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Biomedical subjects

M Misawa

Publications and source records attributed to M Misawa.

At least 181 records · Page 10Linked to original sources
PubMed1993

The antitussive effect of cromakalim in rats is not associated with adenosine triphosphate sensitive K+ channels.

The effects of cromakalim, a K+ channel opener, on the capsaicin-induced cough reflex in rats were studied. I.P. administration of cromakalim in doses of 0.1 to 1.0 mg/kg decreased the number of induced coughs in a dose- dependent manner. Neither glibenclamide, an adenosine triphosphate-sensitive K+ channel blocker, nor tetraethylammonium, a blocker of other types of K+ channels, affected the antitussive effect of cromakalim. However, the antitussive effect of cromakalim was antagonized by methysergide, a 5-HT antagonist. Although Bay K 8644, a dihydropyridine Ca2+ channel activator, had a marked cough-depressant effect, it had no effect on the antitussive effect of cromakalim. These results suggest that the antitussive effect of cromakalim is primarily mediated by activation of the serotonergic system through the inhibition of voltage-dependent Ca2+ channels, and not through the activation of K+ channels.

Adenosine Triphosphate↗
PubMed1993

Effects of diabetes on the antinociceptive effects of intrathecally administered endothelin-1.

Intrathecal administration of endothelin-1 (ET-1) produced a dose-dependent increase in tail-pinch latency, i.e., antinociception, in both diabetic and non-diabetic mice. The dose ranges which produced a significant antinociception in diabetic mice (0.0001 to 0.0003 nmol) were lower than those in non-diabetic mice (0.001 to 0.003 nmol). Furthermore, the antinociceptive effect of ET-1 in diabetic mice was decreased when the doses of ET-1 were increased. Indeed, when ET-1 in a dose of 0.003 nmol, which produced significant antinociception in non-diabetic mice, it had no antinociceptive effect in diabetic mice. These results suggest that the mechanism which underlies the antinociceptive effects of ET-1 is up-regulated in diabetic mice, as compared with that in non-diabetic mice.

Animals↗
PubMed1993

An airway hyperresponsiveness model in rat allergic asthma.

We attempted to obtain a new airway hyperresponsiveness model using DNP-Ascaris extract (DNP-Asc)-induced rat allergic asthma. Male Wistar rats were actively sensitized with DNP-Asc, and challenged in a non-anesthetized state by inhalation of the antigen for 10 min in a chamber. One, 6 and 24 hr after DNP-Asc challenge, the responsiveness of the airway smooth muscles to inhaled acetylcholine (ACh) was determined using a modified Konzett-Rössler method under anesthesia. Twenty four hr after the challenge, a significant and marked airway hyperresponsiveness was seen. The increase in airway responsiveness was significantly inhibited by pretreatments with a leukotriene antagonist, ONO-1078, and a thromboxane synthetase inhibitor, ozagrel, and tended to be inhibited by a PAF antagonist, CV-3988. The hyperresponsiveness induced by DNP-Asc challenge was accompanied by airway inflammation determined by dye exudation. From the above results, it is indicated that a model of airway hyperresponsiveness was established in rats with allergic asthma, and that the chemical mediators involved in the response might be leukotrienes, thromboxane A2 and PAF.

Acetylcholine↗
PubMed1992

Involvement of haloperidol-sensitive sigma-sites in antitussive effects.

The effects of selective sigma-ligands on the capsaicin-induced cough reflex in rats were studied. Intraperitoneal injection of (+)-N-allylnormetazocine ((+)-SKF-10,047) and N,N'-di(ortho-tolyl)guanidine (DTG) in doses that ranged from 0.3 to 3.0 mg/kg decreased the number of coughs dose dependently. The antitussive effects of these sigma-ligands were significantly attenuated by pretreatment with haloperidol. Pretreatment with haloperidol also markedly reduced the antitussive effects of (+/-)-pentazocine and dextromethorphan. These results suggest that haloperidol-sensitive sigma-sites may be involved in the regulation of coughs.

Animals↗
PubMed1992

Role of central ATP-sensitive potassium channels in the analgesic effect and spinal noradrenaline turnover-enhancing effect of intracerebroventricularly injected morphine in mice.

