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M Moriya

Publications and source records attributed to M Moriya.

At least 19 recordsLinked to original sources
PubMed1995

Immunohistochemical localization of the calcium/calmodulin-dependent protein phosphatase, calcineurin, in the mouse testis: its unique accumulation in spermatid nuclei.

Immunohistochemical localization of a calmodulin-dependent protein phosphatase, calcineurin, was studied in the mouse testis in relation to previous observations showing that calmodulin is unusually rich in spermatogenic stages from mid-pachytene spermatocytes to elongating spermatids. The antibodies raised against calcineurin from scallop testis reacted with subunit B, but not subunit A, of calcineurin isoforms from mouse brain and testis. Indirect immunofluorescence using these antibodies on the mouse testis revealed positive reactions only in the nuclei of round or elongating spermatids: calcineurin started to accumulate in nuclei from the acrosomal cap phase, peaked at the initial stage of nuclear elongation, and decreased thereafter. There was almost no signal in the cytoplasm; spermatogenic cells at other stages, including spermatogonia, spermatocytes, mature sperm, and other somatic cells in the seminiferous tubules were totally negative. Immuno-electron microscopy gave the same result, on the basis of measuring the density of immunogold particles. These results suggest a role for calcineurin in remodeling of the nuclear chromatin in metamorphosing spermatids.

Animals↗
PubMed1995

Bulbar morphology and expression of bulbar dopamine and parvalbumin in experimentally-induced anosmic rats.

Morphological study was carried out in rats with olfactory dysfunction induced by deafferentation of serotonergic fibers in the olfactory bulb. With a computer capable of area measurements, olfactory bulbs of the anosmic rats were found to be decreased in size to 61% of control bulbs, and all bulbar layers were involved in the bulbar shrinkage. Given areas of each bulbar layer in control bulbs to be 100%, percentages of each bulbar layer in the anosmic rats were 23% in the olfactory nerve layer, 54% in the glomerular layer, 63% in the external plexiform layer, 83% in the internal plexiform layer and 81% in the granule cell layer. Dopamine-and parvalbumin-containing neurons were examined immunohistochemically in the experimentally-induced anosmic rats. As a result, immunoreactive neurons for these two chemical substances were significantly decreased in number (dopamine, 33% of control value; parvalbumin, 46% of control value). The present study, using an animal model of anosmia, provided quantitative data on the bulbar atrophy and showed effects of anosmia on expression of dopamine and parvalbumin in the bulb.

Animals↗
PubMed1994

Mutagenic potency of exocyclic DNA adducts: marked differences between Escherichia coli and simian kidney cells.

A single-stranded shuttle vector containing a single 3,N4-etheno-2'-deoxycytidine (epsilon dC) or 1,N2-(1,3-propano)-2'- deoxyguanosine (PdG) DNA adduct was used to investigate translesional DNA synthesis in Escherichia coli and simian kidney (COS) cells. The presence of either exocyclic adduct was associated with reduced numbers of transformants. In E. coli, this inhibitory effect could be overcome partially by irradiating cells with UV light before transformation. Translesional synthesis past both exocyclic lesions was accompanied by targeted mutations. For PdG, the primary mutagenic events observed in both hosts were PdG-->T transversions; in preirradiated E. coli, PdG-->A transitions were also observed. The targeted mutation frequency for single-stranded DNA that contained PdG was 100% in nonirradiated E. coli, 68% in preirradiated cells, and 8% in COS cells. In contrast, the targeted mutation frequency for single-stranded DNA that contained epsilon dC was 2% in nonirradiated E. coli, 32% in preirradiated cells, and 81% in COS cells. The primary mutations generated by epsilon dC in both E. coli and COS cells were epsilon dC-->A and epsilon dC-->T base substitutions. These observations appear to reflect the variable specificity of DNA replication complexes in incorporating bases opposite certain adducts. We conclude that DNA synthesis past the same DNA adduct can have strikingly different consequences in bacteria and mammalian cells, underscoring the importance of establishing the intrinsic mutagenic potential of DNA adducts in mammalian cells.

