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Biomedical subjects

K Hatake

Publications and source records attributed to K Hatake.

At least 163 records · Page 9Linked to original sources

Inhibitory effect of aclarubicin on endothelium-dependent relaxation of rat aorta.

The effects of aclarubicin on endothelium-dependent and -independent vasorelaxations were investigated in aortic strips from rats. Aclarubicin (5.9-23.6 microM) inhibited endothelium-dependent relaxation and the increment of the cyclic GMP level in aortic strips in response to acetylcholine but not the endothelium-independent relaxation and the increase of cyclic GMP level in response to sodium nitroprusside. Aclarubicin also inhibited endothelium-dependent relaxations in response to ATP and calcium ionophore A23187. These results suggest that aclarubicin can inhibit endothelium-dependent relaxation by acting somewhere distal to receptor stimulation in vascular endothelial cells.

Acetylcholine↗

Alcohol addiction of methamphetamine abusers in Japan.

Fifty-eight methamphetamine (MAMP) abusers were surveyed to demonstrate the types of nature of MAMP abuse. In-depth interviews using psychophysiological techniques assessed the subjects to be truthful or deceptive about their abuse histories. Research diagnostic criteria determined the subjects clinical symptoms. The results show that three factors characterize MAMP abuse: significant correlation was found between the years of abuse; the manifestation of somatic or mental disorders or both, and alcohol (Alc) addiction. MAMP abusers who were nondrinkers or light drinkers developed a tendency to dislike Alc after MAMP abuse, while there was no change in Alc consumption in heavy drinkers. The findings suggest that the combined abuse of MAMP and Alc aggravates somatic and mental disorders and that Alc plays an important role in the fatal effect of MAMP, especially from small doses. This provides support for the synergistic effects between MAMP and Alc. Coadministration of MAMP and Alc appears to produce long-acting and more complicated changes in the brain's neurotransmitter function.

Adult↗

Effect of age on contractile response to angiotensin II in rat aorta.

The effects of aging on contractile response to angiotensin II and tachyphylaxis to it were investigated using aortic strips from rats aged 1.5, 4 and 22 months. Whether the endothelium was present or not, the contractile response to angiotensin II was greater and tachyphylaxis to it was less in 1.5-month-old rats than in 4- and 22-month-old rats. The differences between 4- and 22-month-old rats were not significant. Removal of the endothelium enhanced angiotensin II-induced maximal contraction and depressed the tachyphylaxis, these endothelial effects being greater in 4- rather than in 1.5-month-old rats. When the contractile force of angiotensin II was adjusted to a similar level for 1.5- and 4-month-old rats, the endothelial effect on the tachyphylaxis was greater in the 4-month-old rats, but no significant difference was noted in the endothelial effect on the contractile force. These results suggest that during growth, the contractile response of rat aorta to angiotensin II decreases while the endothelial effect on it increases.

Acetylcholine↗

Possible involvement of kinins in cardiovascular changes after alcohol intake.

Japanese healthy male subjects were divided into two groups, i.e., a normal aldehyde dehydrogenase (ALDH) group with a low Km isozyme of ALDH for acetaldehyde, and a deficient group without it. After intake of 0.4 g/kg alcohol, the deficient group showed high levels of blood acetaldehyde, facial flushing including an increased pulse rate and a fall in diastolic blood pressure, while the normal group did not manifest these changes. In the deficient group, the total kininogen concentration gradually decreased after alcohol intake due to a reduction in low molecular weight kininogen, and plasma prekallikrein remained unchanged. The normal group showed no significant changes in any of these values after alcohol intake. In an in vitro study with pooled plasma, the low concentrations of urinary kallikrein caused a decrease in the low molecular weight kininogen only. These results suggest that kinins released by acetaldehyde-induced activation of glandular kallikreins are associated with the changes in cardiovascular symptoms in deficient group which display flushing after alcohol intake.

Acetaldehyde↗

Influence of the endothelium on vascular responses of aortae from endotoxic rats.

