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Volume 94 (1989)
- Issue 6 Pages 329-
- Issue 5 Pages 257-
- Issue 4 Pages 207-
- Issue 3 Pages 159-
- Issue 2 Pages 91-
- Issue 1 Pages 1-
Volume 94, Issue 2
Displaying 1-9 of 9 articles from this issue
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Tomio SEGAWA1989 Volume 94 Issue 2 Pages 91-102
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe existence of two different functional receptors for 5-hydroxytryptamine (5-HT) was first proposed by Gaddum and Picarelli. Aided by the development of radioligand binding techniques, the heterogeneity of 5-HT receptors has become more apparent in the past ten years. There are three main types of 5-HT receptors: 5-HT1, 5-HT2 and 5-HT3. Moreover, 5-HT, is heterogenous and can be divided into 5-HT1A, 5-HT1B, 5-HT1C and 5-HT1D subtypes. 5-HT1B is probably related to the 5-HT autoreceptor controlling 5-HT release. Multiple 5-HT receptors are differentially distributed throughout the brain, and the agonist-receptor interaction is altered by physical parameters and chemicals, suggesting that the receptors may be physiologically relevant. Three 5-HT receptor subtypes, 5-HT1A, 5-HTIC and 5-HT2, have been cloned. All three receptors contain approximately 450 amino acids arrayed as seven transmembrane domains. 5-HT1 and 5-HT1A are coupled to adenylate cyclase positively and negatively, respectively, while 5-HTIC and 5-HT2 are coupled positively to phospholipase C. 5-HT1A is also coupled to the opening of K+ channels in hippocampal pyramidal cells. A number of 5-HT-induced physiological responses have been shown to correlate with the 5-HT receptor subtypes. Based on a number of pharmacological studies, it seems likely that the mode of action of certain psychotropic drugs is closely related to the activity of central 5-HT receptors.View full abstractDownload PDF (9301K) -
Taizo KITA, Toshikatsu NAKASHIMA1989 Volume 94 Issue 2 Pages 103-112
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSRepeated administration of nicotine induces tolerance and/or reverse tolerance of spontaneous motor activity in rodents. These effects of nicotine on the spontaneous motor activity have been shown to be influenced by drug factors (e.g., doses, elapsed time after injection, period of treatment), circadian rhythm, age, sex, strain and species of animals. Although nicotinic acetylcholine receptors in the brain participate in the effects of nicotine, the development of tolerance and reverse tolerance is not sufficiently explained by changes in the receptor sites. Recently, neurochemical and behavioral studies have shown the possibility that reverse tolerance of nicotine on the spontaneous motor activity is probably concerned with the dopaminergic system through nicotinic acetylcholine receptors in the striatum or mesolimbic dopaminergic system of the rat brain. The present knowledge about the tolerance and reverse tolerance of nicotine on spontaneous motor activity is discussed in this review.View full abstractDownload PDF (6976K) -
Yoshiyuki HIYAMA, Kiyoshi KURIYAMA, Kiyonoshin ICHIKAWA, Toshiaki OKUD ...1989 Volume 94 Issue 2 Pages 113-118
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSA marked tuberculin response as well as carrageenin edema were induced in rat hind paw to compare the effects of antiinflammatory agents on these responses. Non-steroidal antiinflammatory agents such as diclofenac and piroxicam were very weak inhibitors of the paw tuberculin response. These agents showed only a slight inhibitory effect on tuberculin response even at doses that were four to five times larger than the 50% effective doses for inhibiting carrageenin edema. On the other hand, steroidal antiinflammatory agents, dexamethasone and prednisolone, showed potent inhibitory effects on the paw tuberculin response at the 50% effective doses for inhibiting carageenin edema. The above findings clearly revealed the difference in characters between non-steroids and steroids by comparing their effects on tuberculin response and carrageenin edema. The different properties of two classes of antiinflammatory drugs may be of significance in evaluating the effect of antiinflammatory agents on delayed-type hypersensitivity.View full abstractDownload PDF (3999K) -
