Does intraventricular administration of synthetic rat atrial natriuretic factor prevent brain water accumulation in rats subjected to a systemic hypoosmolar fluid load?
Central administration of atrial natriuretic factor prevents brain water accumulation and induces sodium loss in a rat model of hypoosmolar fluid load, suggesting a role in brain volume homeostasis and potential management of brain edema.
The intraventricular administration of 0.2 or 2 micrograms of synthetic rat atrial natriuretic factor (syn rANF), sequence 101-126 of the precursor, prevented the water accumulation elicited in rat brain by a systemic hypoosmolar fluid load and led to a statistically significant sodium loss from the nervous tissue, while the potassium content remained unaltered. Similar syn rANF administration to rats not treated with a hypoosmolar fluid load caused no significant change in the water, potassium, and sodium content of the hemispheres. In this experiment, a primary systemic action of centrally administered syn rANF with ensuing secondary changes in brain ion and water homeostasis seems unlikely, as the serum osmolality and sodium and potassium concentrations remained unaltered. Thus, a central influence of the intraventricularly administered hormone upon the water and ion balances of the nervous tissue can be hypothesized. The significant loss of sodium may reflect the primary role of volume regulation of the nervous tissue, i.e., the loss of extracellular osmols such as Na+ in response to a hypoosmolar environment. These data lend further support to the concept that a central neuroendocrine system regulates brain ion and volume homeostasis. The possible role of ANF in the management of brain edema should be considered.
Dóczi et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: