretion of tauroursodeoxycholate while the excretion rate of taurocholate was not reduced in comparison with the Tm value of taurocholate alone. Furthermore, the Tm state of taurocholate was maintained for a much longer period with the simultaneous infusion of tauroursodeoxycholate than by the infusion of taurocholate alone. The cholestasis usually produced by the excess infusion of taurocholate was also prevented when tauroursodeoxycholate was simultaneously infused. Since plasma taurocholate concentration was not significantly different from the two rat groups, the results suggest the presence of the facilitative interaction of tauroursodeoxycholate with the taurocholate excretion.

Animals↗
PubMed1982

Biliary excretion of digitoxin and its metabolites in young and old male Wistar rats.

The biliary excretion of digitoxin (Dt3) and its metabolites were compared between young (3-month-old) and old (25-month-old) male Wistar rats after an iv injection of [3H]Dt3 (0.03 mg/100g body weight) for 2 hrs. The 2-hr. total biliary recovery of iv injected radioactivity (percent of the dose) was two times lower in old rats (7.40 +/- 1.36% mean +/- SD) compared with young rats (14.74 +/- 4.10%). This difference was primarily due to the decrease in the excretion of Dt3 metabolites in the bile, while the excretion of the parent drug, Dt3 was 1.3 times higher in old rats. Among various Dt3 metabolites in the bile, digitoxigenin bis-digitoxoside (Dt2), digoxigen bis-digitoxoside (Dg2), and polar (conjugated) metabolites were major components, which all decreased with age. In accord with the decreased excretion of the radioactivity in the bile of old rats, the plasma disappearance of radioactivity was generally slower in old animals compared with young ones, yielding significantly higher plasma levels at different times of observation. Despite the increase in plasma radioactivity, the radioactivity concentration in the liver 2 hrs. after the injection was almost equal between the two age groups. It is suggested that at least in this rat strain and sex the biliary excretion of Dt3 metabolites was markedly age-dependent, presumably due to the decreased capacity of the liver to biotransform Dt3 with age. Furthermore, the lower liver plasma radioactivity ratio in old animals suggested the possibility that the distribution of Dt3 in the liver may also decrease with age.

Aging↗
PubMed1981

The effect of bucolome on the blood circulation of splanchnic organs in rats with and without pentobarbitone anesthesia.

Using carbonized microspheres, either 15 microns or 50 microns in diameter and labeled with 85Sr, 51Cr or 141Ce, the effect of bucolome (1-cyclohexyl-5-n-butyl-2-, 4, 6-trioxoperhydropyrimidine), a non-steroid anti-inflammatory agent and potent choleretic, on the splanchnic blood circulation was studied in rats with and without pentobarbitone sodium anesthesia. Pentobarbitone sodium caused a significant increase in the distribution of cardiac output in the major splanchnic organs, in particular in the small and large intestines. An i.p. injection of bucolome (20 mg/100 g) produced a significant increase in the cardiac output distribution in the small intestine, and a significant decrease in the pancreatic fraction in both rat groups with and without pentobarbitone anesthesia, in spite of the large increase in the base-line values caused by anesthesia.

Anesthesia↗
PubMed1981

The effect of bucolome on the biliary excretion of colchicine in the rat.

The biliary excretion of intravenously administered [14C]-colchicine was compared for 2 hr between control rats and rats treated with bucolome (5-n-butyl-1-cyclohexyl-2,4,6-trioxoperhydropyrimidine, 200 mg/kg, i.p.). In the first 10-min period after colchicine injection, the bile flow rate was 70 percent higher (p less than 0.01) in bucolome treated rats than in control rats. The bile flow rate in bucolome treated rats gradually decreased and 1 hr later, the difference between control and bucolome treated rats was no longer significant (p greater than 0.05). The percent of the administered colchicine dose recovered in the first 2 hr in bucolome treated rats given an i.v. injection of 70 or 700 micrograms/kg colchicine was significantly higher than in control rats. The difference was primarily due to the higher excretion rate in the former group in the first 10-min period. When the biliary radioactivity was examined by thin layer chromatography, it was found that the excretion of free colchicine was significantly increased in bucolome treated rats which accounted for the observed increase in the biliary excretion of radioactivity in bucolome treated rats. It was concluded that bucolome is effective in increasing the biliary excretion of free colchicine.

Animals↗
PubMed1979

Fibrin suspension as a substrate fop plasmin: determination and kinetics.

Fibrin polymers formed from fibrinogen with thrombin in the presence of EDTA were suspended in a medium containing glucose, arabic gum and imidazole-HCl buffer and were sonicated at 20 kHz for 20 min to make a suspension containing fibrin particles of small size. The fibrin suspension was used as a substrate of plasmin for determining the enzymic activity of plasmin and plasminogen activated with urokinase. The kinetic study on the reaction of the fibrin particles with plasmin in the presence and the absence of fibrinogen revealed that Km value of fibrin for plasmin is 4.2 x 10(-7) M and the Ki value of fibrinogen is 1.2 x 10(-5) M.

Electrophoresis, Disc↗