Animals↗
PubMed1994

Prominent expression of protein kinase C (gamma) mRNA in the dendrite-rich neuropil of mice cerebellum at the critical period for synaptogenesis.

It has been suggested that the expression of type 1 (gamma) protein kinase C(PKC) plays an active role in synaptogenesis. In situ hybridization assisted by an original computer image analysis technique (superimposition method) enabled the identification of PKC mRNA expression in the dendrite-rich neuropil area of the cerebellum. This study revealed prominent expression of PKC mRNA in the dendrite-rich neuropil area of the cerebellum at the critical period for synaptogenesis compared with adult mice cerebellum. Therefore, it is suggested that PKC mRNA in the dendrites of Purkinje cells plays an important role in synaptogenesis.

Algorithms↗
PubMed1994

Lipid interference with fluorometric assay of DNA in adipose tissues under various conditions.

Interference by lipids with fluorometric assay of DNA in adipose tissues using Hoechst 33258 was investigated. Mixed glycerides shifted the emission maximum of standard DNA and induced a dose-dependent increase in fluorescence intensity. Glycerides in the samples containing a known concentration of DNA yielded erroneously higher DNA concentrations. The DNA concentrations obtained from acetone-defatted white and brown adipose tissues (WAT and BAT) were lower than those of non-defatted ones, while DNA content did not differ in low lipid-containing skeletal muscle between defatted and non-defatted samples, indicating that large amounts of lipids interfere with DNA measurement using Hoechst 33258 and that acetone defatting is a simple method to avoid this interference. Using this defatting method, the cellularity of WAT and BAT was estimated in rats under various experimental conditions. Cold-acclimation and repetitive immobilization stress decreased the body weight gain and the epididymal WAT weight. Sucrose overfeeding increased WAT weight but not body weight. These treatments of 4 weeks' duration did not induce any significant difference in WAT cell number from controls, while cold-acclimation increased the tissue cell number as well as the BAT weight.

Acetone↗
PubMed1994

A new computer analysis technique using automatic threshold selection algorithm, available for quantitative estimation of the immunostained dendrites of the cerebellum.

We developed a new computer image analysis technique with application of an automatic threshold selection (ATS) algorithm which was successfully used in the quantitative evaluation of a highly complex texture of immunostained brain tissue. We applied this new method for estimation of the volume of the Purkinje dendrites, which were immunohistochemically stained for inositol 1,4,5-trisphosphate receptor protein (P400), and demonstrated a significant reduction of the dendritic arborization of the Purkinje cells of a neurological mutant mouse. Wriggle mouse Sagami, which would appear normal if stained with conventional methods such as H-E and Nissle staining.

Algorithms↗
PubMed1994

[Nutritional adaptation in brown adipose tissue thermogenesis--with special reference to overfeeding and iron deficiency].

The effect of sucrose overfeeding and low iron diet on brown adipose tissue (BAT) thermogenesis of rats has been investigated from the view point of in vitro BAT oxygen consumption and BAT fatty acids (FA) compositions in rats. Control group was fed on a standard diet with tap water, sucrose group was on the standard diet and 32% sucrose solution, and iron deficient group on a low iron diet with tap water. In vitro interscapular BAT thermogenesis as estimated by oxygen consumption was measured in minced tissue blocks in Krebs-Ringer phosphate buffer using a Clark oxygen electrode. In sucrose overfeeding rats, caloric intake was greater than in controls, but did not differ body weight. Interscapular BAT weight and DNA content were greater. Colonic and tail skin temperatures were higher. Basal oxygen consumption was higher. Noradrenaline- and glucagon-stimulated oxygen consumptions did not differ when expressed per DNA, but significantly greater per whole tissue pad. Both BAT-triglyceride (TG) and -phospholipid (PL) levels were higher. Polyunsaturated FA were lower, while monosaturated FA were higher in both BAT-TG and -PL. In iron deficient rats, BAT weight and DNA content were higher. Colonic and tail skin temperatures did not differ. Although basal oxygen consumption did not differ, noradrenaline-stimulated oxygen consumption was less per DNA, but did not differ per whole tissue pad, while glucagon-stimulated oxygen consumption was less when expressed per DNA, as well as whole tissue pad. Cold-tolerance as assessed by the fall in colonic temperature at 0 degree C was decreased. BAT-TG and -PL levels did not differ. Polyunsaturated FA were higher in both BAT-TG and -PL. These findings indicated that sucrose-induced overfeeding enhances BAT thermogenesis mainly by tissue hyperplasia, while iron deficiency suppresses BAT thermogenic response, although it causes the compensatory tissue hyperplasia.

