A scanning electron microscopic study on the architecture of lymph vessels and intranodal lymph pathways of lymph nodes in pigs.
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Animals↗
Biomedical subjects
H Kitagawa
Publications and source records attributed to H Kitagawa.
Blood supply and microvasculature of the lymph nodes in pigs.
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Animals↗
Light and electron microscopic studies on chicken intestinal globule leucocytes.
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Animals↗
Ca2+ influx mediated through the GPIIb/IIIa complex during platelet activation.
When aequorin-loaded platelets were stimulated with thrombin, the luminescence signal of aequorin showed two peaks. From experiments with 1 mM external Ca2+ or EGTA, both one-half of the first peak and the entire second peak reflected the influx of Ca2+ from the external medium, and the remaining half of the first peak reflected the mobilization of Ca2+ from its storage site. A monoclonal antibody (TM83) that recognizes the glycoprotein IIb/IIIa (GPIIb/IIIa) complex which has binding sites for fibrinogen and the synthetic peptide GRGDSP are known to inhibit fibrinogen binding and platelet aggregation. Both eliminated the second peak of intracellular free calcium ([Ca2+]i). Similar effects were observed during activation by collagen, but not during PMA activation. It was concluded that the GPIIb/IIIa complex was intimately related to a part of the Ca2+ influx during the activation of platelets.
Aequorin↗
Characterization of tumor-associated fucogangliosides from PC 12 pheochromocytoma cells.
PC 12h pheochromocytoma cells were subcutaneously transplanted into rat. We found the transplanted tumors accumulated some fucogangliosides associated with PC 12 cells. These gangliosides were isolated and purified by DEAE-Sephadex A-25 and Iatrobeads column chromatographies. Their structures were determined by fast atom bombardment mass spectrometry, proton nuclear magnetic resonance spectrometry, permethylation study, and sequential degradation using various exoglycosidases and mild acid hydrolysis. Two tumor-associated fucogangliosides were found to possess the blood group B determinant as follows: G6: IV2Fuc alpha, IV3Gal alpha, II3NeuAc, GgOse4Cer; G11: IV2Fuc alpha, IV3Gal alpha, II3 (NeuAc)2, GgOse4Cer. A ganglioside with the similar structure as ganglioside G6 was isolated from rat hepatoma cells (Holmes, E.H., and Hakomori, S-I. (1982) J. Biol. Chem. 257, 7698-7703). However, ganglioside G11 has not previously been reported in the literature. These fucogangliosides reacted with the monoclonal antibody prepared by immunizing mice with PC 12h cells. Other fucogangliosides were also found to accumulate in the transplanted tumor tissues. They were identified as fucosyl-GM1 and fucosyl-GDlb. These fucogangliosides did not react with the monoclonal antibody against PC 12h cells.
Adrenal Gland Neoplasms↗
Immunoaffinity purification and characterization of nucleotide pyrophosphatase from human placenta.
Nucleotide pyrophosphatase [EC 3.6.1.9] was purified to homogeneity from human placenta using a monoclonal antibody affinity column. By sodium dodecylsulfate--polyacrylamide gel electrophoresis, the purified enzyme showed a major band at a molecular size of 130 K. The enzyme was a glycoprotein with N-linked oligosaccharides consisting of both complex- and oligomannoside-types. Substrate specificity to hydrolyze phosphodiester and phosphosulfate linkages as well as other properties were similar to those of nucleotide pyrophosphatase and phosphodiesterase from other sources.
Amino Acids↗
Mucin-carbohydrate directed monoclonal antibody.
To raise monoclonal antibodies recognizing cancer-associated alterations of the carbohydrate structure of glycoproteins, Balb/c mice were immunized with human colonic cancer cells (LS 180 from ATCC). One of the generated hybridomas produced a monoclonal antibody that bound to the carbohydrate moiety of mucin-type glycoproteins from LS 180. The antibody did not bind to glycoproteins from another colonic cancer cell line, SW 1116, or to glycolipids from any of the colonic cancer cell lines. The antibody bound to ovine and bovine submaxillary mucins (OSM and BSM). NeuAc alpha 2----6Ga1NAc seemed to be involved in the epitope.