Glibenclamide is one of the most potent sulfonylurea-derived antidiabetic drugs which block the adenosine triphosphate-sensitive potassium (KATP) channels. In the present study, we found that none of morphine, U-50,488H (a selective kappa agonist) and baclofen (a selective GABAB agonist) added to the incubation medium at concentrations up to 10(-4) M had appreciable effect on the specific binding of [cyclohexyl-2,3-3H(N)]glibenclamide ([3H]glibenclamide) to the isolated mouse brain microsomes. The analgesic activity induced by intracerebroventricular injection (i.c.v.) of morphine but not U-50,488H was antagonized by pretreatment with either i.c.v. glibenclamide or beta-funaltrexamine (beta-FNA; a selective mu antagonist) in mice. Furthermore, the increasing effect of i.c.v. morphine on the spinal noradrenaline (NA) turnover was greatly antagonized by i.c.v. pretreatment with either beta-FNA or glibenclamide. From these results, we demonstrated that KATP channels play an important role as indirect modulators of the supraspinal analgesia induced by mu agonist but not kappa agonist in mice, and the activation of descending noradrenergic system induced by i.c.v. morphine appears to be suppressed by the blockade of KATP channels.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1992

Effects of nor-binaltorphimine on the development of analgesic tolerance to and physical dependence on morphine.

The effects of a highly selective kappa antagonist, nor-binaltorphimine (nor-BNI), on the development of tolerance to morphine analgesia and physical dependence on morphine were examined. Pretreatment with nor-BNI (5 mg/kg s.c.) 2 h prior to injection of morphine or a selective kappa agonist, U-50,488H, significantly antagonized the analgesic effect of U-50,488H, but not morphine analgesia in mice. The development of tolerance to morphine analgesia was significantly potentiated by pretreatment of mice with nor-BNI 2 h prior to morphine treatment during chronic morphine treatment for 5 days. Additionally, the pretreatment with nor-BNI during chronic treatment with the high dose of morphine for 5 days significantly potentiated the naloxone-induced body weight loss in morphine-dependent mice and rats. These findings suggest that inactivation of the kappa opioid system may potentiate the development of tolerance to morphine analgesia in mice and may aggravate the naloxone-precipitated body weight loss in morphine-dependent mice and rats.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1992

Role of central ATP-sensitive potassium channels in the hyperthermic effect of morphine in mice.

Morphine (10 mg/kg, SC) in combination with ICV vehicle induced a significant hyperthermic effect at 120 min (peak time) after injection compared to ICV vehicle plus SC saline (control group). Glibenclamide (50 micrograms, ICV), a selective adenosine triphosphate-sensitive potassium (KATP) channel blocker, in combination with SC saline hardly affected the rectal temperature compared to the control group. ICV glibenclamide antagonized the hyperthermia induced by SC morphine in a dose-dependent manner. From these results, we demonstrated that KATP channels play an important role as modulators of the hyperthermic effect of mu agonists.

Adenosine Triphosphate↗
PubMed1992

The role of mu1 receptor in physical dependence on morphine using the mu receptor deficient CXBK mouse.

It is known that the CXBK inbred strain of mouse is deficient in mu1 opioid receptors, whereas the strain has a delta opioid receptor population that is less consistently altered. In the present study, we compared physical dependence on morphine between CXBK and C57BL/6 mice. Both strains of mice were treated with morphine-admixed food for 5 days. During the treatment, the two strains of mice showed no signs of toxicity. There was no significant difference in morphine intake during the treatment between CXBK and C57BL/6 mice. After the treatment, the withdrawal was precipitated by injecting naloxone (0.01-30 mg/kg, s.c.). CXBK mice showed weight loss, diarrhea and ptosis, but not jumping and body shakes after low dose of naloxone. Whereas, C57BL/6 mice showed weight loss, diarrhea, ptosis, body shakes and jumping. These results suggest that naloxone-precipitated weight loss, diarrhea and ptosis may be mediated by mu2 and/or delta opioid receptor, while naloxone-precipitated jumping and body shakes may be mediated by mu1 opioid receptors.

Animals↗
PubMed1992

Genetic differences in the development of physical dependence upon diazepam in Lewis and Fischer 344 inbred rat strains.

The purpose of the present study was to investigate physical dependence upon diazepam systematically in two inbred strains of rats, Lewis (LEW) and Fischer 344 (F344). Rats were chronically fed food containing diazepam on an escalating drug dosage schedule, from 1 and 2 to 12 mg/g of food, over a period of 30 days. During treatment, the growth curve in LEW and F344 rats was suppressed compared with the respective controls. Motor incoordination was evaluated by a rotarod performance test. The ranking of the motor incoordination during the final concentration of diazepam was as follows: F344 greater than LEW. After substitution of normal food for the diazepam-admixed food, various signs of diazepam withdrawal occurred 16-120 h later. These signs included vocalization, irritability, muscle rigidity, ear-twitching, Straub's tail, piloerection, fascicular twitch, tremor, convulsion, and death. The incidences of vocalization, ear-twitching, piloerection, and tremor in F344 were significantly higher than those in LEW rats. Furthermore, two of six F344 rats showed spontaneous convulsions and one rat died of convulsions. Overall withdrawal scores were significantly greater in F344 (16.0) than in LEW (6.3) rats. These results suggest that diazepam withdrawal severity is strongly influenced by genetic factors, and F344 rats are highly susceptible to dependence upon benzodiazepines.

