Antisense oligonucleotides against cytochrome P450 2C8 attenuate EDHF-mediated Ca(2+) changes and dilation in isolated resistance arteries.
Using a novel vessel culture technique in combination with antisense oligonucleotide transfection, we tested whether the endothelium-derived hyperpolarizing factor (EDHF) is a cytochrome P450 (CYP)-related compound. Isolated resistance arteries from hamster gracilis muscle (n=19) were perfused and exposed to antisense (As), sense (S), or scrambled (Scr) oligonucleotides against the coding region of CYP2C8/9, an isoform expressed in endothelial cells. Thereafter, NO- and prostaglandin-independent, EDHF-mediated vascular responses associated with hyperpolarization [i.e., decrease in smooth muscle calcium (Fura 2) and vasodilation] were studied after the application of acetylcholine (ACh). These EDHF-mediated responses were markedly attenuated (by 70%) by As- but not by S- or Scr-oligonucleotide treatment. However, the responses to norepinephrine (0.3 micromol/l), the NO donor sodium nitroprusside (1 micromol/l), and the K(Ca) channel activator NS1619 (100 micromol/l) were unaltered. As treatment, which specifically targeted the endothelial layer (as assessed by confocal microscopy), had no inhibitory effect on increases in endothelial calcium to ACh. It is concluded that a CYP2C8/9-related isoform functions as an EDHF synthase in hamster resistance arteries and that a product of this enzyme is an EDHF, or at least an integral part of the signaling cascade leading to EDHF-mediated responses.-Bolz, S.-S., Fisslthaler, B., Pieperhoff, S., de Wit, C., Fleming, I., Busse, R., Pohl, U. Antisense oligonucleotides against cytochrome P450 2C8 attenuate EDHF-mediated Ca(2+) changes and dilation in isolated resistance arteries.
Bolz
S S
SS
Physiologisches Institut, Ludwig Maximilians Universität, München, Germany. bolz@lrz.uni-muenchen.de
Fisslthaler
B
B
Pieperhoff
S
S
De Wit
C
C
Fleming
I
I
Busse
R
R
Pohl
U
U
D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001011:Aorta / Q000378:metabolism; D001158:Arteries / Q000187:drug effects / Q000502:physiology*; D001189:Aryl Hydrocarbon Hydroxylases; D001685:Biological Factors / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D006224:Cricetinae; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D008647:Mesocricetus; D018482:Muscle, Skeletal / Q000098:blood supply; D016376:Oligonucleotides, Antisense; D009924:Organ Culture Techniques; D039181:Steroid 16-alpha-Hydroxylase; D013250:Steroid Hydroxylases / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology*; D014664:Vasodilation / Q000502:physiology*
D001685:Biological Factors; D016376:Oligonucleotides, Antisense; C067410:endothelium-dependent hyperpolarization factor; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; D001189:Aryl Hydrocarbon Hydroxylases; D039181:Steroid 16-alpha-Hydroxylase; D000109:Acetylcholine; D002118:Calcium