BACKGROUND : Studies in animal models, in which internal hydrocephalus has been induced by obstructing the
cerebrospinal fluid pathways, have documented an up-regulation of the concentrations of aquaporin-4 (AQP4) in the
brain. In this study, the concentrations of aquaporin-1 (AQP1), AQP1, AQP4 and interleukin-6 (IL-6) were determined
in the CSF of dogs with idiopathic communicating hydrocephalus before and after the reduction of intraventricular
volume following ventriculo-peritoneal shunt (VP-shunt) treatment.
RESULTS : The concentrations of AQP4 and IL-6 were increased in the cerebrospinal fluid of dogs with hydrocephalus
compared to controls. Both parameters significantly decreased after surgical treatment, accompanied by decrease of
ventricular size and the clinical recovery of the dogs. AQP1 was not detectable in CSF.
CONCLUSIONS : Brain AQP4 up-regulation might be a compensatory response in dogs with hydrocephalus. Future
determination of AQP4 at the mRNA and protein level in brain tissue is warranted to substantiate this hypothesis.