TY - JOUR
T1 - FMLP actions and its binding sites in isolated human coronary arteries
AU - Keitoku, Mitsumasa
AU - Kohzuki, Masahiro
AU - Katoh, Hiroshi
AU - Funakoshi, Masayuki
AU - Suzuki, Shu
AU - Takeuchi, Masaharu
AU - Karibe, Akihiko
AU - Horiguchi, Satoru
AU - Watanabe, Jun
AU - Satoh, Shoichi
AU - Nose, Masato
AU - Abe, Keishi
AU - Okayama, Hiroshi
AU - Shirato, Kunio
PY - 1997/3
Y1 - 1997/3
N2 - The chemoattractant f-Met-Leu-Phe (FMLP) can modulate human coronary arterial tone without the involvement of peripheral leukocytes. We investigated the actions of FMLP and its cellular mechanism in human coronary arteries isolated 2-3 h after death. A single dose of FMLP (0.01-10 μM) produced transient contraction (or, followed by relaxation) responses in most human coronary rings examined. These responses to FMLP were in large part mediated by the generation of cyclooxygenase products, mainly thromboxane A2 (TXA2) and prostaglandin I2 (PGI2). Radiolabeled N-formyl hexapeptide, 125I-f-Nle-Leu-Phe-Nle-Tyr-Lys bound densely to intimal and adventitial sites that accumulated macrophages (CD68-positive) with a K(d) of 14-29 nM and, further, weakly to the media with a K(d) of 2.4-3.6 μM. Several cell types including macrophages, endothelial cells and smooth muscle cells were positively immunostained for both TXA2 synthase and PGI2 synthase. However, there was no significant relation between the magnitude of the responses to FMLP and dense macrophage accumulation in the intimal plaques or the adventitia. A reverse transcription-polymerase chain reaction showed predominant expression of FMLP receptor homologues, FPRH1 and FPRH2 mRNA, in human coronary medial tissues relative to that in leukocytes. In conclusion, FMLP produced transient tension changes in human coronary arteries, mainly via the generation of TXA2 and PGI2. This effect of FMLP did not appear to be mediated by the activation of densely accumulated intimal and/or adventitial macrophages, but by the activation of unidentified medial tissue cells which might have functional FMLP receptor homologues.
AB - The chemoattractant f-Met-Leu-Phe (FMLP) can modulate human coronary arterial tone without the involvement of peripheral leukocytes. We investigated the actions of FMLP and its cellular mechanism in human coronary arteries isolated 2-3 h after death. A single dose of FMLP (0.01-10 μM) produced transient contraction (or, followed by relaxation) responses in most human coronary rings examined. These responses to FMLP were in large part mediated by the generation of cyclooxygenase products, mainly thromboxane A2 (TXA2) and prostaglandin I2 (PGI2). Radiolabeled N-formyl hexapeptide, 125I-f-Nle-Leu-Phe-Nle-Tyr-Lys bound densely to intimal and adventitial sites that accumulated macrophages (CD68-positive) with a K(d) of 14-29 nM and, further, weakly to the media with a K(d) of 2.4-3.6 μM. Several cell types including macrophages, endothelial cells and smooth muscle cells were positively immunostained for both TXA2 synthase and PGI2 synthase. However, there was no significant relation between the magnitude of the responses to FMLP and dense macrophage accumulation in the intimal plaques or the adventitia. A reverse transcription-polymerase chain reaction showed predominant expression of FMLP receptor homologues, FPRH1 and FPRH2 mRNA, in human coronary medial tissues relative to that in leukocytes. In conclusion, FMLP produced transient tension changes in human coronary arteries, mainly via the generation of TXA2 and PGI2. This effect of FMLP did not appear to be mediated by the activation of densely accumulated intimal and/or adventitial macrophages, but by the activation of unidentified medial tissue cells which might have functional FMLP receptor homologues.
KW - Atherosclerosis
KW - Chemoattractants
KW - Coronary vasospasm
KW - Macrophages
KW - Prostaglandin
KW - Thromboxane
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UR - http://www.scopus.com/inward/citedby.url?scp=0031105012&partnerID=8YFLogxK
U2 - 10.1006/jmcc.1996.0291
DO - 10.1006/jmcc.1996.0291
M3 - Article
C2 - 9152849
AN - SCOPUS:0031105012
VL - 29
SP - 881
EP - 894
JO - Journal of Molecular and Cellular Cardiology
JF - Journal of Molecular and Cellular Cardiology
SN - 0022-2828
IS - 3
ER -