Comment in:

Hypertension. 1998 Dec;32(6):1104-5.

Vascular smooth muscle nitric oxide synthase anomalies in Dahl/Rapp salt-sensitive rats.

Nephrology Research and Training Center, Department of Medicine, University of Alabama at Birmingham, and Department of Veterans Affairs Medical Center, 35294-0007, USA.

Salt-sensitive hypertension in the Dahl/Rapp rat (S strain) is prevented by L-arginine. Based on the observations that dexamethasone prevented the antihypertensive effect of L-arginine in these animals and the suggestion that a locus in or near an inducible nitric oxide synthase (NOS) gene on chromosome 10 cosegregated with hypertension in some F2 crosses that utilized the S rat, the present study explored the hypothesis that the vascular smooth muscle isoform of inducible NOS (NOS2) was abnormal in S rats. Primary cultures of aortic smooth muscle cells from S rats demonstrated impaired inducible NO production, which improved with increased L-arginine in the medium. Sequence analysis identified a single T-->C transversion that produced an amino acid substitution (S714P) between the FAD and FMN binding sites and a restriction fragment length polymorphism. This restriction fragment length polymorphism was present only in S rats. The mutation of NOS2 and the role of this enzyme in the pathogenesis of salt-sensitive hypertension in the Dahl/Rapp rat require further investigation.

PMID: 9535415 [PubMed - indexed for MEDLINE]