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Biomedical subjects

K Ishimura

Publications and source records attributed to K Ishimura.

At least 91 records · Page 5Linked to original sources
PubMed1989

Further immunocytochemical study on the localization of aromatase in the ovary of rats and mice.

The precise localization of estrogen biosynthesis in the ovary of rats and mice were immunocytochemically studied using new antisera against aromatase cytochrome P-450. The positive reaction for aromatase was detected mainly on the granulosa cells of large, apparently preovulatory follicles. In addition, the cells of some corpora lutea showed very weak positive reaction but most corpora lutea were negative to the staining. Those cells such as the granulosa cells of smaller follicles, the theca interna cells, the interstitial gland cells, oocytes, peritoneal epithelial cells were entirely negative. These results indicate that in the ovary of rats and mice, the granulosa cells of preovulatory follicles are the main site for synthesis of estrogen from androgen which is provided by the theca interna cell and the interstitial gland cell.

Animals↗
PubMed1989

Increase in plasma noradrenaline concentration after the administration of phentolamine in the patients with "latent" left-sided heart failure.

We measured increments of peripheral venous pressure induced by dynamic leg exercise (delta VP) in 10 healthy subjects (Group C) and 70 patients with heart diseases which primarily affect the left-side of the heart. None of the subjects showed apparent symptoms of left- or right-sided heart failure. The patients were divided into 2 groups on the basis of delta VP, namely, Group N (delta VP less than 35 mmH2O, n = 30, normal reaction) and Group H (delta VP greater than or equal to 35 mmH2O, n = 40, abnormal reaction). We measured the increments of plasma concentrations of noradrenaline (delta NAPH) and adrenaline (delta APH) with infusion of phentolamine (PH). Parallel studies with nitroglycerin and prazosin supplied strong evidence that delta NAPH was brought about mainly by the blockade of alpha 2-receptors at the sympathetic nerve terminals. Thus, we estimated the degree of sympathetic nerve activity from the central nervous system by opening using PH the negative feed-back loop for noradrenaline (NA) release at the sympathetic nerve terminals, and this degree of sympathetic nerve activity was compared with the degree of delta VP. The results obtained were 1) there was a rough overall correlation between delta VP and delta NAPH in the subjects of Groups C, N and H, and 2) delta NAPH was significantly higher in Group H than in Groups C and N. These results suggest that much reliance can be placed on the measured increment of plasma NA concentration in response to the administration of PH in assessing the degree of enhanced sympathetic nerve activity in the patients with "latent" left-sided heart failure.

Adult↗
PubMed1988

Quantitative analysis of the distribution of serotonin-immunoreactive cell bodies in the mouse brain.

The distribution of serotonin neurons in the mouse brain was studied using a peroxidase-antiperoxidase (PAP) immunohistochemical method to obtain quantitative data on serotonin-containing cell bodies. The average total number of perikarya of serotonin neurons was about 26,000, of which about 17,000 cells (66.9%) were situated in the raphe system. The nucleus raphe dorsalis was the main region where a large number of serotonin neurons were present, and it contained about 9000 cells. Other than the raphe system, serotonin-immunoreactive perikarya were seen in the following regions: the reticular formation (18.9%), the lemniscus medialis (8.5%), the nucleus interpeduncularis (1.5%), the subpyramidal region (4.0%) and the periaqueductal gray (0.2%).

Animals↗
PubMed1988

Light and electron microscopic immunocytochemistry on the localization of 3 beta-hydroxysteroid dehydrogenase/isomerase in the bovine adrenal cortical cells.

The localization of 3 beta-hydroxysteroid dehydrogenase/isomerase (3 beta-HSD) was studied in bovine adrenal glands by light as well as electron microscopic immunocytochemistry, using anti-bovine adrenal 3 beta-HSD antibody. With light microscopy the cytoplasm of the glomerulosa cells was weakly immunostained, while that of the fasciculata-reticularis cells was intensely immunostained though both the capsular connective tissue cells and the medullary cells were entirely negative for this reaction. Electron microscopic immunocytochemistry revealed that the positive reaction products for 3 beta-HSD were present on the membrane of smooth endoplasmic reticulum of the cortical cells, especially that of the fasciculata and reticularis cells. Other cell organelles such as mitochondria and Golgi apparatus were entirely negative. The present results indicate that 3 beta-HSD is present in the membrane of smooth endoplasmic reticulum of bovine adrenal cortical cells.