Wasako ODA-KURIO, Reiko FUKUNAGA, Chiyoko INAGAKI1989 Volume 94 Issue 2 Pages 119-122
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe membrane potential of rat brain synaptosomes was depolarized by ethanol at concentrations of over 0.8 ?? 1.6%. This ethanol-induced depolarization was augmented by 4-aminopyridine (4-AP) or the gluconate--medium, but not affected by tetrodotoxin, choline-Cl, NH4Cl, picrotoxin, ethacrynic acid, furosemide or SCN--medium. The ethanolinduced depolarization was augmented by 4-AP in Cl- or gluconate--medium, but not in SCN--medium. These findings suggest that ethanol depolarizes the synaptosomal membrane potential through potassium and anion-related mechanisms, probably through potassium channels.View full abstractDownload PDF (2842K) -
Miwa MISAWA, Yutaka HASEGAWA1989 Volume 94 Issue 2 Pages 123-128
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSBromhexine has been widely used as a mucolytic expectorant. Clinically, bromhexine is sometimes administered by inhalation. However, the effect of bromhexine by inhalation on bronchial musculature has not been documented. In the present study, the effect of inhaled bromhexine on bronchomotor tone in rats and guinea pigs was investigated. The bronchomotor tone was measured by a modified Konzett-Rössler method, and ventilation overflow (VO) was continuously recorded as an index of airway resistance. In rats, inhalation of bromhexine (0.1% and 0.2%, pH 5.3) caused no change in VO. At 0.2%, bromhexine slightly decreased systemic blood pressure (BP). In guinea pigs, bromhexine had no significant effect on VO at 0.2%, and it produced a significant but very slight increase at 0.1%. BP was slightly decreased by inhalation of bromhexine (0.1% and 0.2%, pH 5.3). N-Acetyl-L-cysteine, a cysteine-mucolytic (20%, pH 6.8), had no effect on VO and BP in either species. Inhalation of 0.1% bromhexine solution at pH 2.5, which was dissolved in tartaric acid solution, significantly increased VO, because of its acidity. From the above results, it is suggested that when the pH of the solution is considered, bromhexine has no or almost negligible effect on airway smooth muscles, and it may be useful as an effective mucolytic.View full abstractDownload PDF (4862K) -
Yukisumi IIZUKA, Eiichi SAKURAI, Noboru HIKICHI, Hiroshi NIWA1989 Volume 94 Issue 2 Pages 129-135
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe activities of lysosomal maltase in the serum, urine and kidney were determined in rats with diabetes induced by streptozotocin (STZ, 75 mg/kg, i.p.) and compared with the changes in N-acetyl-β-D-glucosaminidase (NAG) activity. Moreover, effects of insulin on maltase and NAG activities of the serum, urine and kidney in diabetic rats were studied. The following results were obtained: 1) The serum maltase activity within 24 hr after administration of STZ was influenced by insulin secretion. 2) Significant increases in blood urea nitrogen (BUN) levels were observed from the 3rd week after a single administration of STZ. The serum insulin level significantly decreased at 3 weeks after treatment of STZ. In this time, maltase activity in the serum rapidly increased, while the enzyme activity in the kidney decreased considerably. On the other hand, the changes in NAG activities in the serum, urine and kidney after administering STZ were almost similar to those in maltase activities. 3) There were positive relationships between maltase and NAG activities in the serum and urine in diabetic rats, respectively. 4) When lente insulin (2U) was subcutaneously injected once daily for 20 days from 24 hr after administration of STZ, NAG activities in the serum and kidney approached to the control levels. However, maltase activities in the group treated with insulin were significantly higher in the serum and kidney than those in the control group.View full abstractDownload PDF (4890K) -
Sadao NAKAYAMA, Mayumi YAMAUCHI, Katsuji OGUCHI1989 Volume 94 Issue 2 Pages 137-144
