Functional Changes in Aqp4 Gene Expression in the Rat Hypothalamus under Different Drinking Regimens and Arterial Hypertension.

Aquaporin-4 (AQP4) is the main water channel in the central nervous system. AQP4 is highly expressed in brain structures, suggesting its crucial role in water transport in norm and in pathology. Here, we studied the effect of a change in the drinking regimen (water deprivation, hyperhydration) and inherited arterial hypertension on the expression of the AQP4 water channel gene in the hypothalamus, a regulatory brain center of visceral functions. The expression level of the Aqp4 gene in hyperhydrated animals was found to be more than 1.5 times lower than in water-deprived animals, which may reflect the need to prevent cytotoxic edema during increased fluid intake. Rats with inherited stress-induced arterial hypertension are characterized by an increased level of the Aqp4 gene in the hypothalamus, suggesting the involvement of this channel in processes associated with the regulation of brain water balance and the prevention of vasogenic cerebral edema in arterial hypertension. Thus, the presence of the AQP4 water channel in the brain, associated with the protection of brain cells, is functionally determined by the state of the body, as evidenced by bidirectional changes in Aqp4 expression during hyperhydration and arterial hypertension. [ABSTRACT FROM AUTHOR]