Biomedical subjects

H Kitagawa

Publications and source records attributed to H Kitagawa.

At least 361 records · Page 20Linked to original sources

PubMed1989

An immunohistochemical study on the embryonic development of renin-containing cells in the mouse and pig.

The prenatal occurrence and distribution of renin-containing (RC) cells were investigated immunohistochemically in mouse and pig embryos. The RC cells of the mouse embryo were first observed at the 13th day of gestation at the walls of the renal, the mesonephric, the adrenal, the abdominal arteries, the adrenal glands and the testis. As the gestation of the mouse progressed, the RC cells had a tendency to localize in areas of the vascular pole of the metanephric glomerulus. In pig, when CRL was 0.8-2.0 cm, RC cells first appeared at the ventral walls of the dorsal aorta, the omphalo-mesenteric (i.e., the cranial mesenteric), the mesonephric, the mesonephric afferent glomerular arteries/arterioles and the inside of the mesonephric glomerulus. As the length of the pig embryo increased, no renin-immunoreactivity could be demonstrated at the degenerated mesonephros, while in the metanephros marked immunoreactivities were found only at the terminal regions of intralobular arteries, i.e., afferent arterioles or the vascular pole of the glomerulus.

Animals↗

PubMed1989

Partial purification of gelatinases and effect of anti-inflammatory drugs on the tumor necrosis factor-stimulated production of active gelatinase by granulation tissue in culture.

Gelatinases produced by granulation tissue in culture were separated into two fractions when the conditioned medium was chromatographed on diethylaminoethyl-Sephacel; one contained latent and active gelatinases with molecular weight of about 74 kDa (low-Mr gelatinase), and the other contained an active gelatinase with molecular weight of about 112 kDa (high-Mr gelatinase) as estimated by gel filtration on Sephadex G-150. The former was unbound and the latter was bound to Zn-chelating Sepharose. Both low- and high-Mr gelatinases, however, occurred in mainly two bands corresponding to molecular weights of 64 and 57 kDa on sodium dodecyl sulfate-substrate polyacrylamide gel electrophoresis. Recombinant human tumor necrosis factor-alpha (TNF) markedly enhanced the production of gelatinases, especially high-Mr active gelatinase. Dexamethasone and hydrocortisone strongly suppressed TNF-mediated production of high-Mr active gelatinase, whereas indomethacin, piroxicam and mepacrine had no effect. The results suggest that steroidal anti-inflammatory drugs suppress a rapid collagen breakdown in granulation tissue through their inhibitory actions--one of which is the suppression of active gelatinase production enhanced by cytokines including TNF.

Animals↗

PubMed1989

[Anticholinergic properties of oxitropium bromide (Ba 253) and its metabolites].

Anticholinergic properties of oxitropium bromide (Ba 253) were compared with those of atropine and ipratropium bromide (Sch 1000). The metabolites of Ba 253 (Ba 941, BEA 1125), the decomposition product (Ba 250), and the impurity (Ad 187) were also studied. In rat salivary activity, gastric secretion and rabbit gastric-motility, the anticholinergic activities of parenterally administered Ba 253 were 2.3 to 11.8 times and 1 to 2 times stronger than that of atropine and Sch 1000, respectively. The mydriatic and antisecretory actions of Ba 253 (p.o. or i.d.) were 1/7 and 1/47 those of atropine, respectively. In isolated rat stomach, guinea pig gallbladder and ileum, the anticholinergic activity of Ba 253 is similar to that of atropine. Inhalation of Ba 253 aerosol prevented ACh- and histamine-induced cough in guinea pigs, and its potency was 1/5 that of atropine or as the same as that of Sch 1000. In the isolated guinea pig trachea and ileum, the potencies of the anticholinergic activities of Ba 250 and Ad 187 were the same as that of Ba 253, but those of the other metabolites were very weak. These results suggest that the anticholinergic activity of Ba 253 is stronger than that of atropine when parenterally administered, and it cannot distinguish between the subtypes of muscarinic receptors.

Animals↗

PubMed1989

Morphology of blood cells in carp (Cyprinus carpio L.).

