Reduced expressions of inducible nitric oxide synthase and cyclooxygenase-2 in vascular smooth muscle cells of stroke-prone spontaneously hypertensive rats

• Published in: Life sciences (1973) 2002-01, Vol.70 (8), p.917-926
• Main Authors: Hirafuji, Masahiko, Tsunoda, Marito, Machida, Takuji, Hamaue, Naoya, Endo, Toru, Miyamoto, Atsushi, Minami, Masaru
• Format: Article
• Language: English
• Subjects: Animals; Blotting, Western; Cells, Cultured; Cyclooxygenase; Cyclooxygenase 2; DNA Primers - chemistry; Down-Regulation; Epoprostenol - metabolism; Hypertension - enzymology; Inducible nitric oxide synthase; Interleukin-1 - pharmacology; Isoenzymes - genetics; Isoenzymes - metabolism; Muscle, Smooth, Vascular - drug effects; Muscle, Smooth, Vascular - enzymology; Nitrates - metabolism; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase - genetics; Nitric Oxide Synthase - metabolism; Nitric Oxide Synthase Type II; Nitrites - metabolism; Oxidative Stress; Prostaglandin I 2; Prostaglandin-Endoperoxide Synthases - genetics; Prostaglandin-Endoperoxide Synthases - metabolism; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger - metabolism; Vascular smooth muscle cells, stroke-prone spontaneously hypertensive rats
• ISSN: 0024-3205; 1879-0631
• DOI: 10.1016/S0024-3205(01)01464-3

Inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2 are expressed in vascular smooth muscle cells stimulated with interleukin-1β (IL-1β), resulting in the production of nitric oxide (NO) and prostaglandins (PGs) such as PGI 2. The iNOS and COX-2 proteins and their mRNA expressions in cultured vascular smooth muscle cells isolated from 6–7 week-old stroke-prone spontaneously hypertensive rats (SHRSP) were compared with those in the cells isolated from age-matched normotensive Wistar Kyoto rats (WKY). The IL-1β-induced NO production and iNOS expression in vascular smooth muscle cells of SHRSP were significantly lower than those in cells of WKY. Similarly, PGI 2 production and COX-2 expression were significantly lower in vascular smooth muscle cells of SHRSP than WKY, whereas there was no difference in the COX-1 expression. There were no significant differences in iNOS and COX-2 mRNA expressions between the two strains, suggesting that these protein expression may be reduced at the post-transcriptional level in cells of SHRSP. These results further suggest that the reduction of iNOS and COX-2 expressions in vascular smooth muscle cells may have relevance to the pathophysiology in SHRSP.