Intraperitoneal injection of endotoxin diminished the in-vitro contractile response of rat aorta to phenylephrine or clonidine, whether the intimal layer was disrupted or not. The relaxing responses to acetylcholine and sodium nitroprusside in aorta precontracted with 10(-6) M phenylephrine were similar between control and endotoxic groups. However, when the precontractile force following phenylephrine was adjusted to an equivalent level, the relaxing responses to acetylcholine and sodium nitroprusside were diminished in the endotoxic aorta compared with the controls. There was no significant difference between the two groups in the increase in cyclic GMP levels induced by acetylcholine or by sodium nitroprusside. These results suggest that aortae from endotoxic rats show decreased responsiveness to alpha-adrenoceptor stimulation not because of enhancement of the endothelium-derived relaxing factor but because of abnormality in the vascular smooth muscle which is not specific for subtypes of the alpha-adrenoceptor.

Acetylcholine↗

Effect of aging on endothelium-dependent vascular relaxation of isolated human basilar artery to thrombin and bradykinin.

Using strips of human basilar arteries mounted in organ chambers to record isometric tension, we investigated vascular reactivity to thrombin and bradykinin. Both agents produced endothelium-dependent relaxation of basilar artery strips precontracted with phenylephrine but had no effect on resting tension in strips with or without endothelium. The relaxations caused by thrombin were abolished by antithrombin III/heparin, hirudin, and MD805. Thrombin but not bradykinin caused complete tachyphylaxis toward a second exposure. Indomethacin did not inhibit the relaxations induced by thrombin or bradykinin, whereas bromophenacyl bromide and methylene blue did. Aging decreased the relaxation induced by thrombin but did not affect the concentration needed to reach 50% maximal relaxation, nor did it affect the maximal relaxation in response to bradykinin, calcium ionophore A23187, and sodium nitroprusside. Our results suggest that thrombin and bradykinin produce endothelium-dependent relaxations mediated by an endothelium-derived relaxing substance and that the relaxation caused by thrombin is mediated by a proteolytic action on endothelial cells. The decrease in relaxations in response to thrombin with increasing age might be due to a decrease in the number or sensitivity of thrombin receptors on endothelial cells.

Adolescent↗

[Coordinate regulation of immune and inflammatory responses by cytokines].

In response to antigenic stimulation, T cells and macrophages secrete a set of glycoproteins termed lymphokines and monokines such as IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, GM-CSF, G-CSF, IFN-alpha, IFN-gamma, TNF-alpha, and lymphotoxin. These glycoproteins mediate immune and inflammatory responses by regulating proliferation, differentiation and maturation of lymphocytes, hemopoietic cells and endothelial cells. Along with factors such as M-CSF, IL-7, LIF, IFN-beta and TGF-beta produced by stromal cells, all these molecules are collectively called cytokines. Most cytokines are pleiotropic and have multiple biological activities. Accordingly, regulatory network is formed between lymphoid cells, hemopoietic cells and endothelial cells. All or a part of this network can be activated in different ways by unique combinations of cytokines. IL-3, IL-4 and IL-5 produced by TH2 cells enhance whereas IFN-gamma produced by TH1 cells suppresses IgE mediated allergic response. Through production of a spectrum of cytokines, T cells and macrophages play a vital role in coordinating the function of different body compartments in immune and inflammatory responses. The activation of cytokines genes in T cells and macrophages is transient. Therefore, an inflammatory response that involves proliferation and maturation of hemopoietic progenitor cells may be restricted to the site of cytokine production. The inducible nature of the hemopoiesis associated with inflammatory response is in contrast to the constitutive, steady state hemopoiesis that occurs in the bone marrow microenvironment in the absence of immunological stimuli.

Animals↗

Inhibitory effect of ethanol on endothelium-dependent vascular responsiveness.

The effect of ethanol was studied on the endothelium-dependent vascular responses in isolated rat aortic strips. Ethanol depressed the endothelium-dependent relaxation induced by acetylcholine and ATP but not that induced by the calcium ionophore, A23187. Endothelium-independent relaxation in response to sodium nitroprusside, a soluble guanylate cyclase activator, was not depressed by ethanol. On the other hand, ethanol significantly enhanced the contractile response to clonidine, an alpha 2-adrenoceptor agonist, in endothelium-intact strips and depressed it in endothelium-denuded strips. These results suggest that ethanol can inhibit endothelium-dependent relaxation by acting on endothelial cells but not on smooth muscle cells, and can also suppress an inhibitory effect of the endothelium on alpha 2-adrenoceptor-mediated vasoconstriction.