The morphology of blood cells in the carp was investigated by light and electron microscopy. Erythrocytes, thrombocytes, lymphocytes, granulocytes and monocytes were identified as the peripheral blood cells. Thrombocytes were round to long oval, each containing vesicular and microtubular structures and an oval nucleus with abundant heterochromatins. Lymphocytes were divided into three types in size, small, medium and large. Some of the small and medium lymphocytes were alpha-naphthyl-acetate esterase (ANAE) positive, while large lymphocytes were pyroninophilic. Granulocytes were distinguished into three types (type I, type II and type III) according to the morphology of the nucleus and granules. Type I granulocytes possessed lobulated nuclei and a large number of cytoplasmic granules, each of which was oval and contained electron-dense materials and a crystalloid. Type II granulocytes had small eccentric nuclei and were subdivided into IIa and IIb granulocytes by electron microscopic analysis. Granules of type IIa granulocytes were furnished with an electron-dense rim. Granules of type IIb granulocytes were larger than those of type IIa, containing randomly distributed electron-dense and electron-lucent materials. Type III granulocytes possessed round nuclei and a few large granules. The granules were filled with regularly arranged fibriform materials and some needle-like structures. Monocytes were morphologically similar to those of mammals.

Animals↗

PubMed1989

Effects of ligation of the ductus deferens on the fowl epididymal region.

The effects of ligation of the ductus deferens on the epididymis in the fowl were studied histochemically and immunohistochemically to reveal the mechanisms of sperm disposal. At one week post-ligation, the lumina of the rete testes (RT) and the efferent ductules (ED) were distended and filled with densely accumulated spermatozoa. Macrophages and foreign-body giant cells were aggregated in and around the accumulations. The epithelium regressed in the initial portion of the RT with the invasion of fibroblasts and heterophiles into the lumen. The other part of the epithelium was penetrated by many spermatozoa. Numerous lymphocytes and plasma cells infiltrated into the interstitium. At 4 weeks, larger number of spermatozoa agglutinated in the lumen, and large masses of foamy cells and proliferated connective tissue protruded into the lumen. At 8 weeks, large masses of foamy cells were noted. The connecting ductules or the epididymal duct showed no marked changes after ligation. The epithelium of the ED showed weaker or no acid phosphatase activity after ligation. Immunoglobulin G-containing cells increased in number in the interstitium. These results showed that ligation of the ductus deferens in the fowl causes granuloma in the RT and ED, and that epithelial cells, macrophages and granuloma are engaged in the removal of spermatozoa. The participation of antibody is suggested in the sperm disposal processes.

Animals↗

PubMed1989

Clinical studies on canine dirofilarial hemoglobinuria: measured and calculated serum osmolalities and osmolar gap.

Serum osmolalities and osmolar gap were determined in 43 normal healthy beagles (control group) and 40 dogs with dirofilarial hemoglobinuria (hemoglobinuria group). In the control group, the measured and calculated serum osmolality levels were in the means of 296 +/- 5 (SD) mOsm/kg and 293 +/- 6 mOsm/kg respectively, showing an osmolar gap less than 10 mOsm/kg. In the hemoglobinuria group, the measured serum osmolality ranged from 272 to 370 mOsm/kg. A considerable number of dogs had normal serum osmolalities in spite of severe intravascular hemolysis, suggesting that the changes in serum osmolality would not be the direct cause of intravascular hemolysis. The measured serum osmolality (331 +/- 28 mOsm/kg) was significantly higher in 11 dogs which died after a surgical removal heartworms than in 29 dogs which recovered after the removal (302 +/- 17 mOsm/kg). The calculated serum osmolality level was 296 +/- 16 mOsm/kg in 24 recovered cases, and 304 +/- 22 mOsm/kg in 10 fatal cases. The osmolar gap stayed in the normal ranges of 5.4 +/- 5.9 mOsm/kg in recovered cases, but it attained a higher level of 22.7 +/- 8.9 mOsm/kg in fatal cases, suggesting poor prognosis in cases with large osmolar gaps. There were significant positive correlations between the measured serum osmolality and osmolar gap, serum sodium, potassium, BUN, GOT, GPT, creatinine, bilirubin and plasma hemoglobin values, as well as between the osmolar gap and serum potassium, BUN, GOT, GPT, creatinine and bilirubin values. The plasma hemoglobin concentration fell markedly without significant change in serum osmolality 20 hr after the heartworm removal.

Animals↗

PubMed1989

Prevention of adverse reactions following milbemycin D administration to microfilaremic dogs infected with Dirofilaria immitis.

Some adverse reactions such as shock-like reaction and dirofilarial hemoglobinuria (caval syndrome) occasionally occurred in microfilaremic dogs following milbemycin D (Milbe) administration. This study was carried out to seek the prevention of these adverse reactions. In two groups containing 16 and 9 dogs respectively which were administered either chlorpheniramine maleate (1 mg/kg) or indomethacin (2.5 mg/kg) simultaneously with Milbe (1 mg/kg), the incidence of clinical signs such as the pale color of the visible mucous membranes, respiratory disorders, caval syndrome and shock-like reaction as well as changes in clinical parameters such as RBC and WBC counts, WBC profile and serum total protein, were almost equal to that observed in the group administered Milbe alone. In 41 dogs administered prednisolone (1 mg/kg) simultaneously with Milbe (1 mg/kg), no shock-like reaction was observed. Changes in clinical parameters were different from those in the group administered Milbe alone, whereas some clinical signs of adverse reactions, including caval syndrome, were observed. These results indicated that prednisolone was effective for prevention of the shock-like reaction in microfilaremic dogs induced by Milbe.

