Inhibition by triptoquinone-A of LPS- and IL-1 beta-primed induction of NO synthase in rat thoracic aorta.
We investigated the effect of triptoquinone-A (TQA), an active principal of Triptergium wilfordii, on the induction of nitric oxide synthase (NOS) promoted by endotoxin (LPS) and interleukin-1 beta (IL-1 beta). Prophylactic application of TQA selectively prevented LPS-primed initiation of L-arginine (Arg)-induced relaxation, and cGMP formation of rat thoracic aorta, and LPS-stimulated nitrite production by cultured aortic smooth muscle cells, which appear to be mediated by NOS expressed by LPS in vascular smooth muscle. TQA also prevented IL-1 beta-triggered initiation of Arg-induced relaxation and nitrite accumulation. These results suggest that TQA prevents LPS-or IL-1 beta-promoted induction of NOS in vascular smooth muscle, thus inhibiting development of Arg-induced vasorelaxation.
Moritoki
H
H
Department of Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokushima, Japan.
Hisayama
T
T
Kida
K
K
Kondoh
W
W
Inoue
S
S
Takaishi
Y
Y
D000818:Animals; D001011:Aorta / Q000187:drug effects*; D001120:Arginine / Q000494:pharmacology*; D006152:Cyclic GMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D007375:Interleukin-1 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008297:Male; D008516:Medicine, Chinese Traditional; D019001:Nitric Oxide Synthase / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
D007375:Interleukin-1; D008070:Lipopolysaccharides; D001120:Arginine; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP