Inactivation of endothelium-dependent relaxing factor by liposome-encapsulated or cell-free hemoglobin

K. Nakai; T. Ohta; S. Tokuyama; H. Akama; Y. Kawakami; N. Matsuda; E. Tuschida; Y. Nakazato; S. Sekiguchi

Inactivation of endothelium-dependent relaxing factor by liposome-encapsulated or cell-free hemoglobin

K. Nakai, T. Ohta, S. Tokuyama, H. Akama, Y. Kawakami, N. Matsuda, E. Tuschida, Y. Nakazato, S. Sekiguchi

Research output: Contribution to journal › Article › peer-review

Abstract

The inhibitory effects of cellular and acellular hemoglobin (Hb) solutions on endothelium-dependent vasorelaxation were investigated in rabbit aortic strips. The tissues were precontracted with phenylephrine, after which acetylcholine (ACh) was added to induce a steady-state relaxation. All Hb solutions cumulatively reversed ACh-induced relaxation; liposome-encapsulated Hb and washed human red cells as cellular Hb reached a maximal vasconstriction at 1 mg/ml, while 2,3-diphosphoglycerae depleted Hb and pyridoxylated Hb as acellular Hb reached a plateau at 10 μg/ml. On the other hand, increases in oxygen affinity by pyridoxylation had little effect on this. These findings suggest that the cellularity is a very important factor influencing EDRF inhibition, and that acellular Hbs are more potent vasoconstrictors than cellular Hbs by a factor of about one hundred.

Original language	English
Pages (from-to)	854-857
Number of pages	4
Journal	Japanese Journal of Artificial Organs
Volume	23
Issue number	3
Publication status	Published - 1994 Jan 1
Externally published	Yes

Keywords

EDRF
blood substitutes
hemoglobin
liposome
vasoconstriction

ASJC Scopus subject areas

Biophysics

Cite this

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title = "Inactivation of endothelium-dependent relaxing factor by liposome-encapsulated or cell-free hemoglobin",

abstract = "The inhibitory effects of cellular and acellular hemoglobin (Hb) solutions on endothelium-dependent vasorelaxation were investigated in rabbit aortic strips. The tissues were precontracted with phenylephrine, after which acetylcholine (ACh) was added to induce a steady-state relaxation. All Hb solutions cumulatively reversed ACh-induced relaxation; liposome-encapsulated Hb and washed human red cells as cellular Hb reached a maximal vasconstriction at 1 mg/ml, while 2,3-diphosphoglycerae depleted Hb and pyridoxylated Hb as acellular Hb reached a plateau at 10 μg/ml. On the other hand, increases in oxygen affinity by pyridoxylation had little effect on this. These findings suggest that the cellularity is a very important factor influencing EDRF inhibition, and that acellular Hbs are more potent vasoconstrictors than cellular Hbs by a factor of about one hundred.",

keywords = "EDRF, blood substitutes, hemoglobin, liposome, vasoconstriction",

author = "K. Nakai and T. Ohta and S. Tokuyama and H. Akama and Y. Kawakami and N. Matsuda and E. Tuschida and Y. Nakazato and S. Sekiguchi",

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T1 - Inactivation of endothelium-dependent relaxing factor by liposome-encapsulated or cell-free hemoglobin

AU - Nakai, K.

AU - Ohta, T.

AU - Tokuyama, S.

AU - Akama, H.

AU - Kawakami, Y.

AU - Matsuda, N.

AU - Tuschida, E.

AU - Nakazato, Y.

AU - Sekiguchi, S.

PY - 1994/1/1

Y1 - 1994/1/1

N2 - The inhibitory effects of cellular and acellular hemoglobin (Hb) solutions on endothelium-dependent vasorelaxation were investigated in rabbit aortic strips. The tissues were precontracted with phenylephrine, after which acetylcholine (ACh) was added to induce a steady-state relaxation. All Hb solutions cumulatively reversed ACh-induced relaxation; liposome-encapsulated Hb and washed human red cells as cellular Hb reached a maximal vasconstriction at 1 mg/ml, while 2,3-diphosphoglycerae depleted Hb and pyridoxylated Hb as acellular Hb reached a plateau at 10 μg/ml. On the other hand, increases in oxygen affinity by pyridoxylation had little effect on this. These findings suggest that the cellularity is a very important factor influencing EDRF inhibition, and that acellular Hbs are more potent vasoconstrictors than cellular Hbs by a factor of about one hundred.

AB - The inhibitory effects of cellular and acellular hemoglobin (Hb) solutions on endothelium-dependent vasorelaxation were investigated in rabbit aortic strips. The tissues were precontracted with phenylephrine, after which acetylcholine (ACh) was added to induce a steady-state relaxation. All Hb solutions cumulatively reversed ACh-induced relaxation; liposome-encapsulated Hb and washed human red cells as cellular Hb reached a maximal vasconstriction at 1 mg/ml, while 2,3-diphosphoglycerae depleted Hb and pyridoxylated Hb as acellular Hb reached a plateau at 10 μg/ml. On the other hand, increases in oxygen affinity by pyridoxylation had little effect on this. These findings suggest that the cellularity is a very important factor influencing EDRF inhibition, and that acellular Hbs are more potent vasoconstrictors than cellular Hbs by a factor of about one hundred.

KW - EDRF

KW - blood substitutes

KW - hemoglobin

KW - liposome

KW - vasoconstriction

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M3 - Article

AN - SCOPUS:0028361862

SN - 0300-0818

VL - 23

SP - 854

EP - 857

JO - Japanese Journal of Artificial Organs

JF - Japanese Journal of Artificial Organs

IS - 3

ER -

Inactivation of endothelium-dependent relaxing factor by liposome-encapsulated or cell-free hemoglobin

Abstract

Keywords

ASJC Scopus subject areas

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