Animals↗

PubMed1989

Roles of gastric acid secretion and motility in gastric mucosal lesion formation induced by water-immersion stress in rats.

The roles of gastric acid and motility in gastric mucosal lesion formation induced by water-immersion stress were studied pharmacologically in rats. Gastric acid secretion and motility increased markedly during water-immersion, and mucosal lesions were formed. Cimetidine inhibited the increase in gastric acid secretion, but papaverine inhibited the increases in both acid secretion and motility. Both agents prevented the formation of mucosal lesions. In acid perfused rats, the increase in motility and lesion formation induced by water-immersion stress were prevented by papaverine, but not by cimetidine. These results suggest that the increases in both acid secretion and motility play important roles in the formation of mucosal lesions induced by water-immersion stress in rats.

Animals↗

PubMed1989

Gastric mucosal protective action of endothelium-derived relaxing factor.

The change in the endothelial function by the application of 0.6 N HCl and the effects of endothelium-derived relaxing factor (EDRF) inhibitors and nitrites on HCl-induced lesions were studied to clarify the effect of EDRF on gastric lesions in rats. The EDRF-induced increase in the gastric mucosal hemodynamics induced by vagal stimulation or intra-arterial administration of acetylcholine was inhibited by the EDRF inhibitors or removal of endothelial cells. Topical application of 0.6 N HCl on the exposed gastric mucosa abolished the response of the mucosal hemodynamics to acetylcholine or vagal stimulation. Gastric lesions induced by 0.45 N HCl were enhanced by EDRF inhibitors or removal of endothelial cells from gastric submucosal arterioles.

Animals↗

PubMed1989

Histological study on seminal plasma absorption and spermiophagy in the epididymal region of domestic fowl.

Absorption of seminal plasma and spermiophagy in the fowl epididymal region were studied ultrastructurally and histochemically. Epithelial cells of the rete testis had sparse coated vesicles and rarely showed spermiophagy. Many macrophages in the lumen of the rete testis actively phagocytosed spermatozoa. Nonciliated cells in the proximal efferent ductules had well-developed microvilli, coated vesicles, numerous tubular structures, and lysosomes in their apical cytoplasm. They rarely contained fragments of spermatozoa. Intense alkaline phosphatase activity was observed at the luminal borders of these cells. Ciliated cells had no features indicating active absorption of seminal plasma. Epithelial cells of the connecting ductules and epididymal duct had numerous microvilli, a few vesicles, and small lysosomes. They did not contain spermatozoa. Intense acid phosphatase activity was observed on the luminal and lateral surfaces of the epithelial cells of the connecting ductules and epididymal duct. After injection of horseradish peroxidase into the excurrent ducts, a large amount of reaction product was detected in the vesicles and tubular structures of the nonciliated cells of the proximal efferent ductules. These results suggest that the absorption of seminal plasma occurred mainly in the efferent ductules, and that spermiophagy by macrophages occurred in the rete testis in the fowl epididymal region.

Absorption↗

PubMed1989

Effects of epidural electrical stimulation modalities on spinal cord function and morphology in cats.

The safety of direct electrical stimulation to the spinal cord as used in spinal cord monitoring is controversial. This investigation was undertaken to determine the critical condition of continuous electrical stimulation over a period of 30 min with varying intensities and pulse durations, and the level of safety of intermittent stimulation of 100 pulses with 10 mA current of 0.3 msec duration with varying resting intervals. The spinal cord was evaluated by spinal cord evoked potentials (SCEP) recording and histological examination. The intensity of continuous stimulation greater than 10 mA of 0.3 msec duration resulted in permanent changes in SCEP, focal colliquative necrosis of the cord, and acceleration of the permeability of the intrinsic vessels. In the intermittent stimulation with 1-min resting intervals, spinal cord lesions were not observed.

Action Potentials↗

PubMed1989

[Changes in 5-HT2 receptor density induced by repeated treatment with 5-HT uptake inhibitor or 5-HT agonist].