Animals↗
Differing expression patterns and evolution of the rat kininogen gene family.
The present investigation using molecular cloning and sequence analysis concerns the examination of the molecular basis for different expression patterns of two types of the rat kininogen genes. We show that the low molecular weight and high molecular weight forms of K kininogens are produced from a single gene through alternative usage of two 3'-coding regions, whereas only the low molecular weight forms of T kininogens are generated as a result of several mutational changes in the high molecular weight-specifying regions of both T-I and T-II kininogen genes. The mutational changes include a nucleotide substitution at the polyadenylation/processing signal site, nucleotide deletions resulting in the frame-shift mutation, and an insertion of the type 2 Alu-equivalent sequence. Because kininogens represent a multifunctional protein comprising the proteinase-inhibitory activity, the kinin moiety, and the clotting activity, these results present evidence indicating the molecular basis for the disappearance of a part of the gene functions. We also show that the K and T kininogen genes as well as the two T kininogen genes are extremely homologous, excluding and including the above mutational changes, respectively. These structural relationships allow us to envisage evolutionary processes for the generation of the rat kininogen gene family, particularly for the disappearance of a part of the gene functions.
Animals↗
Tumor necrosis factor stimulates gelatinase and collagenase production by granulation tissue in culture.
Tumor necrosis factor (TNF, 2.6 X 10(-11)-10(-9) M) caused an increase in the production of active gelatinase and latent collagenase by granulation tissue in culture. As determined by SDS-substrate polyacrylamide gel electrophoresis, granulation tissue produced mainly two species of gelatinase with molecular weights of 64 kDa and 57 kDa, and an additional 80-kDa gelatinase was produced by TNF treatment. The results suggest that TNF may play a role in a rapid collagen turnover in the carrageenin-induced granulation tissue in rats.
Animals↗
Endothelium-dependent increases in rat gastric mucosal hemodynamics induced by acetylcholine and vagal stimulation.
The role of vascular endothelial cells in the vagal control of hemodynamics was studied in rat gastric mucosa. Vagal stimulation and intra-arterial administration of acetylcholine and of papaverine increased hemoglobin (Hb) and oxygen saturation of hemoglobin (SO2) in the gastric mucosa. The increases induced by vagal stimulation were reduced but not abolished by atropine. The responses to acetylcholine and vagal stimulation were reduced by quinacrine, p-bromophenacyl bromide and nordihydroguaiaretic acid, while indomethacin had no effect. Intra-arterial infusion of collagenase removed the endothelial cells from submucosal vasculatures and depressed the increase in mucosal hemodynamics in response to acetylcholine and vagal stimulation. The response to papaverine was not depressed in rats treated with quinacrine or collagenase. These results suggest that the increase in gastric mucosal blood flow induced by acetylcholine or vagal stimulation is mediated by the endothelium-derived relaxing factor.
Acetylcholine↗
Imipramine treatment alters the pharmacokinetics and pharmacodynamics of diazepam.
This report describes observations of the relationship between the pharmacokinetics and pharmacodynamics of diazepam (7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one ; 5 mg/kg) during the concomitant administration of diazepam and imipramine hydrochloride (5-[3-(dimethylamino)propyl]-10,11-dihydro-5H-dibenz[b,f]azepine monohydrochloride; 20 and 50 mg/kg) to rats. We measured plasma, brain, and liver concentrations of diazepam and its metabolites in rats by high-performance liquid chromatography. The concomitant use of imipramine hydrochloride increased diazepam and desmethyldiazepam concentrations, but decreased temazepam and oxazepam concentrations in rat plasma. Diazepam plasma protein binding was unaltered. The liver concentrations of diazepam and its metabolites showed similar changes in their plasma concentrations. The concomitant use of imipramine hydrochloride increased the concentrations of diazepam and its metabolites in the brain. We also studied the effect of benzodiazepines on convulsions induced by pentylenetetrazole (6,7,8,9-tetrahydro-5H-tetrazolo[1,5-a] azepine; 135 mg/kg) in rats. The concomitant use of imipramine hydrochloride led to an increased antipentylenetetrazole effect of diazepam. This result is in accordance with the findings on brain concentrations of diazepam and its metabolites.
