Hypertension effects on p73 expression in the rat circumventricular organs and cerebrospinal fluid

It has been reported that spontaneously hypertensive rats (SHR) show ventricular dilation, changes in CSF proteins and variations in the circumventricular organs (CVO) such as: the subcommissural organ (SCO), the subfornical organ (SFO) and the area postrema (AP) which are located in the walls of the third and fourth ventricles. On the other hand, p73 proteins are present in cells of the central nervous system (CNS) such as circumventricular structures and the neuroepithelium which are altered in ventricular dilation. The purpose of the present work is to study the TAp73 isoform expression in the circumventricular organs (CVO) and their variations in ventricular dilatation and arterial hypertension. Brains and cerebrospinal fluid (CSF) from control Wistar-Kyoto rats (WKY) and SHR were used. The paraffin sections containing the CVO were immunohistochemically proc-essed with anti-TAp73 and by western blot, p73 bands in the CSF and circumventricular organ extract were also identified. The western blot study showed bands marked with p73 in the CSF and CVO, the p73 band expression was bigger in the SHR than in the WKY rats. We also found stronger markings in the SFO, SCO and AP of the hypertensive rats than in the WKY rats. It could be concluded that hypertension in the SHR produces altera-tions in the relationship between the p73 protein, circumventricular structures and CSF.

High Blood Pressure Effects on the Brain Barriers and Choroid Plexus Secretion

High blood pressure produces ventricular dilation, variations in circumventricular organs and changes in the cerebrospinal fluid compositions. On the other hand, chronic hypertension in spontaneously hypertensive rats can cause changes in the integrity of the brain barriers: blood-cerebrospinal fluid barrier and blood brain barrier. The permeability of the brain barriers can be studied by using transthyretin and S-100β. In the present work we study the integrity of the brain barrier and the choroid plexus function variations in arterial hypertension. Control rats and spontaneously hypertensive rats were used and the choroid plexus were processed by immunohistochemistry with anti-transthyretin and anti-vasopressin. Western blot was also performed in cerebrospinal fluid, serum and choroid plexus using anti-S-100β, anti-transthyretin. The accumulation of transthyretin immunoreactive was bigger in spontaneously hypertensive rats with respect to the control. Vasopressin was also higher in spontaneously hypertensive rats with respect to the control. Western blot showed that transthyretin tetramer was higher in the spontaneously hypertensive rats than in the control rats. The expression of transthyretin monomer was lower in hypertensive rats than the control in the cerebrospinal fluid, the transthyretin monomer reaction in the blood was stronger in hypertensive than in control rats. Western blot for the S-100 β showed an increase in blood and cerebrospinal fluid of hypertensive rats. The high blood pressure produces a disruption of the blood brain barrier and blood to cerebrospinal fluid barrier that allows extravasations from the cerebrospinal fluid to the blood and from the blood to the cerebrospinal fluid.