Adaptation, Physiological↗
PubMed1994

Studies on the inferior phrenic vein of rats: the probability of its being a collateral route of blood from the lower portion of the body to the heart.

The principal aim of this study was to elucidate key features of the inferior phrenic vein (IPV) of adult rats to determine whether the IPV has the potential to function as a collateral return route conveying blood from the lower portion of the body to the heart, bypassing the subhepatic vein segment of the inferior caval vein. In rats, the IPVs on both sides were found to reveal a symmetric appearance. They were both composite vessels, being made up of two fellow subvessels, the sternocostal and the lumbocostal veins, which in turn anastomosed in tandem in their periphery with each other, formed a collateral route bridging the interval between the suprarenal and the hepatic vein segments of the inferior caval vein. In rat embryos of E17.5, the sternocostal and lumbocostal veins of the IPV were observed to have been well developed, forming tandem anastomoses more clearly than in adults, thus connecting the subcardinal vein to the hepatic vein segment of the inferior caval vein. This fact substantiates our supposition that the rat's IPV originally has the potential to act as a collateral returning route which allows blood to bypass the subhepatic vein segment of the inferior caval vein.

Animals↗
PubMed1992

Prominent expression of type 1 (gamma) protein kinase C in Purkinje cells located in the "central mass" of Reeler mutant mouse cerebellum as revealed by a computer image analysis technique.

In Reeler mutant mice, cerebellar Purkinje cells exhibit abnormal synaptogenesis. In this study, Purkinje cells in the "central mass" with abnormal afferent connections were compared with those located in their normal position in the cortex in terms of immunoreactivity for type 1 (gamma) protein kinase C. A "computer image analysis technique" was developed for the purpose of this quantitative study, and it revealed that the immunoreactivity in the central mass was significantly higher than that in the cortex. The results suggest that type 1 (gamma) protein kinase C may be related to the abnormal synaptic formation of the Purkinje cells.

Animals↗
PubMed1992

Alpha 1-adrenoceptor blocking activities of bevantolol hydrochloride(NC-1400) and labetalol in rat isolated thoracic aorta--do they distinguish between subtypes?

1. alpha 1-adrenoceptor blocking activity of bevantolol(NC-1400) was tested in the rat thoracic aorta, comparing with that of labetalol. 2. In alpha 1-adrenoceptor blocking activity, bevantolol(NC-1400) was 1/20th as potent as labetalol. 3. The pA2 values of bevantolol(NC-1400) and labetalol estimated in the rat thoracic aorta were compared with those in the rabbit thoracic aorta, which were reported by Takayanagi et al. [Takayanagi I., Kizawa Y., Iwasaki S. and Nakagoshi A. (1987) Gen. Pharmac. 18, 87-89]. 4. The pA2 values of bevantolol(NC-1400) and labetalol were approximately 1 order of magnitude higher in rat aorta than in rabbit aorta, suggesting that both the drugs distinguish between subtypes of alpha 1-adrenoceptors.

Adrenergic beta-Antagonists↗
PubMed1992

Effect of ageing on alpha 1A-adrenoceptor mechanisms in rabbit isolated bronchial preparations.

