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Volume 42 (1986)
- Issue 4 Pages 457-
- Issue 3 Pages 333-
- Issue 2 Pages 153-
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Volume 42, Issue 3
Displaying 1-15 of 15 articles from this issue
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Takashi MATSUBARA, Shigemi OTSUBO, Ayako OGAWA, Joji OKAMOTO, Toshio Y ...1986 Volume 42 Issue 3 Pages 333-343
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSSeveral β-lactam antibiotics, especially those containing N-methyl-tetrazolylthiomethyl groups at the 3-position of the cephalosporin nucleus, affect the alcohol-metabolizing system in rats. These effects were compared those with disulfiram, well-known as a potent inhibitor of aldehyde dehydrogenase (ALDH). Both disulfiram and antibiotics containing the N-methyltetrazolylthiomethyl group inhibited both mitochondrial low Km ALDH and acetaldehyde oxidation in rat livers. The high Km ALDH and alcohol dehydrogenase activities in livers were not affected by these treatments. When ethanol was given to rats pretreated with disulfiram or these antibiotics, the blood acetaldehyde concentration increased markedly concomitant with a decrease in activity of the low Km ALDH. Administration of N-methyltetrazolethiol alone suppressed the low Km enzyme activity and also increased the blood acetaldehyde level; both effects were pronounced and observed several hours after administration. β-Lactam antibiotics without N-methyltetrazolethiol in their molecule did not affect the liver mitochondrial enzyme activity or the blood acetaldehyde level.View full abstractDownload PDF (619K) -
Kenji TAKAMI, Kazuya HASHIMOTO, Shuji UCHIDA, Masaya TOHYAMA, Hiroshi ...1986 Volume 42 Issue 3 Pages 345-350
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSThe effect of calcitonin gene-related peptide (CGRP) on the cyclic nucleotide level in isolated mouse diaphragm was investigated. CGRP at concentrations of up to 1 μM caused dose-dependent increases in cyclic AMP levels but had no effect on cyclic GMP levels. At 1 μM, CGRP increased cyclic AMP levels by about 2.7-fold. Moreover, in the presence of phosphodiesterase inhibitor (Ro 20-1724), CGRP still caused even greater dose-dependent increases in cyclic AMP levels. Even in the presence of propranolol, a beta-adrenergic antagonist, CGRP stimulated increased cyclic AMP levels. In addition, specific binding of CGRP was observed in mouse diaphragm. All these results suggest that CGRP increases intracellular cyclic AMP levels via a CGRP receptor but not the betaadrenergic receptor.View full abstractDownload PDF (275K) -
Toshizo TANAKA, Chiyoko INAGAKI, Koji MATSUDA, Shuji TAKAORI1986 Volume 42 Issue 3 Pages 351-359
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSStudies were performed to characterize ethacrynic acid (EA) highly sensitive Mg2+-ATPase isolated from microsomal fractions of the rat brain. The functional molecular sizes of the EA highly sensitive and EA less sensitive Mg2+-ATPases, estimated by a radiation inactivation method, were 480 and 80 kDa, respectively. An anion transport inhibitor, 4-acetamido-4'-isothiocyanostilbene2, 2'-disulfonic acid (SITS) inhibited the EA highly sensitive Mg2+-ATPase activity. The type of inhibition was uncompetitive with respect to ATP, and the inhibition was suppressed by anions such as Cl-, Br- and I-. Chloride ions stimulated enzyme activity with an increase in Vmax, but not in Km, for ATP. Anions tested also increased the enzyme activity in the following order of decreasing potency: Cl- >Br->CH3COO-=I->SO42-=HCO3->SO32-. These results suggest that EA highly sensitive Mg2+-ATPase is a relatively large molecule with anion-sensitive sites that affect the ATP hydrolyzing activity and the SITS binding capacity through anions, with Cl- being the most potent.View full abstractDownload PDF (496K) -
Mayumi MORI, Hiromi TSUSHIMA, Tomohiro MATSUDA1986 Volume 42 Issue 3 Pages 361-369