It has been known that many antidepressant drugs which have serotonin (5-HT) antagonistic activities and 5-HT antagonists can induce the reduction of 5-HT2 receptor binding by their acute or successive administration. We investigated the effects of repeated treatment with 5-HT agonists on 5-HT2 receptors in rat cerebral cortex. We used citalopram as selective 5-HT uptake inhibitor, 5-hydroxytryptophan as 5-HT precursor, and 5-methoxy-N,N'-dimethyltryptamine as 5-HT2 agonist. The 5-HT2 receptor density was decreased by repeated treatment with these respective drugs. So it may be supposed that the reduction of 5-HT2 receptor binding is induced not only by 5-HT antagonists but also by 5-HT agonists.

5-Hydroxytryptophan↗

PubMed1989

Effects of repeated dosing of zopiclone on endocrine system in male rats.

The effects of a minor tranquilizer, zopiclone, on endocrine system in male rats were assessed to clarify the mechanisms whereby large doses of zopiclone may induce testicular damage. 1) Zopiclone had no significant effect on plasma and tissue levels of hormones of the hypophyseo-gonadal or -thyroid system in rats given 10, 100 and 250 mg/kg/day orally for 28 days. 2) Rats given zopiclone in doses of 10 and 100 mg/kg/day orally for 14 days had lowered serum levels of PGE2 and PGF2 alpha but the testicular PGF2 alpha concentration remained unchanged. Therefore, oral administration of high doses of zopiclone to rats has no evident influence on endocrine system related to male reproduction. And these findings support our previous paper that repeated dose of zopiclone cause no significant change in plasma or epididymal TS levels, nor to any change in lipid peroxidation in testicular tissues.

Animals↗

PubMed1988

Dog liver glutathione S-transferase and its strong immunoreactivity with rat transferase-P(7-7).

Dog liver cytosolic glutathione S-transferases (GSTs) were investigated to characterize their properties in comparison with rat liver transferases. Dog liver GSTs after the glutathione affinity column chromatography showed three subunit bands on SDS-polyacrylamide gel electrophoresis. These three subunits, designated as Yd1 (mol.wt 26,000), Yd2 (mol.wt 27,000) and Yd3 (mol.wt 28,000), were distinctly different from rat liver GST subunits, i.e. Ya(1) (mol.wt 26,500), Yb1(3)/Yb2(4) (mol.wt 27,500) and Yc(2) (mol.wt 28,500). Western blot analysis revealed that Yd1, Yd2 and Yd3 were immunoreacted with anti-rat GST 7-7, 1-1 and 3-3 antibodies, respectively. Four transferase activity fractions, I (pH greater than 7.63), II (pH 6.92), III (pH 5.80) and IV (pH 5.65), were obtained from affinity purified GSTs by chromatofocusing. Each fraction exhibited a characteristic substrate specificity. GST-II, III and IV were all strongly immunoreacted with anti-rat GST 7-7 antibody by immunoblotting, thus suggesting the occurrence of the heterogeneity of transferases immunologically related to rat GST subunit 7 in dog liver. Immunohistochemical examination showed that transferases immunoreacted with anti-GST 7-7 antibody have diffusely distributed throughout the lobule, while enzymes related to subunit 3 have been localized in a narrow range of cells around the central vein. These data suggest that GSTs immunologically associated with rat transferase subunit 7 may be major forms in dog liver.

Animals↗

PubMed1988

Accumulation of a globo-series glycolipid having Gal alpha 1-3Gal in PC12h pheochromocytoma cells.

In a previous paper, we reported the presence of globoside as a major neutral glycolipid in PC12 pheochromocytoma cells [Ariga, T., Macala, L. J., Saito, M., Margolis, R. K., Greene, L. A., Margolis, R. U., & Yu, R. K. (1988) Biochemistry 27, 52-58]. Recently, we found that subcloned PC12h cells accumulated another unusual neutral glycolipid. In order to characterize this glycolipid, PC12h cells were subcutaneously transplanted into rats. The induced tumor tissue accumulated two major neutral glycolipids, which were purified by Iatrobeads column and preparative thin-layer chromatographies. One of the glycolipids was found to be globoside, and the other had a globotriaosyl structure with an additional terminal Gal alpha 1-3 residue. Its structure was determined by fast atom bombardment mass spectrometry, two-dimensional proton nuclear magnetic resonance spectrometry (2D NMR), permethylation study, sequential degradation with exoglycosidase, and mild acid hydrolysis to be Gal(alpha 1-3)Gal(alpha 1-4)Gal(beta 1-4)Glc(beta 1-1')Cer.

Adrenal Gland Neoplasms↗

PubMed1988

A monoclonal antibody that recognizes a cluster of a disaccharide, NeuAc alpha(2----6)GalNAc, in mucin-type glycoproteins.