3-Hydroxysteroid Dehydrogenases↗
PubMed1988

Serotonin reduction in the mouse neostriatum during hyperthermia-induced convulsions studied by immunohistochemistry.

Changes occurring in serotonin neurons during hyperthermia-induced convulsions were examined by means of a modified immunohistochemical method. All mice (8-12 weeks of age) exposed to the temperature of 50 degrees C had convulsions, showing a generalized tonic and/or clonic pattern. Immediately after the convulsions, the animals were perfused transcardially with a fixative. A significant reduction in serotonin immunoreactivity was observed in the neostriatum (caudate-putamen complex) of the mice which had hyperthermia-induced seizures, while the serotonin immunoreactivity remained unchanged in the neocortex and paleostriatum. These results suggest that serotonin may be an important mediator in the mechanism of hyperthermia-induced convulsions or that the susceptibility of serotonin neurons to a convulsive state is greatest in the neostriatum.

Animals↗
PubMed1988

Brain energy metabolism in two kinds of total asphyxia: an in vivo phosphorus nuclear magnetic resonance spectroscopic study.

Brain energy metabolism was studied in vivo by means of 31P-NMR spectroscopy in newborn mice during and after 20-minutes exposure to either pure carbon dioxide gas or nitrogen gas. In the N2 group, the brain ATP concentration remained almost normal throughout the experiment, while it showed a 30% reduction in the CO2 group. The brain concentration of phosphocreatine dropped to about 20% of the control value during the asphyxia in both groups, and its recovery was significantly delayed in the CO2 group compared to in the N2 group. Tissue acidosis and Pi accumulation were more remarkable and prolonged in the CO2 group.

Adenosine Triphosphate↗
PubMed1988

Response of peripheral venous pressure and plasma catecholamine concentration to supine leg exercise--a study in patients with mild congestive heart failure.

We measured the peripheral venous pressure (VP) in supine leg exercise in 25 "normal" subjects and 122 patients with primarily left-sided heart diseases (NYHA class I = 68, class II = 54 cases) to determine whether or not plasma catecholamine concentration would increase in patients with mild congestive heart failure, in response to dynamic exercise. Cardiac patients (n = 122) were divided into 2 groups on the basis of VP increment (delta VP): Group N had 60 patients with delta VP less than 35 mmH2O, and Group H had 62 patients with delta VP in excess of 35 mmH2O. Plasma concentrations of noradrenaline (NA) and adrenaline (A) were measured before and during leg exercise. The relation between delta VP, NA and A, and the relation between delta VP and increments of NA (delta NA) and of A (delta A) by leg exercise were studied in both the cardiac patients and the "normal" subjects (Group C). (1) NA at rest was 0.225 +/- 0.016 ng/ml (mean +/- SE) in Group C and 0.216 +/- 0.009 ng/ml in Group N. It was 0.468 +/- 0.026 ng/ml in Group H, which was significantly higher than in Group C (p less than 0.001), or Group N (p less than 0.001). (2) delta NA was 0.051 +/- 0.009 ng/ml (mean +/- SE) in Group C, 0.067 +/- 0.007 ng/ml in Group N, and 0.249 +/- 0.019 ng/ml in Group H. There was a statistically significant difference in delta NA between Groups C and H (p less than 0.001) and between Groups N and H (p less than 0.001). (3) There was no significant difference between the three groups in A at rest, or in delta A. (4) There was a correlation between delta VP and NA at rest (r = 0.614, p less than 0.001) and between delta VP and delta NA (r = 0.708, p less than 0.001). These data suggest that sympathetic nervous activity increased in the patients with high delta VP but without overt heart failure, and that the constriction of the capacitance vessels caused by an increase in NA could be at least one of the mechanisms involved in raising the delta VP in those patients.

Adolescent↗
PubMed1987

Immunocytochemical localization of calspectin (a non-erythroid spectrin-like protein) in thyroid glands of normal and TSH-treated rats.

