Effects of mitral regurgitation on the reflex diuresis to pulmonary lymphatic obstruction in rabbits.
Increasing the extravascular fluid of the airways acutely by obstructing pulmonary lymph drainage causes a reflex diuresis mediated by neuronal nitric oxide synthase in the renal medulla. The authors examined this reflex in rabbits with a chronic increase in extravascular fluid of the airways resulting from surgically induced mitral regurgitation. Intact rabbits served as controls. Renal neuronal (nNOS) and endothelial (eNOS) nitric oxide synthase expressions were also examined. The reflex was absent in rabbits with mitral regurgitation. There were significant increases in medullary and cortical nNOS mRNA compared to controls. The observed changes in mRNA levels correlated with nNOS protein levels. eNOS mRNA was unaffected.
Hallam
K M
KM
Division of Cardiovascular Medicine, University of California, Davis, California 95616, USA.
Edirisinghe
I
I
Balasuriya
U B R
UB
Gunawardena
S
S
Bravo
E M
EM
Ravi
K
K
Kappagoda
C T
CT
D000402:Airway Obstruction / Q000503:physiopathology*; D000818:Animals; D004231:Diuresis / Q000502:physiology*; D015633:Extravascular Lung Water / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic; D007672:Kidney Cortex / Q000098:blood supply / Q000201:enzymology / Q000294:innervation; D007679:Kidney Medulla / Q000098:blood supply / Q000201:enzymology / Q000294:innervation; D008208:Lymphatic System / Q000503:physiopathology*; D008943:Mitral Valve / Q000503:physiopathology; D008944:Mitral Valve Insufficiency / Q000503:physiopathology*; D052248:Nitric Oxide Synthase Type I / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011817:Rabbits; D012018:Reflex / Q000502:physiology*; D012039:Regional Blood Flow / Q000502:physiology; D012084:Renin-Angiotensin System / Q000502:physiology
D012333:RNA, Messenger; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III