It is not clear whether dopamine D(3) receptor contributes to the regional difference in dopamine antagonist-induced increase in the evoked dopamine release from the nucleus accumbens and striatum. We investigated the regional differences in augmentation of electrically evoked dopamine release induced by preferential dopamine D(2) or D(3) receptor antagonists from slices of the rat striatum and nucleus accumbens. Haloperidol, a preferential dopamine D(2) receptor antagonist, enhanced the evoked dopamine release from both the striatum and nucleus accumbens. Preferential dopamine D(3) antagonists, cis-(+)-(1S, 2R)-5-methoxy-1-methyl-2-(di-n-propylamino)tetralin HCl [(+)-UH232] and 5,6-dimethoxy-2-(di-n-propylamine)indan (U-99194A) resulted in a greater increase in the evoked dopamine released from the nucleus accumbens compared with that from the striatum. Moreover, U-99194A attenuated the quinpirole-induced reduction of evoked dopamine release from the nucleus accumbens but not from the striatum. When slices were superfused with pirenzepine, a muscarinic receptor antagonist, the increase in the evoked dopamine release by (+)-UH232 or U-99194A was reduced in the nucleus accumbens to the same level as that in the striatum. Our results indicate that the preferential D(3) receptor antagonists-induced increase in evoked dopamine release is probably mediated by the cholinergic system in the nucleus accumbens, which contains more postsynaptic dopamine D(3) receptors than the striatum.

8-Hydroxy-2-(di-n-propylamino)tetralin↗

PubMed1999

Hyperammonemia induced by administration of glucose and insulin after hepatopancreatectomy in rats.

Massive resection of both the liver and pancreas is performed as a radical procedure in some cases of advanced biliary cancer, but it has been reported that this disease is frequently complicated by hyperbilirubinemia or hepatic insufficiency postoperatively, which is a serious hindrance to performing such extended surgery (Nimura et al., 1991; Nakamura et al., 1992). To investigate the pathogenesis of hepatic dysfunction after hepatopancreatectomy, we performed 4 surgical procedures consisting of 68% hepatectomy, 90% pancreatectomy, 68% hepatectomy plus 90% pancreatectomy (hepatopancreatectomy) and sham-surgery in rats. Then, rats were continuously infused with 5% or 20% glucose solution at a constant speed (50 mL/day) for 24 hours in the fasting state, thus creating a total of 8 groups. During infusion of 20% glucose solution into rats with pancreatectomy or hepatopancreatectomy, insulin (1 U/5 g glucose) was added to the solution to adjust the blood glucose. In rats infused with 20% glucose solution with added insulin after hepatopancreatectomy, the blood glucose level did not differ, but adenosine 5'-triphosphate (ATP) and energy charge levels in the liver tissue were significantly lower, while the blood ammonia level was significantly higher than those in the other 7 groups. These results demonstrate that continuous infusion of high concentrations of glucose solution with added insulin after hepatopancreatectomy in rats reduces hepatic mitochondrial function, resulting in hyperammonemia due to reduced urea synthesis.

Alanine↗

PubMed1998

Antagonistic effects of beta-phenylethylamine on quinpirole- and (-)-sulpiride-induced changes in evoked dopamine release from rat striatal slices.

To assess the role of beta-phenylethylamine in aspects of dopamine release, we measured the level of beta-phenylethylamine in the rat striatum after killing the rats by microwave irradiation. We then investigated the effect of beta-phenylethylamine on electrically evoked dopamine release from rat striatal slices in vitro. The striatal beta-phenylethylamine level was 46.5 +/- 3.5 ng/g wet tissue, equivalent to 0.3 micromol/l. Superfusion with low concentrations of beta-phenylethylamine up to 1 micromol/l had no effect on spontaneous or electrically evoked dopamine release from striatal slices. Quinpirole reduced the evoked dopamine release from slices in a concentration-dependent manner. The quinpirole-induced reduction of evoked dopamine release was attenuated 30% by superfusion with 0.3 micromol/l beta-phenylethylamine. Moreover, the (-)-sulpiride (0.1 micromol/l)-induced increase in evoked dopamine release was also attenuated by superfusion with 0.3 micromol/l beta-phenylethylamine. These data indicate that submicromolar levels of beta-phenylethylamine could modify the dopamine autoreceptor mediated changes in evoked dopamine release from rat striatal slices.

Animals↗

PubMed1998

Dopamine autoreceptors in rat nucleus accumbens modulate prepulse inhibition of acoustic startle.

