PubMed Health⌕ Search

Biomedical subjects

C Hara

Publications and source records attributed to C Hara.

At least 55 records · Page 3Linked to original sources
PubMed1986

Biphasic effects of MIF-1 and Tyr-MIF-1 on apomorphine-induced stereotypy in rats.

The effects of several doses of MIF-1 and Tyr-MIF-1 (0.2, 0.5, 1.0 and 5.0 mg/kg, SC) on the stereotypic behavior induced by various doses (0.08, 0.2, 0.5, 1.0 and 2.0 mg/kg, SC) of apomorphine (APO) were tested in rats. MIF-1 increased the stereotypic behavior induced by 0.5 and 1.0 mg/kg of APO, but decreased the stereotypic behavior induced by 2.0 mg/kg of APO. Tyr-MIF-1 showed a biphasic effect similar to that exerted by MIF-1. The results suggest that the type of response to MIF-1 and Tyr-MIF-1 after APO is influenced by the activity of central dopaminergic neurons.

Animals↗
PubMed1986

Acute administration of MIF-1 or Tyr-MIF-1 inhibits haloperidol-induced catalepsy in rats.

The effects of MIF-1 (Pro-Leu-Gly-NH2) and Tyr-MIF-1 (Tyr-Pro-Leu-Gly-NH2) on haloperidol-induced catalepsy were studied in order to examine the influences of both peptides on central dopaminergic function. In the first experiment, several variables were tested. It was found that the optimal effect was achieved with a dose of 1.0 mg/kg haloperidol injected SC an hour before testing for catalepsy and 1.0 mg/kg MIF-1 injected SC 30 min before testing. In the second experiment, Tyr-MIF-1 as well as MIF-1 were injected as single injections at four doses. Catalepsy was inhibited in an inverted U-shape dose-response relationship with the maximal effect of each peptide occurring at 1.0 mg/kg. The results indicate that when careful attention is given to dose, both MIF-1 and Tyr-MIF-1 can activate dopaminergic neuronal activity after acute administration.

Animals↗
PubMed1986

Potentiation of haloperidol-induced catalepsy by beta-adrenoceptor antagonists in mice.

Several clinical papers have reported that beta-adrenoceptor antagonists were useful in the management of schizophrenia and tardive dyskinesia. The present study examined effects of beta-antagonists on haloperidol (HAL)-induced catalepsy using mice in order to study the relationship between beta-antagonists and central dopaminergic functions. Catalepsy was tested by the standard bar test 30 min after intraperitoneal treatment of HAL. Beta-antagonists were administered subcutaneously just after HAL-treatment. Propranolol, alprenolol, oxprenolol and pindolol increased the incidence of catalepsy compared to HAL alone. Atenolol, not penetrating into the brain, and the sedative and hypnotic drug chlordiazepoxide did not potentiate it. These results suggest that the potentiation of HAL-catalepsy by beta-antagonists is based on their central action. Therefore, a central beta-receptor appears to be implicated in the regulation of the central dopaminergic functions.

Adrenergic beta-Antagonists↗
PubMed1984

Anti-muricide mechanisms of chlorpromazine and imipramine in OB rats: adrenoceptors and hypothalamic functions.

Chlorpromazine (CPZ) microinjected into the posterior part of the lateral hypothalamus (p-LH) and the lateral preoptic area (1-POA) of OB rats shows anti-muricide and cataleptogenic effects as well as a drowsy pattern in cortical EEG, while imipramine (IMP) injected into p-LH shows anti-muricide and cataleptogenic effects without change of cortical EEG. The present study examined the effects of drugs injected into p-LH and 1-POA on muricide, catalepsy and cortical and limbic EEG. CPZ (20, 50 micrograms) suppressed muricide and induced catalepsy and an EEG drowsy pattern in the two regions. The effects of CPZ in p-LH were similar to those of propranolol (PRO). In 1-POA, the anti-muricide effect of CPZ was similar to that of phenoxybenzamine, whereas the cataleptogenic and EEG effects were similar to those of PRO. IMP (10, 20 micrograms) in p-LH showed anti-muricide and cataleptogenic effects and induced a slight drowsy pattern in limbic EEG. The effects were similar to those of atropine. Lidocaine did not show any effects in the two regions. The cataleptogenic effects of CPZ and IMP did not appear related with the anti-muricide effects. The results suggest that the anti-muricide effect of CPZ in the hypothalamus depends on its adrenoceptor blockage, while that of IMP relates to its anticholinergic effect. In addition, beta-receptors in the hypothalamus appear related to the arousal system and dopaminergic functions.