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSEffects of dibutyryl-cyclic AMP (db-cAMP) and cyclic AMP (cAMP) microinjected into the hypothalamic supraoptic nucleus (SON) which contains the neurons synthesizing and releasing antidiuretic hormone upon the outflow and the osmotic pressure of urine and the other visceral functions were investigated in water-loaded rats anesthetized with ethanol. When microinjected into the SON the dibutyryl analog of cAMP induced dose-dependent antidiuretic effects without significant effects on any other visceral functions. Dibutyryl-cAMP was much more effective than CAMP; The ED50 value for db-cAMP was approx. 200 nmol versus more than 500 nmol for cAMP. The time course of the antidiuretic effects was relatively slow with minimal urine outflow appearing only after more than 1 /2 hour post-injection. The effects induced by db-cAMP demonstrated tachyphylaxis and were partially inhibited by pretreatment with atropine or theophylline, which suggests that the antidiuretic effects were mediated through muscarinic and adenosine receptors present in the nucleus.View full abstractDownload PDF (482K) -
Yasushi YAMAZOE, Miki SHIMADA, Tetsuya KAMATAKI, Ryuichi KATO1986 Volume 42 Issue 3 Pages 371-382
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSHypophysectomy decreased the content of a male specific cytochrome P-450, P-450-male, in male rats, while it expressed P-450-male and completely depressed a female specific cytochrome P-450, P-450-female, in female rats. Intermittent injections of human growth hormone (GH), which mimic the secretion in males, restored P-450-male in hypophysectomized (Hypox) male rats and partially restored P-450-female in Hypox female rats. Continuous infusion of GH, which mimics the female secretion pattern, into Hypox male rats caused a further decrease in P-450-male content, and it caused the expression of P-450-female. In Hypox female rats, the same treatment depressed P-450-male and expressed P-450-female to the level of an intact female. These results indicate that the diurnal changes in the pattern of serum growth hormone level regulate the expression of P-450-male and P-450-female. The activities of testosterone 2α- and 16α-hydroxylases were closely correlated to P-450-male content with the correlation coefficients (r) of 0.955 and 0.929, respectively. Benzo(a)pyrene hydroxylation was also correlated to P-450-male content (r=0.850). Aminopyrine N-demethylation and propoxycoumarin O-depropylation were correlated to less extents (r=0.692 and r=0.720), while aniline hydroxylation and O-ethylresorufin O-deethylation were not correlated to P-450-male content. These results indicate that testosterone 2α and 16α-hydroxylations are closely dependent, but the metabolism of a variety of drugs are dependent to different extents on P-450-male in rat liver microsomes.View full abstractDownload PDF (629K) -
Hironori TANAKA, Shigeru UEKI, Tomochika OHNO, Koji TAKEUCHI, Susumu O ...1986 Volume 42 Issue 3 Pages 383-396
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSMepirizole (60 and 200 mg/kg) administered s.c. induced damage in the surface epithelial cells of the rat proximal duodenum as early as 2 hr after the treatment. 16, 16-Dimethyl prostaglandin E2 (dmPGE2, 30 μg/kg) administered s.c. significantly protected the duodenal mucosa against mepirizole-induced damage for up to 6 hr. Gastric acid secretion in acute fistula preparations was significantly reduced 1 hr after administration of mepirizole (60 and 200 mg/kg). The secretion reverted to the control level 2 hr later. In the 60 mg/kg-treated group, however, there was a significant increase in the acid output for up to 6 hr. Duodenal HCO3-secretion stimulated with 10 mM HCl was significantly inhibited with mepirizole (60 and 200 mg/kg). Mepirizole (60 and 200 mg/kg) significantly increased the amount of acid in the duodenum for 2 to 6 hr after the treatment. dmPGE2 (30 μg/kg) significantly inhibited gastric acid secretion, stimulated duodenal HCO3-secretion, and reduced the increased amount of acid in the duodenum in response to mepirizole. Endogenous prostaglandin E2 and 6-keto prostaglandin F1α in the duodenal mucosa were significantly reduced by mepirizole (200 mg/kg) 1 to 2 hr later. Mepirizole-induced duodenal damage appears to be caused by the increased amount of acid in the duodenum.View full abstractDownload PDF (738K) -