Acetylcholine↗

Effect of aclarubicin on contractile response of rat aorta.

The effect of aclarubicin on vasocontractility was investigated using aortic strips isolated from rats. The aortic strips from rats injected i.p. with aclarubicin (4 mg/kg body weight per day for 5 consecutive days) showed diminished contractile responses to KCl and phenylephrine in comparison with the controls injected with 0.9% saline. In vitro preincubation of rat aorta with aclarubicin (20-80 micrograms/ml) attenuated the aortic contractile responses to KCl and phenylephrine compared with the control preincubated with 0.9% saline. These results suggest that aclarubicin reduces the contractility of vascular smooth muscle directly.

Aclarubicin↗

Desensitization of alpha-1 adrenergic receptor mediated smooth muscle contraction in aorta from endotoxic rats.

Desensitization of vascular smooth muscles in endotoxemia was studied using the aorta from intraperitoneally endotoxin-injected rats. The KCl- and phenylephrine-induced contractions were significantly decreased in the endotoxic aorta compared to the control. In the endotoxic aorta the phenylephrine-induced contracture showed a gradual tension decrease after reaching a plateau and was attenuated by prior exposure to high concentration of phenylephrine, while KCl produced a sustained contraction and it was not affected by prior exposure to phenylephrine. The phenylephrine- and KCl-induced contractures of the control aorta showed stable plateaus and were not affected by prior exposure to phenylephrine. Neither diminished contractile force nor in vitro desensitization of phenylephrine contracture of isolated aorta was prevented by pretreatment of endotoxic rats with an alpha-adrenergic antagonist, phentolamine. These findings suggest that the contractile response to phenylephrine is easily desensitized in the endotoxic aorta compared to the control and neither this in vitro desensitization nor the diminution of contractile force is caused by in vivo exposure of aorta to a high concentration of catecholamines during endotoxemia.

Animals↗

Vasocontractile action of daunorubicin.

Daunorubicin (35.5-142 mumol L-1) induced in rat aortic strips a contraction with slow onset and a gradual development of tension on which neither phentolamine nor bromophenacyl bromide pretreatment had an effect. The contraction was not altered by removal of the endothelium but it was suppressed in calcium-free solution or by preincubation with nifedipine. These results suggest that daunorubicin directly stimulates vascular smooth muscle and induces a contractile response which is mainly dependent upon extracellular calcium.

Animals↗

Preferential differentiation of inflammatory cells by recombinant human interleukins.

The effects of recombinant human interleukins (IL) on hematopoiesis were explored by using suspension cultures of mononuclear cells of human umbilical cord blood and bone marrow cells. The results showed that IL-5 induced the selective differentiation and proliferation of eosinophils. After 3 weeks in culture with IL-5, over 90% of nonadherent cells in both bone marrow cell and cord blood cell cultures became eosinophilic myelocytes. Culture of the same cells with IL-4 resulted in the selective growth of OKT-3+ lymphocytes. In suspension cultures of bone marrow cells and cord blood cells grown in the presence of IL-3, basophilic, eosinophilic, and neutrophilic myelocytes developed within 2 weeks. By 3 weeks, however, the majority of non-adherent cells became eosinophilic myelocytes. In contrast to mouse bone marrow cell cultures, neither IL-3 nor combination of IL-3 and IL-4 induced the differentiation of mast cells in human bone marrow or cord blood cell cultures.

Basophils↗

Recombinant and native human urinary colony-stimulating factor directly augments granulocytic and granulocyte-macrophage colony-stimulating factor production of human peripheral blood monocytes.