Dopamine and 3,4-dihydroxy phenylacetic acid (DOPAC) levels in discrete regions and apomorphine- or (-)-sulpiride-induced changes in electrically evoked dopamine release from nucleus accumbens slices were assessed after testing prepulse inhibition of acoustic startle (PPI) in rats. Dopamine and DOPAC levels in the nucleus accumbens, but not in the striatum, correlated well with PPI (r = -0.64 for dopamine, r = -0.48 for DOPAC). Evoked dopamine release from the nucleus accumbens did not differ between the high-PPI (more than 60%) and the low-PPI (less than 40%) group. When slices were superfused with 1 microM apomorphine, the S2/S1 ratio in rats showing high PPI was 0.77 +/- 0.02 (mean +/- SEM, 66% of control), significantly smaller than in the low-PPI group (S2/S1 ratio = 0.97 +/- 0.08, 94% of control, p < 0.05). Moreover, (-)-sulpiride-induced increase in evoked dopamine release from the nucleus accumbens in the high-PPI group was inclined to be greater than in the low-PPI group. The results suggest that PPI differences between individuals may reflect the sensitivity of release-modulating dopamine autoreceptors in the nucleus accumbens.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1998

Nitric oxide mediates cerulein-induced relaxation of canine sphincter of Oddi.

This study evaluates the hypothesis that cerulein relaxes the sphincter of Oddi (SO) via nitric oxide (NO). The spontaneous motility and the response to cerulein on the canine SO were recorded using a constant-perfusion technique. N(G)-L-arginine-methyl-ester (L-NAME) increased the spontaneous motility and dose-dependently reduced the cerulein-induced inhibitory response of the SO. After treatment with L-NAME at higher doses, cerulein induced an excitatory response. This effect was reversed by treatment with excess L-arginine. Similar results were obtained using cholecystokinin octapeptide in place of cerulein. In separate studies, cerulein generated increases in intracellular cAMP and cGMP levels in the SO. This indicates that the intracellular mechanism mediating cerulein-induced relaxation involves the production of cAMP and cGMP. On the other hand, treatment with L-NAME absorbed the increase in cAMP and cGMP levels by cerulein. These studies demonstrate that cerulein relaxes the canine SO mainly via NO, increasing intracellular cAMP and cGMP levels.

Animals↗

PubMed1998

Saliva level of free 3-methoxy-4-hydroxyphenylglycol in psychiatric outpatients with anxiety.

As a measurement of the level of anxiety in psychiatric outpatients with anxiety, we determined the saliva level of free 3-methoxy-4-hydroxyphenyleglycol (MHPG) using gas chromatography- mass spectrometry and scored the levels of anxiety with the Hamilton Anxiety Scale (HAS) in patients, before and after drug treatment with alprazolam for 1 week. The saliva level of free-MHPG at first visit to hospital was significantly higher than that of control individuals and disease control individuals and was reduced by alprazolam treatment for 1 week. There was no correlation between MHPG level and the HAS score at the first hospital visit. The MHPG levels after treatment correlated with the HAS scores. The reduction of the anxiety level as scored by the HAS correlated with the reduction of MHPG level. These results indicate that the free saliva MHPG level may be a useful indicator for assessing not only the level of anxiety, but also the response to drug treatment for anxiety in these patients.

Adult↗

PubMed1997

Antagonistic effects of OPC-14597, a novel antipsychotic drug, on quinpirole- and (-)-sulpiride-induced changes in evoked dopamine release in rat striatal slices.

The effects of a newly synthesized quinolinone derivative, 7-[4-(4-(2,3-dichlorophenyl)-1-piperazinyl) butoxy)-3,4-dihydro-2-(1H)-quinolinone (OPC-14597), a novel antipsychotic drug, on electrically evoked dopamine release in rat striatal slices were investigated. OPC-14597 (0.1-10 microM) had no effect on the dopamine release evoked in the striatal slices. The decrease induced by quinpirole, a dopamine receptor agonist, in evoked dopamine release was attenuated by superfusion with OPC-14597 (1 and 10 microM) which by itself had no effect on evoked dopamine release. The increase induced by (-)-sulpiride, a dopamine receptor antagonist, in evoked dopamine release was, moreover, also attenuated by 1 and 10 microM OPC-14597. These findings indicate that OPC-14597 antagonizes both dopamine agonist- and antagonist-induced changes in evoked dopamine release in striatal slices in rats.

Animals↗

PubMed1997

Ser-311-Cys polymorphism of the dopamine D2 receptor gene and schizophrenia--an analysis of schizophrenic patients in Fukuoka.

