The effect of hepatic impairment on the aquaporin-4 in the paraventricular (PVN) and Supraoptic (SON) nuclei of rat hypothalamus

Cholestasis, as an abnormality in liver function, is associated with decreasing water intake and changes in vasopressin level. The Paraventricular (PVN) and Supraoptic (SON) nuclei are important for the control of body fluid homeostasis. This can be take place with water channels or aquaporins to regulate water flow. Aquaporin 4 isoforms effectively convey the water on the brain. Due to reduced water intake in cholestasis and the roles of SON and PVN nuclei, this study was designed to determine the changes in aquaporin 4.
In this experimental study, male Wistar rats weighing 200 to 250 g were randomly divided into three groups, including the control (no surgery), sham (surgery Stretch) and cholestatic that had closed their bile duct (model used to cirrhosis), respectively. Aquaporin 4 densities in all groups were examined by immunohistochemistry.
The results indicate a high density of aquaporins 4 in SON and PVN nuclei in sham and control samples, but the sampling density of aquaporin 4 decreased in cholestasis.
The results of this study showed decreasing density of aquaporin 4 in SON and PVN of hypothalamus, in the parts of the effective in water intake and sensitive to the osmolarity and toxicity, in cholestasis. Cholestasis may probably reduce the density of aquaporin 4 and the water intake by increasing or decreasing of related factors, such as endotoxins.