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Volume 91 (1988)
- Issue 6 Pages 335-
- Issue 5 Pages 275-
- Issue 4 Pages 173-
- Issue 3 Pages 121-
- Issue 2 Pages 61-
- Issue 1 Pages 1-
Volume 91, Issue 5
Displaying 1-7 of 7 articles from this issue
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Hideki BESSHO, Yuji HARA, Yasuko KIMURA, Akihiro NARIMATSU, Daijiro HO ...1988 Volume 91 Issue 5 Pages 275-283
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSInhibitory effects of terazosin on the compensatory blood pressure responses to tilting were studied in conscious rabbits and spontaneously hypertensive rats (SHR). In rabbits, doses which reduced the mean blood pressure by 15 mmHg were 330 μg/kg, i.v., for terazosin and 42 μg/kg, i.v., for prazosin, while those which depressed the blood pressure responses to tilting by 30 mmHg were 180 μg/kg, i.v., for terazosin and 54 μg/kg, i.v., for prazosin. In SHR, almost equal decreases in the mean blood pressure (about 30%) were observed by 1 mg/kg prazosin, p.o., 20 mg/kg hexamethonium, i.p., 3 mg/kg hydralazine, p.o., or 3 mg/kg nicardipine, p.o. In these conditions, prazosin and hexamethonium markedly depressed the blood pressure responses to tilting, whereas hydralazine and nicardipine showed little effect. The results with these antihypertensive drugs closely paralleled the established orthostatic profiles seen clinically. In this SHR tilting model, when the mean blood pressure was reduced by 15%, prazosin significantly depressed the tilting reflexes; however, terazosin produced no depression. Considering the dose ratio of terazosin to prazosin for antihypertensive effects and inhibitory effects on the tilting reflexes, the orthostatic liability of terazosin was about 3 times as low as that of prazosin. On the basis of these results, it is expected that terazosin causes less orthostatic hypotension than prazosin in clinical use.View full abstractDownload PDF (5342K) -
Kaname MIYAMOTO, Ieharu HISHINUMA, Jun-ichi NAGAKAWA, Naoko NAGAOKA, T ...1988 Volume 91 Issue 5 Pages 285-293
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESS4-(2-Succinimidoethylthio) phenyl 4-guanidinobenzoate (E-3123) potently inhibited trypsin, plasmin and thrombin with IC50 values of 3.9 × 10-8 M, 9.5 × l0-7 M and 1.9 × 10-6 M, respectively. Experimental acute pancreatitis was induced by injection of a mixture of trypsin and taurocholate into the pancreas in rats and rabbits or by an application of a closed duodenal loop in dogs. Intravenous infusion of E-3123 at 0.03 ?? 0.3 mg/kg in rats or at 0.3 ?? 3.0 mg/kg in rabbits reduced mortality after the induction of pancreatitis in a dose-dependent manner. Light microscopy of the pancreas in the E-3123-treated rabbits revealed marked decrease in cell necrosis and acinar cell vacuolation. Increase in plasma lipase activities associated with the progression of pancreatitis in rabbits was also reduced by the infusion of E-3123. In dogs with pancreatitis, increases in serum trypsin and lipase activities were significantly reduced by infusion of E-3123 at 1.0 and 3.0 mg/kg. The efficacies of E-3123 in the in vivo experiments were higher than those of nafamostat mesilate. These results show that E-3123 may possess suppressing effects on pathogenesis and development of acute pancreatitis.View full abstractDownload PDF (5970K) -
Masahiro SUNO, Akinobu NAGAOKA1988 Volume 91 Issue 5 Pages 295-299
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe effects of idebenone and various nootropic drugs on lipid peroxidation in rat brain homogenate were examined. Idebenone inhibited lipoperoxide (LPO) production in brain homogenate in a concentration-dependent manner, with an IC50 of 38 μM. The inhibition was strongly enhanced (about 100-fold) by adding succinate, a substrate in the mitochondrial respiration. The optimal concentration of succinate was 0.5 mM. Inhibition of lipid peroxidation in brain homogenate by various nootropic drugs in the presence or absence of succinate was then examined. Drugs added to the brain homogenate at 100μM in the absence of succinate inhibited LPO production in the order: idebenone > vinpocetine > bifemelane > indeloxazine > calcium hopantenate. However, when the drugs were added at 1 μM in the presence of succinate, only idebenone demonstrated inhibition. These results suggest that although almost all of the drugs tested inhibit lipid peroxidation in brain homogenate, only idebenone is activated by succinate, the other drugs being insensitive to this compound.View full abstractDownload PDF (3308K) -
Masaaki IZUMI1988 Volume 91 Issue 5 Pages 301-308
