Red blood cells: reservoirs of cis- and trans-epoxyeicosatrienoic acids.
Epoxyeicosatrienoic acids (EETs) are candidate endothelium-derived hyperpolarizing factors that demonstrate a wide range of biological effects. The presence of both cis- and trans-EETs in rat plasma was identified with HPLC-electrospray ionization tandem mass spectrometry in this study. The total EETs in plasma are 38.2 ng/ml with cis-EETs representing 21.4 +/- 0.4 ng/ml and trans-EETs 16.8 +/- 0.4 ng/ml. EETs in RBCs were estimated to be 20.2 ng/10(9) RBCs, which corresponds to 200 ng in RBCs contained in 1 ml blood. RBC incubation with 10 mM tert-butyl hydroperoxide resulted in 4.4-fold increase of total cis-EETs (from 9.2 to 40.2 ng/10(9) RBCs) and 5.5-fold increase of total trans-EETs (from 11.0 to 60.8 ng/10(9) RBCs). EETs were released (2 ng/ml) from RBCs after incubation at 37 degrees C for 10 min even after being washed 3 times, indicating that RBCs are reservoirs of plasma EETs. The identification of cis- and trans-EETs in RBCs and in plasma as well as their release from RBCs suggest a vasoregulatory role of RBCs in view of their potent vasoactivity.
Jiang
Houli
H
Department of Pharmacology, New York Medical College, Valhalla, NY 10595, USA. houli_jiang@nymc.edu
Quilley
John
J
Reddy
L Manmohan
LM
Falck
John R
JR
Wong
Patrick Y K
PY
McGiff
John C
JC
D015126:8,11,14-Eicosatrienoic Acid / Q000031:analogs & derivatives* / Q000097:blood / Q000737:chemistry; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004912:Erythrocytes / Q000737:chemistry*; D015227:Lipid Peroxidation; D008297:Male; D010743:Phospholipids / Q000097:blood / Q000302:isolation & purification; D051381:Rats; D017207:Rats, Sprague-Dawley; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism
D010743:Phospholipids; C046783:11,12-epoxy-5,8,14-eicosatrienoic acid; D015126:8,11,14-Eicosatrienoic Acid