Animals↗
Enhancement of contractile responses to partial alpha-adrenoceptor agonists during warming in rat aorta.
We examined the effects of warming on the contractile responses to full and partial alpha-adrenoceptor agonists in rat aorta. The contractions elicited by norepinephrine and methoxamine were not affected during warming (40 degrees C, 42 degrees C), whereas those induced by clonidine and St 587 were significantly enhanced. KCl-induced contractions of rat aorta were not affected by warming. The dissociation constants of clonidine and St 587 at 40 degrees C were not different from those at 37 degrees C. At 40 degrees C, the receptor occupancy-contractile response curve of clonidine was a hyperbolic curve similar to that of methoxamine at 37 degrees C, although at 37 degrees C the curve was almost linear. The responses of St 587 at both 37 degrees C and 40 degrees C were related inversely hyperbolic to the receptor occupancy, but the receptor occupancy-contractile response curve was shifted to the left and upward during warming. Clonidine and St 587 elicited equal responses at lower fractional occupancies at 40 degrees C than at 37 degrees C. The relative efficacies of clonidine and St 587 to methoxamine were significantly augmented during warming. It is suggested that the contractile responses to partial alpha-adrenoceptor agonists in rat aorta are enhanced during warming, and that this effect is related to the intrinsic efficacy of the agonists rather than to any function of their relative selectivity for alpha 1- or alpha 2-adrenoceptors. Such enhancement is due to augmentation of the efficacy rather than to augmentation of the affinity of the agonists.
Adrenergic alpha-Agonists↗
Localization of dehydropeptidase-I, an enzyme processing glutathione, in the rat kidney.
An antibody prepared against dehydropeptidase-I, one of the glutathione processing enzymes, from the renal membrane fraction of rats was employed to localize at the light microscopic level the enzyme in the kidney using the avidin/biotin-peroxidase complex method. Dehydropeptidase-I was found to be present on both the brush border and the basolateral membranes of proximal tubular cells. Furthermore, the enzyme activity in the isolated brush border and basolateral membrane fractions was also determined. Distribution profiles of the enzyme activity showed good agreement with the results of the immunohistochemical observations.
Animals↗
In vitro effect of cinnamic aldehyde, a main component of Cinnamomi Cortex, on human platelet aggregation and arachidonic acid metabolism.
The in vitro effect of cinnamic aldehyde, a main component of Cinnamomi Cortex, on platelet aggregation and arachidonic acid (AA) metabolism in human platelets was studied. Cinnamic aldehyde reduced platelet aggregation of both platelet rich plasma and washed platelets, dose-dependently. This compound also decreased the formation of the metabolites of AA such as thromboxane B2 (TXB2), 12-hydroxy heptadecatrienoic acid and 12-hydroxyeicosatetraenoic acid in collagen-stimulated washed platelets. The conversion of exogenous [14C]AA to cyclooxygenase metabolites or 12-lipoxygenase metabolite was not altered significantly by the addition of cinnamic aldehyde. On the other hand, collagen-induced release of [14C]AA and its metabolites from washed platelets prelabeled with [14C]AA was markedly reduced by the addition of cinnamic aldehyde. These results suggested that cinnamic aldehyde suppressed the release of AA from platelet membrane phospholipids and then reduced the formation of thromboxane A2. This inhibitory effect of cinnamic aldehyde on AA release and TXB2 formation may contribute to reduced platelet aggregation.