Ryoji KOJIMA, Mikio ITO, Yoshio SUZUKI1986 Volume 42 Issue 3 Pages 397-404
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSEffect of latamoxef (LMOX) against tobramycin (TOB)-induced nephrotoxicity was studied in rats. Treatment with TOB (90 mg/kg/day, s.c.) alone resulted in marked increases in the activities of urinary enzymes such as lactate dehydrogenase, N-acetyl-β-D-glucosaminidase and lysozyme, urinary protein content and blood urea nitrogen, which peaked on the 7th or 10th day. The combination with LMOX (500, 1000 or 2000 mg/kg/day, s.c.) significantly suppressed increases in the parameters with TOB alone. The extent of this suppression roughly depended on the LMOX dosage. Although TOB alone caused pronounced histological changes such as extensive cortical proximal tubular cell necrosis, residual tubular basement membrane and cast formations in the renal cortex and medulla on the 7th day, these changes were apparently suppressed by combination with LMOX. In addition, intrarenal TOB concentrations in the rat given TOB alone were about 350, 500 and 1000 μg/g tissue wet weight at 3 hr, on day 3 and on day 5, respectively. On the other hand, there was a significant reduction (30-60%) in intrarenal TOB concentration by combination with LMOX. These results indicate that combination with LMOX obviously protects the rat kidney from TOB nephrotoxicity, and the protective effect may be partially due to suppression of intrarenal accumulation of TOB by LMOX.View full abstractDownload PDF (638K) -
Hiromu KAWASAKI, Ryuichi YAMAMOTO, Koichiro TAKASAKI1986 Volume 42 Issue 3 Pages 405-417
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSPossible mechanisms underlying the hypertensive response to intracerebroventricular (i.c.v.) or intravenous (i.v.) injection of clonidine were investigated in freely moving, normotensive rats. In conscious rats, clonidine (2-20 μg) injected i.c.v. caused a dose-dependent and long-lasting pressor response associated with bradycardia. A similarly long-lasting pressor response was induced following an initial rapid rise in mean blood pressure after i.v. bolus injections of clonidine (5-50 μg/kg). In pentobarbital-anesthetized rats, the prolonged pressor responses to i.v. and i.c.v. injected clonidine at high doses were significantly smaller than those in conscious rats. Low doses of clonidine caused only depressor responses which developed gradually. No significant changes in concentrations of plasma norepinephrine and epinephrine were found during the pressor period after i.c.v. injection of clonidine (20 μg). Systemic (2 mg/kg, i.v.) or central (100, ug, i.c.v.) pretreatment with phentolamine abolished only the prolonged pressor response to both i.c.v. (20 μg) and i.v. (50 μg/kg) injected clonidine. The prolonged pressor response to clonidine (20 μg, i.c.v.) was enhanced by pretreatment with hexamethonium (25 mg/kg, i.v.), methylatropine (1 mg/kg, i.v.) or atropine (1 mg/kg, i.v.) and it was not affected by pretreatment with saralasin (300 μg/kg and 25 μg/kg/ min, i.v.), d(CH2)5Tyr(Me)-arginine-vasopressin, a vasopressin antagonist (50 gig/kg, i.v.) or naloxone (1 mg/kg, i.v.). Neither adrenalectomy nor adrenal demedullation had an effect on the pressor response to clonidine (20 μg, i.c.v.). In adrenalectomized rats, systemic pretreatment with hexamethonium (25 mg/kg, i.v.) caused a potentiation of the pressor response to clonidine (20 μg, '.c.v.). These results suggest that clonidine induces the pressor response through activation of central α-adrenoceptors, probably the α2 subtype, without an increase in sympatho-adrenomedullary activity. It is speculated that the response may be mediated by vasoactive humoral substance(s).View full abstractDownload PDF (749K) -
Tsuyoshi KIHARA, Hiroshi KANETO1986 Volume 42 Issue 3 Pages 419-423
