論文 - 塚田　孝祐

Roles of hemoglobin allostery in hypoxia-induced metabolic alterations in erythrocytes: simulation and its verification by metabolome analysis

Kinoshita A., Tsukada K., Soga T., Hishiki T., Ueno Y., Nakayama Y., Tomita M., Suematsu M.

Journal of Biological Chemistry 282 （ 14 ） 10731-10741 2007年

研究論文（学術雑誌）, 単著, 査読有り

Erythrocytes with T-state-stabilized hemoglobin as a therapeutic tool for postischemic liver dysfunction.

Suganuma K, Tsukada K, Kashiba M, Tsuneshige A, Furukawa T, Kubota T, Goda N, Kitajima M, Yonetani T, Suematsu M

Antioxidants & redox signaling （MARY ANN LIEBERT, INC）  8 （ 9-10 ） 1847-1855 - 55 2006年

研究論文（学術雑誌）, 単著,  ISSN  1523-0864

　概要を見る

This study aimed to examine if T-state stabilization of hemoglobin in erythrocytes could protect against postischemic organ injury. Human erythrocytes containing three different states of Hb allostery were prepared: control Hb (hRBC), CO-Hb that is stabilized under R-state with the 6-coodinated prosthetic heme (CO-hRBC), and alpha-NO-deoxyHb stabilized under T-state (alpha-NO-hRBC). To prepare alpha-NO-RBC, deoxygenated RBC was treated with FK409, a thiol-free NO donor, at its half molar concentration to that of Hb; this procedure resulted in the 5-coordinated NO binding on the alpha-subunit heme, as judged by electron spin resonance spectrometry. Rats were subject to 20 min systemic hemorrhage to maintain mean arterial pressure at 40 mm Hg, and reperfused with one of hRBCs. This protocol for ischemia, followed by 60 min reperfusion with physiological saline, caused modest metabolic acidosis and cholestasis. Administration of hRBC or CO-hRBC significantly attenuated cholestasis and improved acidosis. Rats treated with alpha-NO-hRBC exhibited greater recovery of metabolic acidosis and bile excretion than those treated with hRBC or CO-hRBC, displaying the best outcome of local oxygen utilization in hepatic lobules. Half-life time of alpha-NO-RBC administered in vivo was approximately 60 min. These results suggest that T-state Hb stabilization by NO serves as a stratagem to treat postischemic organ dysfunction.

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Carbon monoxide as a guardian against hepatobiliary dysfunction.

Suematsu M, Tsukada K, Tajima T, Yamamoto T, Ochiai D, Watanabe H, Yoshimura Y, Goda N

Alcoholism, clinical and experimental research （LIPPINCOTT WILLIAMS & WILKINS）  29 （ 11 ） 134S-139S - 139S 2005年

研究論文（学術雑誌）, 単著, 査読有り,  ISSN  0145-6008

　概要を見る

Carbon monoxide (CO) generated through the reaction of heme oxygenase (HO) has attracted great interest in regulation of hepatobiliary homeostasis. The gas generated by HO-2 in the hepatic parenchyma can modestly activate soluble guanylate cyclase (sGC) expressed in hepatic stellate cells in a paracrine manner and thereby constitutively relax sinusoids. Kupffer cells express HO-1, the inducible isozyme, even under normal unstimulated conditions and constitutes approximately 30% of the total HO activity in this organ. Upon exposure to a variety of stressors such as cytokines, endotoxin, hypoxia and oxidative stress, the liver induces HO-1 and overproduces CO. The stress-inducible CO has been shown to guarantee ample blood supply during detoxification of heme and thus to play a protective role in the liver. However, molecular mechanisms by which CO serves as a protectant for hepatocytes, the cells expressing little sGC, remain to be solved. Previous observation suggested that CO modulates intracellular calcium mobilization through inhibiting cytochrome P-450 activities and thereby maintain stroke volume of bile canalicular contraction in cultured hepatocytes. CO also stimulates mrp2-dependent excretion of bilirubin-IX alpha and helps heme catabolism. Although a direct molecular target responsible for the latter event remains unknown, such properties of CO could support xenobiotic metabolism through its actions on sinusoidal hemodynamics and hepatobiliary systems.

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Red blood cell velocity and oxygen tension measurement in cerebral microvessels by double-wavelength photoexcitation

Tsukada K., Sekizuka E., Oshio C., Tsujioka K., Minamitani H.

Journal of Applied Physiology 96 （ 4 ） 1561-8 2004年

研究論文（学術雑誌）, 共著, 査読有り

Development of catheter-type optical oxygen sensor and applications to bioinstrumentation.

Tsukada K, Sakai S, Hase K, Minamitani H

Biosensors & bioelectronics 18 （ 12 ） 1439-1445 - 45 2003年11月

研究論文（学術雑誌）, 共著, 査読有り,  ISSN  0956-5663

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Platelet adhesion and arteriolar dilation during photothrombosis -observation with rat closed cranial and spinal windows-

Ishikawa M., Sekizuka E., Oshio C., Sato S., Yamaguchi N., Terao S., Tsukada K., Minamitani H. and Kawase T.

Journal of Neurological Science 194 （ 1 ） 59-69 2002年

研究論文（学術雑誌）, 単著, 査読有り

Direct measurement of erythrocyte deformability in diabetes mellitus with a transparent microchannel capillary model and high-speed video camera system.

Tsukada K, Sekizuka E, Oshio C, Minamitani H

Microvascular research （ACADEMIC PRESS INC）  61 （ 3 ） 231 - 9 2001年05月

ISSN  0026-2862

　概要を見る

To measure erythrocyte deformability in vitro, we made transparent microchannels on a crystal substrate as a capillary model. We observed axisymmetrically deformed erythrocytes and defined a deformation index directly from individual flowing erythrocytes. By appropriate choice of channel width and erythrocyte velocity, we could observe erythrocytes deforming to a parachute-like shape similar to that occurring in capillaries. The flowing erythrocytes magnified 200-fold through microscopy were recorded with an image-intensified high-speed video camera system. The sensitivity of deformability measurement was confirmed by comparing the deformation index in healthy controls with erythrocytes whose membranes were hardened by glutaraldehyde. We confirmed that the crystal microchannel system is a valuable tool for erythrocyte deformability measurement. Microangiopathy is a characteristic complication of diabetes mellitus, A decrease in erythrocyte deformability may be part of the cause of this complication. In order to identify the difference in erythrocyte deformability between control and diabetic erythrocytes, we measured erythrocyte deformability using transparent crystal microchannels and a high-speed video camera system. The deformability of diabetic erythrocytes was indeed measurably lower than that of erythrocytes in healthy controls. This result suggests that impaired deformability in diabetic erythrocytes can cause altered viscosity and increase the shear stress on the microvessel wall. (C) 2001 Academic Press.

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Direct measurement of erythrocyte deformability in diabetes mellitus with transparent microchannel capillary model and high-speed video camera system

Tsukada K., Sekizuka E., Oshio C., Minamitani H.

Microvascular Research 61 （ 3 ） 231-239 2001年

研究論文（学術雑誌）, 単著

Image correlation method for measuring blood flow velocity in microcirculation: correlation 'window' simulation and in vivo image analysis

Tsukada K., Minamitani H., Sekizuka E., Oshio C.

Physiological Measurement 21 （ 4 ） 459-471 2000年

研究論文（学術雑誌）, 共著, 査読有り