The localization of calspectin (fodrin, a non-erythroid spectrin-like protein), which is known to bind calmodulin and F-actin, was detected in the thyroid gland of normal and TSH-treated rats by means of light-microscopic immunocytochemistry. Calspectin was demonstrated in the cytoplasm of the follicle epithelial cells especially along the baso-lateral plasma membrane in normal rats. In TSH-treated animals, in addition to the baso-lateral plasma membrane region, the apical plasma membrane region of the follicle epithelial cells also showed positive reaction to the immunostaining. These results suggest that calspectin, in conjugation with calmodulin and actin, play a role in the secretory activities including reabsorption activity of colloid of the follicle epithelial cell.

Animals↗
PubMed1987

Effects of phentolamine on response to supine leg exercise of peripheral venous pressure and plasma catecholamine concentration--a study in patients with mild congestive heart failure.

The present study examined the effects of phentolamine (PH) on the increments in peripheral venous pressure (delta VP), and of plasma noradrenaline (delta NA) and adrenaline (delta A) concentration, in response to supine leg exercise. Peripheral venous pressure and plasma catecholamine concentrations were measured at rest and during exercise, before and after intravenous injection of PH (0.1 mg/kg) in 10 healthy volunteers (Group C), and in 42 patients with primarily left-sided heart diseases but without apparent right-sided or left-sided heart failure (NYHA class I, II). These cardiac patients were divided into 2 groups on the basis of delta VP. Those with delta VP below 35 mmH2O comprised the normal group (Group N), and those with delta VP more than 35 mmH2O the abnormally high group (Group H). 1) In Group C, delta VP changed only slightly from 11.1 +/- 2.8 (mean +/- SE) to 4.9 +/- 1.7 mmH2O with an intravenous injection of PH. On the other hand, PH caused a significant decrease in delta VP from 22.2 +/- 2.3 to 10.4 +/- 2.3 mmH2O in Group N (p less than 0.001), and from 52.7 +/- 3.4 to 17.0 +/- 12.4 mmH2O in Group H (p less than 0.001). It was suggested that PH blocked the alpha-receptors of the systemic capacitance vessels, thereby inhibiting the constriction of these vessels. 2) Both NA at rest and delta NA before PH were significantly higher in Group H than those in Groups C or N. delta NA increased significantly after the PH injection in all 3 groups, i.e., from 0.038 +/- 0.013 (mean +/- SE) to 0.282 +/- 0.051 ng/ml in Group C, from 0.056 +/- 0.013 to 0.279 +/- 0.034 ng/ml in Group N and from 0.279 +/- 0.034 to 0.839 +/- 0.103 ng/ml in Group H. The increase in delta NA after PH was especially marked in Group H. It was suggested that the "sympathetic nervous activity" was increased in the patients with an impaired left ventricular pumping function. 3) PH caused a slight increase in delta A in all groups, but there was no significant difference in delta A before and after PH in the 3 groups.

Adult↗
PubMed1987

Immunocytochemical localization of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD), and its relation to the ultrastructure of steroidogenic cells in immature and mature rat ovaries.

Immunocytochemical localization of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) and its relation to the ultrastructure of steroidogenic cells were examined in mature and immature rat ovaries. In mature (8-10 weeks old) rat ovaries, the theca interna cells of secondary as well as Graafian follicles, and the interstitial gland cells were all strongly stained with anti-17 beta-HSD antibody. However, granulosa cells, corpus luteum cells, oocytes and peritoneal epithelial cells were negative against this staining. In the ovaries of 1-week-old rats, all these cells were negative to immunostaining for 17 beta-HSD. In the ovaries of 2-week-old rats, the theca interna cells of secondary follicles and the interstitial gland cells showed a positive reaction for the 17 beta-HSD activity. Electron microscopic examination demonstrated the presence of characteristic structures for steroid secretory cells such as many lipid droplets, well developed smooth endoplasmic reticulum, and oval mitochondria with tubular cristae in the theca interna cell of secondary as well as Graafian follicles and in the interstitial gland cell of mature rat ovaries. In the ovaries of 1-week-old rats, all the theca cells of the primary and secondary follicles were fibroblast-like in their shape and fine structure, and typical interstitial cells were not recognized. In the 2-week-old rats, some of the theca interna cells and interstitial cells were well differentiated in ultrastructure, showing characteristic features for steroid secretory cells. These findings indicate that by 2 weeks after birth, theca interna cells and interstitial gland cells acquire the ability for testosterone production as seen in mature rat ovaries.