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSPhysiological significance of colocalization of enkephalin and adrenaline in the adrenal medulla was studied by examining pressor responses to concomitant administration of [D-Ala2, Met5]-enkephalin (100 μg/kg, s.c.) and l-adrenaline (50 μg/kg, s.c.) in adrenalenucleated rats. The adrenal medulla of Wistar-Imamichi rats was removed at 3 weeks (3WAdMx) or 12 weeks (12WAdMx) of age. Control rats were sham-operated. Blood pressure (BP) was measured by the tail-cuff method. 1) A single s.c. injection of enkephalin induced a marked rise in BP at 10 min in control male and female and the 3WAdMx-male rats, whereas the 3WAdMx females showed only a 5 mmHg increase at its maximum in the BP following enkephalin administration. 2) In the control male and female rats, the 5 min pretreatment with enkephalin enhanced the pressor response to l-adrenaline, and the pressor effect of enkephalin plus l-adrenaline was suppressed by pretreatment with naloxone (2.5 mg/kg, s.c.). On the other hand, in the 3WAdMx male and female rats, the pressor effect of l-adrenaline was almost completely suppressed by pretreatment with enkephalin. Moreover, pretreatment with naloxone resulted in an increase in BP after administration of enkephalin plus l-adrenaline in the 3WAdMx female rats. 3) In contrast to the control female rats, the pressor effect of enkephalin plus adrenaline was also enhanced by pretreatment with naloxone in the 12WAdMx female rats. The results suggest that the lack from immature age of catecholamine and enkephalin which originate from the adrenal medulla appears to alter the responsiveness of the BP regulatory system to exogenous catecholamine and enkephalin in the rat.View full abstractDownload PDF (4805K) -
Hideki TAKASE, Katsue IMANISHI, Osamu MIURA, Eizaburou YUMIOKA, Hirosh ...1988 Volume 91 Issue 5 Pages 309-317
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe effects of OGT, SST, AS and DST on gastric acid secretion stimulated by histamine, pentagastrin, carbachol and 2-deoxy-D-glucose (2-DG) were studied in the perfused stomach of anesthetized rats, and these effects were compared with those of cimetidine, 16, 16-dimethyl-prostaglandin E2(DMPGE2) and atropine. OGT and SST showed little or no effect on the acid secretion induced by histamine or carbachol at doses of 100 mg/kg, whereas the former showed a moderate inhibition and the latter showed a marked one against pentagastrin-stimulation. AS and DST had no effect on the acid secretion induced by carbachol at doses of 100 mg/kg, whereas they showed a moderate inhibition against histamine-stimulation, and the latter showed a significant inhibition against pentagastrin-stimulation. Further, each of the above four drugs showed a significant effect on 2-DGstimulation. Cimetidine (1 ?? 10 mg/kg) inhibited gastric acid secretion stimulated by histamine, pentagastrin, carbachol or 2-DG in a dose-dependent manner. Similarly, DMPGE2 (10 μg/kg) strongly inhibited acid secretion induced by the four secretagogues. Atropine (50 μg/kg) inhibited acid secretion induced by carbachol or 2-DG, but not that by histamine or pentagastrin. These results suggest that OGT, SST, AS and DST clearly affect the mechanism of gastric acid secretion, and the site of action of OGT may differ from those of SST, AS and DST.View full abstractDownload PDF (6495K) -
Hideki TAKASE, Katsue IMANISHI, Osamu MIURA, Eizaburou YUMIOKA, Hirosh ...1988 Volume 91 Issue 5 Pages 319-324
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe effects of OGT, SST, AS and DST on ethanol and aspirin-induced gastric hemorrhagic lesions in rats were studied in comparison with those of sucralfate, 16, 16-dimethyl-prostaglandin E2 (DMPGE2) and cimetidine. 1) OGT given orally at doses of 25 ?? 250 mg/kg protected gastric mucosa from injury induced by ethanol or aspirin. 2) SST prevented the appearance of aspirin-induced lesions at doses more than 25 mg/kg, and ethanol-induced lesions at 250 and 500 mg/kg. 3) AS and DST inhibited aspirin-induced lesions at more than 250 mg/kg and inhibited ethanol-induced lesions at 500 mg/kg. 4) Sucralfate (500 mg/kg) significantly prevented ethanol- and aspirin-induced lesions. DMPGE2 significantly inhibited ethanol-induced lesions at doses more than 0.1 μg/kg, and it inhibited aspirin-induced lesions dose-dependently at doses ranging from 0.1 to 5 μg/kg. Cimetidine significantly inhibited aspirin-induced lesions at doses of 10 ?? 250 mg/kg and inhibited ethanol-induced lesions at doses of 100 and 250 mg/kg. These results suggest that OGT, SST, AS and DST have a prophylactic effect on ulcerogenics, and the potency of OGT may be superior to those of SST, AS and DST.View full abstractDownload PDF (4234K) -
Tetsuo KUZE, Hideto MIYAZAKI, Tetsuro TANEIKE1988 Volume 91 Issue 5 Pages 325-334
Published: 1988
Released on J-STAGE: February 23, 2007
JOURNAL FREE ACCESSThe disposition of theophylline (aminophylline) administered either parenterally or orally to anesthetized dogs was studied. Pharmacokinetics of theophylline (8.2 mg/kg, n=10) following intravenous administration could be analyzed by a two-compartment open model. The half-time (T1/2β) of theophylline was 5.63±0.83 hr, and the volume of distribution (Vd) was 0.73±0.04l/kg. The elimination rate constant was 0.37±0.05 hr-1. Two metabolites of theophylline were isolated from urine and identified as 3-methyl xanthine (3-MX) and 1, 3-dimethyl uric acid (1, 3-DMU) by HPLC. The dogs excreted about 85% (n=4) of the dose in urine in 24 hr. The majority (2/3) was excreted as changed theophylline, i.e., 3-MX 40.2±3.5% and 1, 3-DMU 26.2±4.3%, while unchanged theophylline amounted to 18.2±2.4%. Absorption of theophylline (8.2 mg/kg, n=5) administered intramuscularly was good as indicated by its high bioavailability (101.9±6.5%), but the value of bioavailability was low in oral administration (72.8±11.8%, n=5). The percentage of protein binding (about 44%, n=3 ?? 7) did not change by increasing the serum concentration (8.2 ?? 24.6 μg/ml).View full abstractDownload PDF (6616K)
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