The structure of an epitopic carbohydrate recognized by a monoclonal antibody, MLS 102, was determined. A disaccharide, NeuAc alpha (2----6)GalNAc, the major prosthetic group of ovine submaxillary mucin (OSM) and related synthetic glycosides, NeuAc alpha(2----6)GalNAc alpha----Ser, NeuAc alpha(2----6)GalNAc beta----Ser, and NeuAc alpha (2----6)GalNAc beta----propyl, reacted with MLS 102 to similar extents, but the reaction was considerably weaker compared to that of OSM. This difference in reactivity could be ascribed to the occurrence of a cluster of the disaccharide on OSM. Purification of MLS 102-reactive antigens from a Triton X-100 extract of LS 180 cells by means of immunoaffinity chromatography gave mucin fractions (cMLS 102 antigen) with an OSM-like domain. Correlation between the content of the disaccharide, NeuAc alpha(2----6)GalNAc, in mucins and their reactivity with MLS 102 was observed.

Antigen-Antibody Complex↗

PubMed1988

Determination of adenosine in fetal perfusates of human placental cotyledons using fluorescence derivatization and reversed-phase high-performance liquid chromatography.

A simple, sensitive HPLC method using fluorescence detection was developed for determination of adenosine in fetal venous perfusates of dual-perfused cotyledons from human term placentas. Maternal and fetal circuits of in vitro placental cotyledons were perfused with physiological salt solution containing dextrose and dextran (Earle's medium). Conditions were established for optimal formation of fluorescent 1,N6-ethenoadenosine from adenosine and chloroacetaldehyde in Earle's medium and for optimal resolution of 1,N6-ethenoadenosine by reversed-phase HPLC of the reaction mixture. The yield of 1,N6-ethenoadenosine was enhanced by dilution and acidification of the sample matrix. Perfusate samples in autosampler vials were diluted 40% with water and reacted with chloroacetaldehyde for 40 min at 100 degrees C; replicate 100-microliters injections were made automatically from each reaction mixture for HPLC analysis with fluorescence detection on a column packed with 3 microns octadecylsilica (Hypersil). Calibration curves were prepared similarly from 4-100 nM adenosine in Earle's medium. Alternatively, perfusate samples were diluted twofold with dilute phosphoric acid to give a final pH of 5.4 before reaction with chloroacetaldehyde, and replicate 50-microliters injections were made automatically for HPLC; calibration curves were prepared from 2-400 nM adenosine in Earle's medium. 1,N6-Ethenoadenosine was well resolved from Earle's-derived artifactual peaks on chromatography with either a linear or a concave gradient of methanol in ammonium phosphate buffer. Total run times were 15 and 19 min, respectively. Sensitivity of measurement of adenosine was 2-4 nM. Derivatization of adenosine using the acidified reaction mixture gave a limit of detection of 100 fmol of adenosine per injection. Application of the method to analysis of adenosine in fetal venous perfusates of eight dual-perfused cotyledons, each from a different placenta, gave a range of 3.5-52 nM adenosine. Ischemia, imposed by cessation of maternal perfusion, caused a two- to sixfold increase in fetal venous perfusate adenosine concomitant with an increase in fetoplacental perfusion pressure; perfusion pressure and perfusate adenosine returned to baseline levels on reperfusion of the maternal circuit. This facile method of determination of perfusate adenosine should allow investigation of the role of placental adenosine release in regulation of fetoplacental vascular resistance and should be applicable to study of adenosine released by other isolated perfused organs.

Acetaldehyde↗

PubMed1988

Drug interactions between imipramine and benzodiazepines in rats.

The concomitant administration of diazepam and imipramine hydrochloride increased desipramine concentration in rat plasma, but decreased 2-hydroxyimipramine and 2-hydroxydesipramine concentrations; the concomitant administration of oxazepam and imipramine hydrochloride decreased imipramine, 2-hydroxyimipramine, and 2-hydroxydesipramine concentrations. Imipramine plasma protein binding was unaltered in all cases. Liver concentrations of imipramine and 2-hydroxydesipramine were increased by concomitant administration of oxazepam and imipramine hydrochloride. Concomitant administration of benzodiazepines and imipramine hydrochloride increased imipramine concentration in the brain. The effects of imipramine hydrochloride on hypothermia induced by reserpine, and on behavioral despair in rats was also studied. The concomitant administration of diazepam and imipramine hydrochloride led to a decrease in the anti-reserpine effect of imipramine hydrochloride and in the imipramine hydrochloride-induced recovery from immobility in the forced swimming test. These results are in accord with the findings on brain concentrations of imipramine and its metabolites.

Animals↗