Acrolein↗
Anti-thrombotic and anti-atherogenic action of eicosapentaenoic acid.
Effects of dietary supplementation with highly purified EPA (1.8-2.7 g/day) for 16 weeks on platelet and red blood cell function and serum lipids concentration were investigated in patients with various thrombotic diseases. Decreases in platelet aggregation, thromboxane formation in platelets, platelet retention and whole blood viscosity, increased red blood cell deformation and prolongation of bleeding time were observed in the present study. In addition a reduction in serum cholesterol and triglyceride concentrations was noted in patients with hyperlipidemia after EPA ingestion. Some clinical improvements such as improvement of diabetic gangrene or peripheral vascular occlusive disease were observed. These results indicate that dietary supplementation of purified EPA may be beneficial for prevention and treatment of cerebro- and cardiovascular diseases.
Arteriosclerosis↗
[Drug interaction of imipramine hydrochloride to the pharmacodynamics and pharmacokinetics of oxazepam].
In this report, we studied drug interaction between oxazepam and imipramine in rats. Oxazepam (20 mg/kg) and imipramine (20 or 50 mg/kg) were administrated orally. The oxazepam concentration in plasma, brain and liver were measured by the method of HPLC. The concomitant use of imipramine induced extension of the elimination half life (T 1/2 beta) and an increase of the area under the concentration time-curve (AUC) on the plasma concentration of oxazepam. With the concomitant use of imipramine, the AUC of oxazepam brain concentration increased approximately 1.42 to 1.56 in contradistinction to oxazepam alone. The anti-pentylenetetrazol effect of oxazepam at 1 hr after administration was increased by the concomitant use of imipramine, but there were no combination effects at 4 hr. The motor incoordination effect of oxazepam and diazepam was measured by the rotarod method. Oxazepam has little effect on the motor incoordination as compared with diazepam. The plasma protein binding of oxazepam was not changed by the combined use of imipramine both in vitro and in vivo. The pharmacodynamic effects of oxazepam were increased by the concomitant use of imipramine, and these effects were in reasonably good agreement with the change in brain concentration of oxazepam.
Animals↗
Effects of co-administration of monomethylaminoantipyrine and cobaltous chloride on hepatic glutathione level and glutathione-related enzyme activities in rats.
Concurrent administration of monomethylaminoantipyrine (MAA) and CoCl2 caused a significant decrease of hepatic reduced glutathione and oxidized glutathione levels. Furthermore, the increase of glutathione S-transferase activity by combined treatment resulted in the decrease of Se-dependent glutathione peroxidase activity.
Aminopyrine↗
Suppression of pentylenetetrazol-induced seizures by hydralazine associated with 5-hydroxytryptaminergic system in rat brain.
The effects of hydralazine on the central nervous system were studied in rats. Administration of hydralazine (10 mg/kg, i.p.) transiently, but significantly suppressed the seizures elicited by pentylenetetrazol (PTZ). The suppressive actions were potentiated in the animals pretreated with either reserpine or p-chlorophenylalanine, but not alpha-methyltyrosine. Methysergide, an antagonist of 5-hydroxytryptamine (5-HT) receptors, could abolish the effect of hydralazine on the tonic component of the seizures, but unlikely that on the clonic one. Although 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) levels in the brain were both significantly increased after the administration of hydralazine, the increased levels of 5-HIAA reached the peak level earlier than those of 5-HT did. In 5-HT turnover, hydralazine did not change the 5-HT synthesis rate, but the drug inhibited the elimination of 5-HIAA from the brain. The accumulation of 5-HIAA after the inhibition of the acid transport system by probenecid was transiently, but significantly increased in the animals treated with hydralazine. The potency of the suppressive effects of hydralazine on PTZ-induced seizures was in parallel with the rate of 5-HIAA formation in the brain. These results suggest that hydralazine might antagonize the PTZ-induced seizures at least partly by modulating the activation in the central 5-HT-ergic system.
Animals↗