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSThe involvement of a catecholaminergic mechanism in the production of morphine analgesia and the development of tolerance to the effect has been suggested. Here, using various adrenergic blockers, the role of adrenergic function in the mechanism was examined. Phentolamine (α1 + α2-blocker, 10, 1 and 0.5 mg/kg), prazosin (α1 -blocker, 0.1 and 0.02 mg/kg), propranolol (β1 + β2-blocker, 10, 1 and 0.5 mg/kg), metoprolol (β1-blocker, 10 and 1 mg/kg) did not affect morphine analgesia, but dose-dependently suppressed the development of tolerance to morphine. Yohimbine (α2-blocker, 5 and 1 mg/kg) dose-dependently antagonized morphine analgesia in naive animals and delayed the development of tolerance to morphine. Pindolol (β1 + β2-blocker but is devoid of membrane stabilizing activity) suppressed the development of tolerance to morphine analgesia; however, d-propranolol, which possesses membrane stabilizing activity but lacks β-blocking activity, could not prevent the development of tolerance. Thus, the suppressive effect of propranolol on the development of tolerance is not due to membrane stabilizing properties. Not only the non-selective adrenergic blockers, phentolamine and propranolol, but also the selective blockers of each receptor subtype, prazosin and metoprolol, suppressed the development of tolerance. This fact may suggest the importance of the equilibrated state of adrenergic functions in the mechanism for the development of tolerance to morphine.View full abstractDownload PDF (257K) -
Hiroshi OZAKI, Hideaki KARAKI, Hiromi NAGASE, Norimoto URAKAWA, Hirosh ...1986 Volume 42 Issue 3 Pages 425-430
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSEffects of the toxic component of jellyfish (Carybdea rastonii) (pCrTX) on the smooth muscle tension of isolated rabbit thoracic aorta were examined. pCrTX, at concentrations higher than 10-7 g/ml, caused slowly developing tension that reached its maximum after about 1 hr. This contraction was partially inhibited by pretreatment of the tissue with phentolamine (5×10-6 M) or indomethacin (10-5 M). The contraction induced by pCrTX was partially inhibited by nicardipine (10-7 M) and markedly augmented by Bay k8644 (10-6 M). In low-Na+ solution, the rate of rise of the pCrTX-induced contraction was significantly reduced. Removal of external Ca2+ -inhibited the pCrTX-induced contraction by about 30%, while chlorpromazine, trifluoperazine, prenylamine and papaverine (10-4 M) completely inhibited the contraction. pCrTX itself did not cause any contraction in saponinskinned smooth muscle and had no effect on the Ca2+-induced contractile tension. It has been reported that pCrTX-induced contraction is attributable to the release of endogenous catecholamines and also to the increase in Ca2+ influx in smooth muscle (Azuma et al., 1986). The present results confirmed the previous suggestion and further suggested that a portion of the contraction is due to release of prostaglandin(s) and also to the direct effect on smooth muscle which is not dependent on Ca2+ influx.View full abstractDownload PDF (284K) -
Naohiko ONO, Yasundo YAMASAKI, Noriyuki YAMAMOTO, Akihiko SUNAMI, Hide ...1986 Volume 42 Issue 3 Pages 431-439
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSThe possible mechanism of the anti-inflammatory activity of proglumetacin maleate (PGM), a new indomethacin (IND) derivative interacting with arachidonic acid (AA) metabolism, was investigated to elucidate the contributions of PGM itself and its two major metabolites, desproglumideproglumetacin maleate (DPP) and IND. PGM caused much less inhibition of PGE2 formation by sheep seminal vesicle microsomes (IC50=310 μM) and TXB2 formation by a washed rabbit platelet suspension (IC50=6.3 μM) than IND. DPP also caused less inhibition of cyclooxygenase than IND. Moreover, PGM had less effect on sodium arachidonate (SAA)-induced rat platelet aggregation ex vivo and AA-induced sudden death in rabbits than IND. These results show that PGM has anti-inflammatory activity after its conversion to the active metabolite IND. However, the inhibitory effects of PGM and DPP were as strong as that of IND on SAA- or collageninduced rabbit platelet aggregation in vitro. These activities are considered to be associated with platelet membrane interaction. Moreover, unlike IND, PGM (IC50=1.5 μM) and DPP (IC50=16.3 μM) strongly inhibited 5-HETE formation by the cytosol of guinea pig polymorphonuclear leukocytes. This unique activity of PGM on 5-lipoxygenase may contribute to its anti-inflammatory activity.View full abstractDownload PDF (450K) -