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe effect of Laennec (human placenta hydrolysate) on CCl4-induced acute or chronic liver injury in rats was examined. In the acute liver injury induced by CCl4, 0.5 ml/kg for 4 days, intravenous injection of Laennec increased total protein and decreased nonesterified fatty acid in the liver. Subcutaneous injection of Laennec inhibited the decrease of liver phospholipid by CCl4 administration. Both intravenous and subcutaneous injections of Laennec inhibited the increases of serum transaminase (GOT, GPT) levels caused by CCl4. Furthermore, intravenous Laennec inhibited the increase of serum alkaline phosphatase level. Pathological examinations of the liver indicated that both intravenous and subcutaneous injections of Laennec inhibited the loss of cytoplasma and nuclei, vacuolation, swelling and necrosis in the centrizonal hepatocytes caused by CCl4. Intravenous and subcutaneous injection of Laennec also inhibited the increases of GOT and GPT levels in rats with chronic liver injury caused by CCl4, 0.5 ml/kg for 7 weeks. Both intravenous and subcutaneous injections of Laennec minimized the pathological changes of the liver by CCl4 such as vacuolation, necrosis and swelling of nuclei, but did not inhibit the formation of pseudolobules. Thus, no therapeutic difference was noted between intravenous and subcutaneous injections of Laennec.View full abstractDownload PDF (7557K) -
Akihiro HARUNO, Yasundo YAMASAKI, Kazuhisa MIYOSHI, Hidekazu MIYAKE, K ...1989 Volume 94 Issue 2 Pages 145-150
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSThe effects of P-4 and its active metabolites in human blood and urine and the effects of 1-methyl-4-piperidyl diphenylpropoxyacetate N-oxide CP-4(N→O)), 1-methyl-4-piperidyl benzilate N-oxide (DPr-P-4(N→O)) and 1-methyl-4-piperidyl benzilate (DPr-P-4) on isolated guinea pig urinary bladder were investigated. At doses of 10-6 or 10-5 M, P-4 shifted the dose-response curve for acetylcholine (ACh) to the right, and at a dose of 10-5 M, it also inhibited the maximum response of ACh. At doses of 10-5 M or more, P-4(N→O) inhibited the maximum response of ACh. DPr-P-4(N→O) or DPr-P-4 shifted the dose-response curve for ACh to the right at doses of 10-6 ?? 10-4 M or at doses of 10-7 ?? 10-5 M. P-4 at doses of 10-6 M or more inhibited the KCl (100 mM)-induced contraction in a dose-dependent manner, and its potency was quite equal to that of terodiline. The inhibitory effect of P-4(N→O), DPr-P-4(N→O) and DPr-P-4 in the KCl (100 mM)-induced contraction were weaker than that of P-4. P-4 and P-4(N→O) had a dose-dependent inhibitory effect on K+-induced 45Ca influx in isolated guinea-pig urinary bladder. These results indicated that P-4 had mainly a direct action on the smooth muscle of isolated guinea pig urinary bladder, and P-4(N→O) had the same effect as those of P-4 and DPr-P-4(N→O) or DPr-P-4 had an anticholinergic effect.View full abstractDownload PDF (4242K) -
Shigeru KANEKO, Kenji KITAZATO, Yasuhide YAMAZAKI, Hiromasa OKADA1989 Volume 94 Issue 2 Pages 151-157
Published: 1989
Released on J-STAGE: February 20, 2007
JOURNAL FREE ACCESSPropiverine hydrochloride (P-4) is a new derivative of benzilic acid. The effect of P-4 on the vesico-detrusor reflex (corresponding to the first reflex of Barrington) in anesthetized or decerebrated dogs was studied to elucidate the mode of action of the drug. When bladder contraction was induced by electrical stimulation of the distal ending of the pelvic nerve under the bilateral pelvic nerve and hypogastric nerve transection, P-4 (2, 5 and 10 mg/kg, i.v.) significantly inhibited the contraction. A similar effect was also observed following intravenous administration of flavoxate (10 and 20 mg/kg), verapamil (1 mg/kg) or propantheline (2 mg/kg), while thiopental (4 mg/kg, i.v.) had no significant effect. When the bladder was filled under the bilateral pelvic nerve and hypogastric nerve transection, an increase of afferent impulses from the distal ending of a pelvic vesical branch was observed. P-4 (10 mg/kg, i.v.) had no effect on the afferent impulses. When the central endings of the pelvic vesical branches were electrically stimulated, reflex discharges were noted from a pelvic vesical branch on the contralateral side. Thiopental (2 and 4 mg/kg, i.v.) markedly decreased the reflex discharge, whereas P-4 (10 mg/kg, i.v.) caused no such inhibition. These findings suggest that the inhibition of the vesico-detrusor reflex by P-4 may result from its inhibitory action on the efferent terminal of the pelvic nerve.View full abstractDownload PDF (5090K)
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