Effect of aging on alpha 1A-adrenoceptor mechanisms in rabbit bronchial preparations was studied. The potency (pD2 value) of norepinephrine increased with age from 5 to 13 weeks and thereafter did not alter with age from 13 to 180 weeks. The affinity of norepinephrine (pKA value) and of a selective alpha 1A-adrenoceptor blocker, 5-methylurapidil (pA2 value) did not alter with age. Efficacy of norepinephrine was proportional to receptor reserve (pD2-pKA). These results suggest that age-related changes in alpha 1A-adrenoceptor mechanisms are due to changes in receptor reserve or total concentration of receptors, but not to changes in affinity of drugs to alpha 1A-adrenoceptors and in contraction mechanisms.

Aging↗
PubMed1992

Branches of the internal thoracic artery of rats supplying the heart, the sinus regions and the brachiocephalic veins.

Branches of the internal thoracic artery (ITA) of rats which supply the heart, the sinus regions (see Terminology 1) and the brachiocephalic veins, were macroscopically studied. Two major branches of the ITA, the pericardiacophrenic artery and the descending ramus of the bronchoesophageal artery, were found supplying branches to these central portions of the cardiovascular system (see Table 1). They constituted, together with the ordinal coronary arteries, a system of dual blood supply to the heart as reported by Grant & Regnier (1926), Halpern et al. (1953, 1954) and Hebel & Stromberg (1986). This finding also supports a proposal of Grant & Regnier (1926) that the rat ITA emits cardiac branches which should be classified on the vertebrate scale to the caudal or extracoronary artery. Branches of the ITA to the heart, the sinus regions and to the brachicephalic veins were found to be classified into 2 major groups depending on their choice of entrance--arterial portal and venous porta; the latter was further divided into 3 subgroups depending on their selection of the (lateral or pulmonary or esophageal) mesocardium for traveling to the venous porta (see Table 2).

Animals↗
PubMed1992

A macroscopical study of the inferior phrenic artery of female rats, with reference to the embryological background of occurrence of the genital artery from this artery.

The principal aim of this study was to elucidate the general features of the inferior phrenic artery (IPA) of female rats which retain the original embryonic configuration of this artery. The artery of the right side was found to be detached from the renal artery, while that of the left side arose from the aorta. Between these fellow arteries, however, no essential morphological differences were discernible. At some point not far from their origin, they were found to break up into the ascending, suprarenal, suprareno genital and descending arteries. The ascending artery of the right side coursed along with the phrenic nerve, and vascularized a greatest portion of the total area of the partes sternalis et costalis of the diaphragm. Furthermore, the artery was found to be intimately associated with the inferior caval vein. Thus, it could be assumed that this artery of adult rats has been embryologically related to the musculus diaphragmaticus, transverse septum, ventral pleuroperitoneal fold, and the caval venous mesentery. The suprarenal artery took its course along the superior margin of this gland to reach the lateroinferior part of the pars costalis of the diaphragm. Its course and destination strongly indicates that in its development the suprarenal artery has been intimately related to the formation of the ventral pleuroperitoneal fold. The suprarenogenital artery was characterized as giving off a genital branch which entered first the diaphragmogenital ligament, and then took a descending course toward the ovary, in a quite similar manner of origin and course to those of the aberrant gonadal (testicular and gonadal) arteries observed in Japanese human adults (Shinohara et al., 1990; Hanie, to be published). The descending artery was observed to be closely associated with the major splanchnic nerve and the celiac ganglion. The variability of arteries of the IPA of female rats and also of humans, seems to reflect dramatic changes which have occurred in the early stages of development, and have influenced more or less the morphology of the uppermost abdominal anlages of the followings: transverse septum, musculus diaphragmaticus, dorsal and ventral pleuroperitoneal folds, suprarenal gland and celiac ganglion, urogenital organs, inferior caval vein in the caval venous mesentery. In conclusion, it could be said that the anatomy of female rats provide us valuable clues as to the essential configuration of the IPA of humans and the relationships of the IPA to structures which are thought to be directly involved in the development of this artery.

Adrenal Glands↗
PubMed1991

Abnormalities of foliation and neuronal position in the cerebellum of NZB/BINJ mouse.

