Centrally Produced Nitric Oxide And The Regulation Of Body Fluid And Blood Pressure Homeostases

• Published in: Clinical and experimental pharmacology & physiology Vol. 27; no. 5-6; pp. 450 - 459
• Main Authors: Kadekaro, Massako, Summy-Long, Joan Y
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Science Pty 01.05.2000
• Subjects: angiotensin II; Animals; Blood Pressure - drug effects; Blood Pressure - physiology; Body Fluids - drug effects; Body Fluids - physiology; Brain - drug effects; Brain - physiology; drinking; Drinking Behavior - drug effects; Drinking Behavior - physiology; Enzyme Inhibitors - pharmacology; Homeostasis - drug effects; Homeostasis - physiology; Humans; Hypothalamic Hormones - metabolism; NG-nitro-L-arginine methyl ester; NG-Nitroarginine Methyl Ester - pharmacology; Nitric Oxide - physiology; oxytocin; Oxytocin - metabolism; vasopressin; Vasopressins - metabolism; Water-Electrolyte Balance
• ISSN: 0305-1870; 1440-1681
• DOI: 10.1046/j.1440-1681.2000.03264.x

SUMMARY 1. Nitric oxide (NO) tonically inhibits the basal release of vasopressin and oxytocin into plasma. 2. Nitric oxide inhibition on vasopressin secretion is removed, while that on oxytocin is enhanced, during water deprivation, hypovolaemia, moderate osmotic stimulation and angiotensin (Ang)II. This results in a preferential release of vasopressin over oxytocin that promotes conservation of water. 3. Nitric oxide facilitates drinking behaviour stimulated by water deprivation, osmotic stimulation, haemorrhage and AngII. Together with the hormonal response, NO produces a positive water balance during reductions in intracellular and intravascular volumes. 4. Nitric oxide produced within the central nervous system maintains resting arterial blood pressure partially by attenuating the pressor actions of AngII and prostaglandins. 5. Central production of NO is enhanced during osmotic stimulation to counterbalance the salt‐induced pressor response. 6. Paradoxically, central production of NO is also enhanced during haemorrhage, presumably to maintain peripheral vasodilation and blood flow to vital organs.