It has been suggested by Arinami et al. (1994) that there is a positive relationship between schizophrenia and the Cys311 polymorphism of the Dopamine receptor D2 (DRD2) gene. However, some recent reports do not support this relationship. The differing results could be due to two causes, [1] There may be a regional difference in the proportion of schizophrenia due to the Cys311 or [2] the control groups in the recent studies might have included young schizophrenics. Accordingly, an analysis of the age of schizophrenic patients in the Fukuoka region was undertaken. The Cys311 allele frequencies for the control group was 0.040 and for the schizophrenic group was 0.057, which were not statistically different. Although this data did not corroborate the above mentioned positive relationship, it was found that the allele frequency was higher statistically than in any previous report for both the schizophrenic and control groups. These findings indicate that the frequency of the Cys311 is biased geographically and that this must considered when investigating the occurrences of genetic variants and diseases.

Adult↗

PubMed1996

Isolation of a cDNA encoding the X enopus homologue of mammalian Cdc25A that can induce meiotic maturation of oocytes.

From a cDNA library of Xenopus laevis (Xl) oocytes, we isolated a cDNA encoding a putative protein phosphatase homologous to mammalian Cdc25A. Sequence analysis predicts that the Xl cdc25A gene product (Xl Cdc25A) consists of 521 amino acid residues and shares overall 55% identity with human Cdc25A. When its mRNA is injected into Xl oocytes, Xl Cdc25A can act as a potent M phase inducer.

Amino Acid Sequence↗

PubMed1996

[Clinical review of 105 cases of adrenal tumor, with special reference to incidental tumor].

We reviewed 105 patients with adrenal tumor diagnosed at our institute from January 1984 to December 1993. In 74 patients tumors were symptomatically diagnosed (the symptomatic group), while in the remaining 31 patients tumors were incidentally detected (the incidental group). In 5 cases of the incidental group, tumors were found at a routine health examination, whereas in the remaining 26 cases tumors were found during the examination or treatment for unrelated diseases. On both the incidental group and symptomatic group, higher right-to-left side ratio was noted in the laterality of tumors detected by ultrasound scanning. The size of tumors in the incidental group was significantly larger than that in the symptomatic group, but there was no significant difference in size between the tumors detected by ultrasound and those detected by CT scan in either the symptomatic group or in the incidental group. In the symptomatic group 71 patients (95.9%) were found to have functioning tumor, where the most common diagnosis was primary aldosteronism (44 cases), and 68 of the 71 patients received adrenalectomy. While in the incidental group 12 patients (38.7%) were found to have functioning tumor, where the most common diagnosis was pheochromocytoma (7 cases), followed by Cushing's syndrome (3 cases) including one case with so-called pre-Cushing's syndrome, and all of the 12 patients received adrenalectomy. Of 16 primary incidental adrenal tumors which did not have any hormonal functions, 5 tumors larger than 30 mm in diameter were resected and the remaining 11 tumors were followed up without operation. Since the incidence of incidental adrenal tumor may increase in the future, careful diagnosis and decision of indication for surgery are required.

Adolescent↗

PubMed1994

[A case of chronic traumatic dissecting aneurysm of the thoracic aorta].

A case of chronic traumatic dissecting aneurysm was reported. A 61-year-old man was admitted to our hospital for multiple trauma caused in traffic accident. MRI, performed for evaluation of the spinal injury, revealed dissection of the thoracic descending aorta by chance, seven months after injury. Retrospectively CT, just after admission, showed bleeding around the thoracic descending aorta. Replacement of thoracic aorta was performed after 33 months from the traffic accident, for enlargement of dissecting lumen accompanied with hoarseness. The postoperative course was uneventful and the patient returned to his daily life successfully.

Aortic Dissection↗

PubMed1993

Solitary pancreatic metastasis from renal cell carcinoma.

A rare case of resectable solitary pancreatic metastasis from a renal cell carcinoma is reported. The patient was a 57-year-old man who presented with epigastralgia. He had undergone a radical nephrectomy of the right side 30 months previously. The diagnosis of pancreatic metastasis was based on the patient's past history and angiographic demonstration of typical hypervascular tumor staining. Histological examination was confirmatory. The patient was successfully treated by pancreaticoduodenectomy followed by alpha-interferon administration. As of 6 months after surgery, he remains well.

Carcinoma, Renal Cell↗

PubMed1975

[Typical massive atelectasis after epidural anesthesia].

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Aged↗