To analyze developmental abnormalities related to neural migration in the NZB/BINJ mouse, the pattern of cerebellar foliation and neural position were compared with that of a normal mouse (C57BL/6J). Three abnormalities of cerebellar foliation--(1) lobe isolated from other cerebellar lobes, (2) lobes imbalanced in relative amounts or ratio of granular cell layer and molecular layer, (3) lobes in which some Purkinje cells and the molecular layer was embedded in the granular cell layer--were observed in NZB/BINJ mice. These morphological abnormalities were not limited to a specific lobe. On the other hand, abnormalities of neural position were observed in both granule and Purkinje cells. The pattern of ectopically-situated granule cells, in general, could be divided into 3 types: (1) large cell clusters extending from granular cell layer to the pia mater or middle part of the molecular layer, (2) clusters of various sizes scattered within the white matter and (3) clusters formed by combination of granule cells extending from two opposed granular cell layers to the molecular layer. The pattern of ectopically-situated Purkinje cells could be divided into 4 types: (1) ectopia of a group of cells from one part of the Purkinje cell layer, (2) ectopia of a single Purkinje cell observed in the molecular layer, (3) single Purkinje cell scattered within the white matter accompanied by clusters of ectopic granule cells and (4) ectopic Purkinje cells embedded in the granular cell layer. The abnormalities in position of both granule cells and Purkinje cells was not limited to a particular cerebellar lobe.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Alpha 1A-adrenoceptors in rabbit bronchus.

In the presence of propranolol, bronchial preparations from rabbits were markedly contracted by norepinephrine and phenylephrine but only slightly by clonidine. The contractile responses to norepinephrine were inhibited by prazosin and by high concentrations of yohimbine. The concentration-response curve of norepinephrine was shifted in parallel by WB4101 and 5-methylurapidil but not by 60-min treatment with chloroethylclonidine. These results suggest strongly that norepinephrine-induced contraction of rabbit bronchus is mediated through alpha 1A-adrenoceptors. Furthermore, cyclooxygenase inhibitors did not influence the response to norepinephrine, so norepinephrine-induced contraction is considered not to be mediated through the release of prostaglandins.

Adrenergic alpha-Antagonists↗
PubMed1991

Effects of ageing on nicotine-induced contraction and substance P-like materials release in guinea-pig bronchus.

1. Effects of ageing on nicotine-induced contraction and release of substance P-like materials in the bronchial preparations from guinea-pigs of different ages were studied. 2. The pD2 value (potency) of nicotine decreased with age from 10 to 100 weeks. The pD2 value of substance P did not change with age suggesting that substance P receptor mechanisms do not alter with age. 3. The amount of substance P-like materials released by nicotine (10(-4) M) decreased with age from 10 to 100 weeks, supporting our previous findings that nicotine contracts the guinea-pig bronchus through the release of substance P-like materials. 4. These results suggest that the age-related decrease in the pD2 value (potency) of nicotine is due to the reduction in the amount of substance P-like materials released by nicotine.

Aging↗
PubMed1991

Effect of ageing on response to nicotine in rabbit bronchial preparation.

1. Effect of ageing on the response to nicotine was tested in the bronchial muscle preparations from 5, 13, 100 and 125 week-old rabbits. The pD2 value (potency) of nicotine significantly increased in the preparation from the 125 week-old rabbits. No age-related change was found in the pD2 value of carbamylcholine or pA2 value of atropine. 2. No age-related change in characteristics of nicotine receptors. Choline acetyltransferase activity, the amount of acetylcholine released by nicotine and acetylcholineesterase activity decreased in the preparations from the 125 week-old rabbits. 3. Decrease in the pD2 value of nicotine in the preparation from the older rabbit is due to a decline in choline acetyltransferase activity followed by a reduction in the acetylcholine released, and not to a change in characteristics of nicotine receptors. 4. These results also suggest that enzymes may be influenced more easily with age than drug receptors.

Acetylcholine↗