Colony-stimulating factor from human urine (CSF-HU) has been purified to a homogeneous protein, and its complementary DNA (cDNA) has been cloned. Recombinant CSF-HU was prepared from a serum-free medium conditioned by Chinese hamster ovary cells transfected with the cDNA and purified by the same method as that for the native protein. Purified CSF-HU stimulated human bone marrow cells to form macrophage colonies. It also stimulated human mature monocytes prepared from peripheral blood of healthy volunteers to produce human active colony-stimulating activity that stimulates human bone marrow cells to form granulocyte and macrophage colonies. This activity was partially neutralized by the addition of both polyclonal antibodies against human granulocyte colony-stimulating factor and against human granulocyte-macrophage CSF, respectively. The stimulation of monocytes by CSF-HU was not inhibited by the addition of polymyxin-B, which is known as a potent inhibitor of endotoxin. On the other hand, CSF-HU did not stimulate monocyte production of interleukin-1 and interferon. These results indicate that recombinant and native CSF-HU stimulates immature cells as well as mature cells in the human monocyte lineage.

Cell Differentiation↗

Role of calcium in the potentiating effect of phorbol ester on KCl-induced vasocontraction.

The mechanism of the potentiating effect of phorbol ester on potassium-induced contraction in rat aorta was investigated. The contractile response to KCl in the medium containing 0.5 mM CaCl2 was significantly increased by pretreatment with 10(-8) M phorbol 12-myristate 13-acetate (PMA), but not with 10(-7) M 4 alpha-phorbol. The dose-response curve to calcium in 30 mM KCl-induced contraction was shifted to the left by PMA pretreatment and the EC50 value (the concentration producing a half maximal response) of calcium was significantly lower in aorta pretreated with PMA than in the control. On the other hand, calcium influx stimulated by 30 mM KCl was not changed by PMA pretreatment. Both the contractile response and the corresponding calcium influx induced by 30 mM KCl were abolished by preincubation with 10(-6) M verapamil for 45 min. These results suggest that activation of protein kinase C potentiates the contractile response to KCl by increasing the sensitivity of the intracellular contractile apparatus for calcium.

Animals↗

Effect of phorbol ester on contractile response of aorta from endotoxic rats.

The influence of phorbol ester on the isometric contractile response of aorta from endotoxic rats was examined. In endotoxic rat aorta, the contractile responses to KCl and phorbol 12,13-dibutyrate (PDBu) were both remarkably diminished, compared to those in control rat aorta. Preincubation with PDBu augmented the aortic contractile response to KCl in both control and endotoxic rats. This augmentative effect of PDBu was significantly more pronounced in endotoxic rats than in controls. When the contractile response to 80 mM KCl reached a plateau after PDBu pretreatment, addition of 5 mM CaCl2 (final concentration) to the organ bath completely reversed the diminished contractile response of endotoxic rat aorta to the control level. These results suggest that the hyporesponsiveness of endotoxic rat aorta to KCl may be caused by decreases in both protein kinase C mediated response and calcium sensitivity of vascular smooth muscle cells.

Animals↗

Selective differentiation and proliferation of hematopoietic cells induced by recombinant human interleukins.

Effects of recombinant human interleukins on hematopoiesis were explored by using suspension cultures of mononuclear cells of human umbilical-cord blood and bone marrow. The results showed that interleukin 5 induced the selective differentiation and proliferation of eosinophils. After 3 weeks in culture with interleukin 5, essentially all nonadherent cells in both bone marrow and cord blood cell cultures became eosinophilic myelocytes. Culture of the same cells with interleukin 4 resulted in the selective growth of OKT3+ lymphocytes. However, OKT3+ cells did not develop if the bone marrow cells were depleted of OKT3+/OKT11+ cells prior to the culture, indicating that interleukin 4 induced the proliferation of a subpopulation of resting T cells present in cord blood and bone marrow cell preparations. In suspension cultures of bone marrow cells and cord blood cells grown in the presence of interleukin 3, basophilic, eosinophilic, and neutrophilic myelocytes and macrophages developed within 2 weeks. By 3 weeks, however, the majority of nonadherent cells became eosinophilic myelocytes. In contrast to mouse bone marrow cell cultures, neither interleukin 3 nor a combination of interleukins 3 and 4 induced the differentiation of mast cells in human bone marrow or cord blood cell cultures.

Bone Marrow Cells↗