Bong Ki KIM, Akemichi BABA, Heitaroh IWATA1986 Volume 42 Issue 3 Pages 441-446
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSIndirect stimulation via the sciatic nerve, 10 or 100 Hz stimulus trains of 1 sec duration, applied every 3 sec, 8 hr/day for 1-4 weeks increased taurine concentration of the extensor digitorum longus (EDL, fast-twitch) muscle of the rat. The uptake of [3H]-taurine into the EDL and tibialis anterior (TA, fast-twitch) muscle was also increased by the stimulation. Concentration and uptake of taurine in the soleus muscle (SL, slow-twitch) did not change by chronic 10 Hz stimulation. Taurine concentration in the SL muscle was significantly reduced by chronic 100 Hz stimulation. This study shows that chronic nerve stimulation increases the uptake of taurine in the fast-twitch muscles, but not in the slow-twitch muscle.View full abstractDownload PDF (274K) -
Chia Cheng CHANG, Yoshio GOSHIMA, Yoshimi MISU1986 Volume 42 Issue 3 Pages 447-449
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSUsing high performance liquid chromatography with an electrochemical detector, we examined antagonistic effects of l- and d-acebutolol and atenolol against isoproterenol-induced facilitation of impulse-evoked release of endogenous norepinephrine and dopamine in rat hypothalamic slices. Isoproterenol (10 nM) increased the release of the both catecholamines, and this facilitation was similarly antagonized by 100 nM l-acebutolol and 100 nM atenolol, but was not antagonized by 100 nM d-acebutolol. In conclusion, there exist stereoselective presynaptic β1-adrenoceptors on noradrenergic and dopaminergic neurons in the rat hypothalamus.View full abstractDownload PDF (183K) -
Junzo KAMEI, Tomokazu HOSOKAWA, Saizo YANAURA, Takehiko HUKUHARA1986 Volume 42 Issue 3 Pages 450-452
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSThe present study had two basic purposes: 1) to observe the effect of methysergide on the cough reflex and 2) to investigate the effect of methysergide on the antitussive effect of dextromethorphan. Male and female cats were anesthetized with pentobarbital-Na. Respiration and cough reflex were measured using a pneumotachograph via a cannula inserted into the trachea. The cough reflex was elicited by electrical stimuli to the superior laryngeal nerve. Methysergide (3 mg) injected into the vertebral artery increased the number of coughs and respiratory frequency. Dextromethorphan in a dose of 3 mg inhibited the cough reflex. Methysergide (1 and 3 mg) reduced the antitussive effect of dextromethorphan in a dose-dependent manner, but did not inhibit the excitatory effect on respiratory frequency. These findings might indicate that the central serotonergic system has an inhibitory role on the cough reflex and may be related to the antitussive mechanisms of dextromethorphan.View full abstractDownload PDF (167K) -
Yoshiki IWABUCHI, Chihiro AOKI, Taizo MASUHARA1986 Volume 42 Issue 3 Pages 453-456
Published: 1986
Released on J-STAGE: September 15, 2006
JOURNAL FREE ACCESSThe action of substance P on glycoprotein secretion from acinar cells of the rat submandibular gland was described in this report. Salivation elicited by i.v. injection of 0.5 to 20 μμg/kg of substance P was increased dose-dependently, and its flow rate was highest at the first 1 min. Major glycoprotein species secreted into saliva by substance P-stimulus were shown to be electrophoretically identical with those found in acini, but not granular convoluted tubules. These results support the view that substance P acts on acinar cells of the submandibular gland and stimulates secretion of saliva from the cells.View full abstractDownload PDF (187K)
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