EXPRESSION OF BRAIN NITRIC-OXIDE SYNTHASE MESSENGER-RNA IN VARIOUS TISSUES AND CULTURED-CELLS OF RAT

Nitric oxide (NO) is produced from L-arginine by the catalytic action of NO synthase (NOS). To elucidate the expression of brain NOS mRNA by tissues other than brain, we extracted poly(A)+RNA from various rat tissues and cultured cells and performed Northern blot analysis using a subcloned polymerase chain reaction product as a probe. Northern blot analysis revealed a single band corresponding to the size of brain NOS mRNA (about 10.5 kb), which was expressed abundantly in cerebellum, moderately in cerebrum, stomach and adrenal gland, and minimally in atrium, aorta, kidney and ovary, but not in ventricle, lung, liver, intestine, spleen, pancreas or urinary bladder. Rat pituitary tumor cell line (GH3) also expressed brain NOS mRNA. These data suggest that brain NOS gene is constitutively and widely expressed throughout rat tissues.