Animals↗
PubMed1992

Susceptibility to, tolerance to, and physical dependence on ethanol and barbital in two inbred strains of rats.

1. Ethanol-induced sleep time was significantly longer in F344 than LEW rats. However, there is no difference in barbital-induced sleep time between F344 and LEW. 2. Development of tolerance to ethanol-induced motor impairment was slightly faster in F344 than in LEW rats. While, LEW rats more easily developed tolerance to the impairment by barbital in comparison with F344 rats. 3. F344 and LEW rats were chronically treated with liquid diet containing ethanol or with barbital-admixed food. After the termination of ethanol and barbital treatments, various withdrawal signs occurred in F344 rats, including tremor and convulsions, whereas LEW rats showed no convulsions. Withdrawal scores of ethanol and barbital were significantly higher in F344 than in LEW rats. 4. These results suggest that strain differences in physical dependence on ethanol and barbital may be mainly influenced by the susceptibility to ethanol and the development of tolerance to barbital, respectively.

Animals↗
PubMed1992

Inhibitory reflex during bronchoconstrictions induced by histamine and Ascaris suum antigen.

We investigated the involvements of sympathetic and nonadrenergic nervous systems in the inhibitory reflex following bronchoconstriction in dogs. Inhalations of a 0.00125% solution of histamine and Ascaris suum antigen (3 mg protein) to the bronchial side induced reflex tracheal constriction following bronchoconstriction. An intra-arterial infusion of 5 micrograms/min of atropine to the tracheal site changed the reflex tracheal constrictions by histamine and antigen inhalations into tracheal dilatations. The reflex tracheal dilatations were abolished by the combination of intra-arterial propranolol (100 micrograms) and transections of both the bilateral superior laryngeal nerves and the spinal cord at the C1 level. The reflex tracheal constrictions induced by histamine and antigen inhalations were increased with 100 micrograms propranolol. Furthermore, the reflex tracheal constrictions were enhanced by the combination of 100 micrograms propranolol and transection of the spinal cord. These findings indicate that during the constriction of the bronchial smooth muscle, not only a reflex tracheal constriction mechanism but also one of reflex dilatation operates and that the latter reflex response may be mainly mediated by the sympathetic nerves, with partial involvement of the nonadrenergic nerves. This inhibitory reflex may attenuate asthmatic bronchoconstriction.

Administration, Inhalation↗
PubMed1992

The role of mu- and kappa-opioid receptors in cocaine-induced conditioned place preference.

Effects of buprenorphine, U-50,488H, naltrexone and lithium chloride on cocaine conditioned place preference were examined. Buprenorphine, a mixed opioid agonist-antagonist, blocked the cocaine-induced place preference. Furthermore, the kappa-receptor agonist U-50,488H and the mu-receptor antagonist naltrexone both antagonized the cocaine preference. U-50,488H or naltrexone alone induced a place aversion in a dose-dependent manner. However, the cocaine-induced conditioned place preference was not blocked by lithium chloride, although the latter induced a conditioned place aversion, indicating that the antagonism of cocaine-induced place preference by U-50,488H or naltrexone does not result from a functional antagonism. These results suggest that mu- and kappa-opioid receptors may be involved in cocaine-induced conditioned place preference.

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗
PubMed1992

[The analects of Hajime Hoshi (No. 3) - philosophy of Hoshi].

Hajime Hoshi was the founder of Hoshi Pharmaceutical Company and Hoshi University. He made one of the biggest pharmaceutical companies in Japan in the early 20th century, and furthermore was a journalist, member of the Diet, educator, and also a writer. With such a checkered career, he had an attractive and invincible philosophy. As well as his most import philosophy "kindness first" described in the previous paper, "cooperation first" also had weight in his thought. In the Creed of the Hoshi Pharmaceutical Company, he said "self-reliance should go hand-in-hand with cooperation. Cooperation is an essential requisite in all successful enterprises." "Cooperation is an order of the god, and leads directly to progress." "Cooperation is construction, but noncooperation is destruction." Besides the thought "cooperation first," a part of his profound aphorism is described below. "Patience produces everything and conquers everything." "Success is proportioned to the degree of patience." "Success or failure is determined not at the end, but at the start of an enterprise. A well-conceived plan is the mother of success." "Train your mind. Man's brains become the more fertile and keen, the more they are used." "The is no limit to improvement and invention. We should never relax our endeavor to improve and invent." "Smile! Smile! Do your work with a smile on your face. Conquer difficulty and discontent with smiles." "Yesterday's impossibility is today's possibility. Today's impossibility is tomorrow's possibility."

Commerce↗
PubMed1992

[Effects of dietary proteins on analgesic activity of tolerance and physical dependence on morphine in rats].

Effects of dietary proteins such as casein and egg albumin on analgesic activity of, tolerance to and physical dependence on morphine in rats were examined. There was no difference in analgesic activity after acute administration of morphine 10 mg/kg, s.c. between rats treated with casein food or egg albumin food and normal food for 5 or 21 days. The development of tolerance to morphine analgesia in rats treated with albumin food but not with casein food was suppressed during daily morphine 10 mg/kg, s.c. on 5 consecutive days. Rats were treated with casein or albumin food mixed with morphine (0.5 mg/g of food) for 5 days. Morphine intake in rats treated with albumin food was significantly decreased as compared to that with morphine admixed casein or normal food. Body weight loss by naloxone in morphine-dependent rats was significantly less in both casein food and albumin food groups than in the normal food group. These results suggest that chronic dietary treatment with albumin may produce a partial inhibition of development of tolerance to morphine analgesia and that with casein may attenuate morphine withdrawal manifestation in rats.

Analgesics, Opioid↗
PubMed1992

5-HT3 receptor antagonists block cocaine- and methamphetamine-induced place preference.

The effects of 5-HT3 receptor antagonists, MDL72222 and ICS205-930, on cocaine- and methamphetamine-induced place preference were examined. Cocaine (0.5-4.0 mg/kg, ip) and methamphetamine (0.25-2.0 mg/kg, ip) induced a dose-dependent place preference. The cocaine (4 mg/kg)-induced place preference was blocked by both MDL72222 and ICS205-930 (0.1 mg/kg, ip). On the other hand, the dose (0.1 mg/kg) of 5-HT3 antagonists did not block the methamphetamine (2 mg/kg)-induced place preference, although a higher dose (1.0 mg/kg) of 5-HT3 receptor antagonists did block it. The difference in sensitivity may reflect a difference in attack point in dopaminergic system of these two psychostimulants. Our findings suggest that the rewarding effects of cocaine and methamphetamine may be indirectly regulated by 5-HT3 receptor; cocaine being more sensitive to 5-HT3 receptor antagonists than methamphetamine.

Animals↗
PubMed1992

Establishment of the ethanol-induced place preference in rats.

Ethanol failed to induce a place preference in both 15 and 50 min conditioning schedules in free-feeding and in food deprived rats. Acetaldehyde, the primary metabolic product of ethanol, induced a weak place aversion, dose-dependently. Ethanol combined with pyrazole (an alcohol dehydrogenase inhibitor) significantly induced a place preference in rats (ethanol; 300 mg/kg, i.p., pyrazole; 100 mg/kg, i.p.) in a 50 min conditioning schedule. The ethanol (300 mg/kg) combined with pyrazole (100 mg/kg)-induced place preference was antagonized or reduced by 5-HT3 antagonists (MDL72222, ICS205-930). These results suggest that a blockade of ethanol metabolism is very important for development of the ethanol-induced place preference in rats, and that the ethanol-induced place preference may be mediated by the mesolimbic dopamine system through 5-HT3 receptors.

Animals↗
PubMed1992

Effects of calcium antagonists on the cocaine- and methamphetamine-induced conditioned place preference.

The effects of calcium antagonists (nifedipine, flunaridine and diltiazem) on the cocaine- and methamphetamine-induced place preference were examined. Calcium antagonists alone induced neither place preference nor place aversion. Nifedipine markedly antagonized and flunarizine and diltiazem reduced the cocaine-induced place preference. The methamphetamine-induced place preference was reduced by nifedipine and diltiazem, but not by flunarizine. These results suggest the possibility that the cocaine-induced place preference is strongly influenced by dihydropyridine sensitive calcium channels, whereas the methamphetamine-induced place preference is not.

Animals↗