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Biomedical subjects

M Sakaue

Publications and source records attributed to M Sakaue.

68 records · Page 4Linked to original sources
PubMed1988

Novel type of monoclonal antibodies against cyclic GMP and application to immunocytochemistry of the rat brain.

A novel type of monoclonal antibodies against cyclic GMP were produced to study the immunocytochemical distribution of cyclic GMP in the rat brain. Cyclic GMP conjugated to bovine serum albumin with glutaraldehyde was used as an immunogen, and monoclonal antibodies were produced. The one monoclonal antibody which did not crossreact against other nucleotides was applied to the immunocytochemistry of the rat brain. Cyclic GMP immunoreactivities were distributed unevenly in the rat brain. The cerebellar cortex, hippocampus and cerebral cortex contained a high degree of cyclic GMP immunoreactivity, while most of the white matter was not stained. In the cerebellar cortex, stellate cells and Golgi cells showed intense immunoreactivities, but granule cells showed weak immunoreactivities. Approximately 60-80% of the Purkinje cells showed intense immunoreactivities, while the remaining ones showed only weak staining. The pyramidal cells in the cerebral cortex and hippocampus also showed intense immunostaining. Some glial cells adjacent to the Purkinje cells also stained. The nuclei of cyclic GMP-immunoreactive cells were not stained. These immunocytochemical distributions of cyclic GMP are in fairly good agreement with reported the biochemical data and the immunocytochemical distribution of guanylate cyclase. These monoclonal antibodies should be helpful for elucidating the physiological role of cyclic GMP in the brain.

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PubMed1987

Immunohistochemical localization of gamma-aminobutyric acid (GABA) in the rat pancreas.

The localization of gamma-aminobutyric acid (GABA) in rat pancreas was investigated using antiserum raised against GABA conjugated to bovine serum albumin with glutaraldehyde. Immunoreactive cells were only found in the center of the pancreatic islets, and these cells were surrounded by nonimmunoreactive cells. When two serial sections of rat pancreas were consecutively stained with GABA antiserum and with antibodies against insulin, both antisera stained the same population of endocrine cells within the islets. In rats pretreated with streptozotocin, a B-cell toxin, we observed a marked decrease in the number of cells exhibiting GABA-like immunoreactivity. These observations indicate that GABA is present in the B cells of rat pancreatic islets.

Animals↗
PubMedDate not supplied

A possible association of Pro12Ala polymorphism in peroxisome proliferator-activated receptor gamma2 gene with obesity in native Javanese in Indonesia.

BACKGROUND: Peroxisome proliferators-activated receptor gamma (PPAR gamma) is a nuclear hormone receptor that serves as a master regulator of adipocytes-specific genes contributing to adipocytes differentiation, susceptibility to obesity, and insulin sensitivity. The substitution of proline to alanine at codon 12 of the PPAR gamma2 gene (Pro12Ala polymorphism) is most frequently identified and the associations with diabetes, obesity, and other clinical parameters have been reported and discussed in several ethnic groups. Among native Javanese ethnicity, however, there is no report about this polymorphism. AIMS AND METHODS: Aims of this study were to estimate the allele frequency of the Pro12Ala polymorphism of PPAR gamma2 gene among native Javanese in Indonesia and to investigate the relationship between this polymorphism and obesity or diabetes. This study included 540 native Javanese subjects consisting of 337 diabetic patients and 203 normal glucose tolerance subjects. Both groups included totally 160 obese subjects (body mass index > or = 25 kg/m(2)). PCR-restriction fragment length polymorphism was used for the genotype determination. RESULTS: The allele frequency of Pro12Ala polymorphism in PPAR gamma2 gene among native Javanese is lower than that in other ethnic groups. No association is seen between the Pro12Ala and diabetes (0.01 vs 0.017%, p = 0.404), a trend of the higher BMI was observed in Pro12Ala carriers in nondiabetic subjects, although this association is limited by small numbers. CONCLUSION: In this study, no association is seen between the Pro12Ala polymorphism in PPAR gamma2 gene and diabetes; a weak association with obesity is seen.

Aged↗
PubMedDate not supplied

MKC-242, a novel 5-HT1A receptor agonist, facilitates cortical acetylcholine release by a mechanism different from that of 8-OH-DPAT in awake rats.

We have previously reported that 5-¿3-[((2S)-1,4-benzodioxan-2-ylmethyl)amino]propoxy¿-1,3-be nzodioxole (MKC-242), a potent and selective serotonin (5-HT)1A receptor agonist, exerts anxiolytic- and antidepressant-like effects in animal models and that the antidepressant-like effect may be mediated by postsynaptic 5-HT1A receptors. The present study, using a microdialysis technique, was undertaken to characterize in vivo the effect of MKC-242 on cholinergic neurons. Subcutaneous injection of MKC-242 (0.5-1.0 mg/kg), like the typical 5-HT1A receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT), increased extracellular acetylcholine (ACh) levels in the rat cerebral cortex. The increase in ACh release by MKC-242 was also observed in the hippocampus. The effect of MKC-242 on cortical ACh release was attenuated by pretreatment with the 5-HT1A receptor antagonists (10 mg/kg, s.c.) propranolol and N-tert-butyl-3-(4-(2-methoxyphenyl)piperazin-1-yl)-2-phenylpropana mide. The increase in cortical ACh release by MKC-242 was blocked by lesion of serotonergic neurons with 5,7-dihydroxytryptamine, whereas that by 8-OH-DPAT was not. Lesion of noradrenergic neurons with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine did not affect the MKC-242-induced increase in ACh release. These results suggest that systemic injection of MKC-242 facilitates in vivo ACh release via an activation of somadendritic 5-HT1A autoreceptors, and that MKC-242 and 8-OH-DPAT affect cholinergic neurons in the rat cerebral cortex via different mechanisms.

5,7-Dihydroxytryptamine↗
PubMedDate not supplied

Acute and subacute toxicity of 10B-paraboronophenylalanine.

The acute and subacute toxicities of 10B-paraboronophenylalanine (10B-BPA) were investigated in the rat, according to the Good Laboratory Practice Standard for safety studies on drugs in Japan. In the acute toxicity test of 10B-BPA, LD50 values of acidic 10B-BPA for intraperitoneal and subcutaneous injections were 640 mg/kg for male and 710 mg/kg for female rats, and more than 1,000 mg/kg for male and female rats, respectively. The LD50 values of neutral 10B-BPA for intraperitoneal and subcutaneous injections were more than 3,000 mg/kg for male and female rats. The difference in LD50 values between acidic and neutral 10B-BPA may be attributed to the acidity of material. From the subacute toxicity test, in which the rats were injected daily subcutaneously for 28 days, the following toxic effects of 10B-BPA were observed. Increase in ketone level in the urine was induced in all rats treated with 10B-BPA. High dose of 10B-BPA (1,500 mg/kg) induced increase in spleen weight and reticulocyte count, and decrease in hemoglobin count, thereby suggesting that 10B-BPA causes hemolysis. Increases in the leukocyte count and the ratio of neutrophils and lymphocytes were also observed in rats treated with a high dose of 10B-BPA. This may be attributed to local reactions at the injection site. There were no significant differences in the findings between control rats and rats treated with a low dose of 10B-BPA (300 mg/kg). Thus, low doses of neutral 10B-BPA may be available for use as a drug.

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