17-Hydroxysteroid Dehydrogenases↗
PubMed1986

A radioimmunoassay for thymosin alpha-1.

A new radioimmunoassay (RIA) is described for the quantitation of thymosin alpha-1 (alpha-1). The assay employs an antiserum specific for the COOH-terminal half segment 15-28 of alpha-1, synthetic alpha-1-(15-28) as the hormone standard, and a radioiodinated N alpha-acetyltryrosyl-alpha-1-(15-28) as the tracer. Since alpha-1-(1-28) lacks a phenolic ring for direct radioiodination, the N alpha-acetyltyrosyl-alpha-1-(15-28) was synthesized by the solid-phase method. The peptide bears a Tyr in place of Lys in position 14 of the natural peptide. It showed full alpha-1-(15-28) immunoreactivity and its radioiodinated derivative served as tracer in the RIA. An anti-alpha-1-(15-28) antiserum was raised in a rabbit and was shown to recognize alpha-1-(15-28) or its tyrosyl analogue, and the peptide, alpha-1-(1-28). But it did not recognize other thymic hormones or the biologically active segment 32-36 of thymopoietin, or structurally unrelated peptides. It could also detect natural alpha-1 cross-reacting material in the cytoplasm of cultured human thymic epithelial cells as measured by indirect immunofluorescence. In the RIA, as little as 9 pg of alpha-1-(15-28) equivalents in a 50 microliter sample could be detected. In addition, alpha-1-(1-28)-like immunoreactivity was quantitated in 6 human thymus homogenates and ranged from 0.5 to 4.5 ng/mg of protein.

Amino Acid Sequence↗
PubMed1986

Granule cell deficit in the mouse cerebellum after total asphyxia.

The cerebellar granule cell continues to proliferate after birth in the mouse as well as in the human being. Total asphyxia in the neonatal period in 40 mice resulted in a 13% reduction in the granule cell number and a 7% reduction in the Purkinje cell number. Differential effects on granule cell and Purkinje cell populations were noted when particular cerebellar lobules were examined.

Animals↗
PubMed1986

Ultrastructural and immunohistochemical studies on steroid-secreting cells of testis and ovary of normal and 3-methylcholanthrene-treated mice.

The testis and ovary of normal and 3-methylcholanthrene-treated mice were studied ultrastructurally and immunohistochemically in order to learn whether steroid-secreting cells of the gonads are involved in drug metabolism. The steroid-secreting cells, i.e., Leydig cells of the testis, and theca interna cells, interstitial gland cells, and corpus luteum cells of the ovary of 3-methylcholanthrene-treated mice show a strong positive reaction to the antiserum against, hepatic microsomal cytochrome P-450, of liver which is the terminal oxidase of the drug-metabolizing enzyme complex. In addition, it was found that elements of smooth endoplasmic reticulum (SER) in drug-treated mice become well developed as compared with those in control animals. These findings indicate that the steroid secreting cells in testis as well as ovary are involved in the metabolism of both endogenous and exogenous chemical compounds.

Animals↗
PubMed1986

Immunocytochemical localization of 17 beta-hydroxysteroid dehydrogenase in porcine testis.

The immunocytochemical localization of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) in porcine testes was examined by applying an indirect-immunofluorescence method using an antiporcine testicular 17 beta-HSD antibody. Only the Leydig cells located in the interstitial tissue exhibited a positive immunoreaction for 17 beta-HSD: the germ cells and Sertoli cells located in the seminiferous tubules were entirely negative. These results suggest that, in porcine testis, the biosynthesis of testicular testosterone, the final step of which is the conversion of androstenedione to testosterone, takes place in the Leydig cells.

17-Hydroxysteroid Dehydrogenases↗