Central osmotic regulation of sympathetic nerve activity.
OBJECTIVE
In this review, we will focus on the central neural mechanisms that couple osmotic perturbations to changes in sympathetic nerve discharge, and the possible impact these actions have in cardiovascular diseases such as arterial hypertension and congestive heart failure.


RESULTS
Changes in extracellular fluid osmolality lead to specific regulatory responses in defence of body fluid and cardiovascular homeostasis. Systemic hyperosmolality is well known to stimulate thirst and the release of antidiuretic hormone. These responses are largely due to osmosensing neurones in the forebrain lamina terminalis and hypothalamus and are critical elements in a control system that operates to restore body fluid osmolality. An equally important, but less characterized, target of central osmoregulatory processes is the sympathetic nervous system.


CONCLUSIONS
Understanding the neurobiology of sympathetic responses to changes in osmolality has important implications for body fluid and cardiovascular physiology. By stabilizing osmolality, vascular volume is preserved and thereby relatively normal levels of cardiac output and arterial pressure are maintained.
Toney
G M
GM
Department of Physiology: MC 7756, The University of Texas Health Science Center, San Antonio, TX 78229-3900, USA.
Chen
Q H
QH
Cato
M J
MJ
Stocker
S D
SD
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D004285:Dogs; D005110:Extracellular Space / Q000502:physiology*; D006333:Heart Failure / Q000503:physiopathology; D006801:Humans; D006973:Hypertension / Q000503:physiopathology; D007424:Intracellular Fluid / Q000502:physiology; D007668:Kidney / Q000502:physiology; D009994:Osmolar Concentration; D016548:Prosencephalon / Q000502:physiology; D051381:Rats; D012965:Sodium Chloride / Q000378:metabolism; D013564:Sympathetic Nervous System / Q000502:physiology*; D014667:Vasopressins / Q000378:metabolism; D014882:Water-Electrolyte Balance / Q000502:physiology
D014667:Vasopressins; D012965:Sodium Chloride