Aggression↗
PubMed1983

Influence of maturation on ulcer-development and immunodeficiency induced by activity-stress in rats.

Young adult rats housed in the activity-wheel cages and fed only 1 hr daily, have ulcers in the glandular stomach and reveal immunodeficiency. The present study was attempted to investigate how to separate the ulceration and immunodeficiency in order to utilize the activity-stress (A-S) model as an animal model of the human stress ulcer. Six and 10 weeks old rats were used as subjects in this study. They were stressed for 3, 5, or 7 days. In the younger rats, the longer stress exposure caused to deteriorate more both the ulcer and immunodeficiency. The ulceration was found in all of the three stress periods, while the immunodeficiency was recognized in the 5- and 7-day stressed rats. In the elder rats, the ulceration was found in the 5- and 7-day stressed rats, whereas the immunodeficiency was seen only in the 7-day stressed rats. In the free-feeding control rats, relative weights of the thymus and spleen in the elder rats were smaller than those of the younger rats. In the adrenal weight, there was no difference between two age rats. The thymus and spleen of rats exposed to the stress revealed atrophy in both ages. These results suggest that immature rats are more susceptible for the stress than young mature rats, and application of mature rats to the A-S experiment appears to be available in the case of utilizing A-S rats as the stress ulcer model.

Adrenal Glands↗
PubMed1983

Effects of psychotropic drugs microinjected into the hypothalamus on muricide, catalepsy and cortical EEG in OB rats.

In order to elucidate the mechanism of anti-muricide action of psychotropic drugs in the brain, the present study examined influences of these drugs microinjected into the hypothalamus on muricide. Inhibition of muricide by chlorpromazine (CPZ) was found both in the lateral preoptic area (1-POA) and the posterior part of the lateral hypothalamus (p-LH), and that by chlordiazepoxide was seen only the mammillary body. These effects were accompanied by a drowsiness of cortical EEG. Anti-muricide action of tricyclic antidepressants was found in p-LH. The effect was not accompanied by EEG drowsiness. Effects of atropine injected into the hypothalamus on muricide and cortical EEG were similar to those of the antidepressants. Norepinephrine and serotonin did not show selective muricide-suppression. Although either CPZ in 1-POA and p-LH or the antidepressants in p-LH showed cataleptogenic effect, these effects did not appear related to anti-muricide action. The relationship between the anti-muricide action of psychotropic drugs and the physiological functions of the brain was discussed in comparison with these systemic administrations.

Aggression↗
PubMed1983

Polysaccharides in fungi. XIV. Anti-inflammatory effect of the polysaccharides from the fruit bodies of several fungi.

Anti-inflammatory assays on the carrageenin-induced edema and scald-induced hyperalgesia in the hindpaw of rats were studied on polysaccharides obtained from the fruit bodies of various fungi (polysaccharide AC, BC: Tremella fuciformis;MEA, MHA, MCW-A, MCW-N: Auricularia auricula-judae; T-2-HN: Dictophora indusiata;G-A: Ganoderma japonicum). The purified polysaccharides MHA, MCW-A, G-A and T-2-HN exhibited a significant inhibitory effect on carrageenin edema. Among these polysaccharides, T-2-HN (partially O-acetylated alpha-D-mannan) also showed the marked inhibitory effect on scald hyperalgesia. We have found that T-2-HN has more potent anti-inflammatory activity than phenylbutazone in the above two inflammatory models. Since the purified polysaccharide is free from protein and lipid, it is clear that anti-inflammatory effect arises from the polysaccharide itself. The polysaccharides (T-2-HN, locust bean gun, xanthan gum) had little effect on the metabolism of arachidonic acid in canine platelets. The mechanism of the anti-inflammatory activity of the polysaccharide remains obscure.

Animals↗