Influence of mannitol‐induced reduction in CSF Na on nervous and endocrine mechanisms involved in the control of fluid balance

摘要: Infusions (20 microliter/min) of isotonic (0.27 M) and hypertonic (0.7 mannitol dissolved in Na-free artificial CSF were made for 1 h. into the lateral cerebral ventricle (IVT) conscious water-replete sheep. The IVT infusion both 0.27 M 0.7 induced a water-diuresis. Samples collected prior to, 5, 35, 65, 125 min after end infusion. These consistently showed reduction [Na], while osmolality remained unchanged mannitol, was considerably increased mannitol. In 44 dehydrated sheep 6 water deprivation as such caused marked increase plasma [Na] osmolality. h further osmolality, decreased reached values below normal animals. also fall ADH resulting water-diuresis, extinguished thirst Furthermore, markedly reduced renal sodium excretion with causing any substantial change blood aldosterone, spite fact that there conspicuous renin concentration. study supports view sensitive receptors close to ventricular system participate regulation secretion, intake, release, excretion.