Basic Research
Copyright ©2006 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Gastroenterol. Mar 7, 2006; 12(9): 1367-1372
Published online Mar 7, 2006. doi: 10.3748/wjg.v12.i9.1367
Altered blood-brain barrier permeability in rats with prehepatic portal hypertension turns to normal when portal pressure is lowered
Francisco Eizayaga, Camila Scorticati, Juan P Prestifilippo, Salvador Romay, Maria A Fernandez, José L Castro, Abraham Lemberg, Juan C Perazzo
Francisco Eizayaga, Camila Scorticati, Juan P Prestifilippo, Salvador Romay, Maria A Fernandez, Abraham Lemberg, Juan C Perazzo, Laboratory of Portal Hypertension, Department of Pathophysiology, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
José L Castro, Catedra de Farmacología, School of Pharmacy and Biochemistry, University of Buenos Aires, Buenos Aires, Argentina
Supported by Grant TB 56 from the University of Buenos Aires, Buenos Aires, Argentina
Correspondence to: Professor J C Perazzo, Laboratory of Portal Hypertension, School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956, C.P. 1113, Ciudad Autónoma de Buenos Aires, Republica Argentina. jperazzo@ffyb.uba.ar
Telephone: +54 -11-49648368 Fax: +54-11-49648274
Received: February 17, 2005
Revised: May 1, 2005
Accepted: October 10, 2005
Published online: March 7, 2006
Abstract

AIM: To study the blood-brain barrier integrity in prehepatic portal hypertensive rats induced by partial portal vein ligation, at 14 and 40 d after ligation when portal pressure is spontaneously normalized.

METHODS: Adult male Wistar rats were divided into four groups: Group I: Sham14d , sham operated; Group II: PH14d , portal vein stenosis; (both groups were used 14 days after surgery); Group III: Sham40d, Sham operated and Group IV: PH40d Portal vein stenosis (Groups II and IV used 40 d after surgery). Plasma ammonia, plasma and cerebrospinal fluid protein and liver enzymes concentrations were determined. Trypan and Evans blue dyes, systemically injected, were investigated in hippocampus to study blood-brain barrier integrity. Portal pressure was periodically recorded.

RESULTS: Forty days after stricture, portal pressure was normalized, plasma ammonia was moderately high, and both dyes were absent in central nervous system parenchyma. All other parameters were reestablished. When portal pressure was normalized and ammonia level was lowered, but not normal, the altered integrity of blood-brain barrier becomes reestablished.

CONCLUSION: The impairment of blood-brain barrier and subsequent normalization could be a mechanism involved in hepatic encephalopathy reversibility. Hemodynamic changes and ammonia could trigger blood-brain barrier alterations and its reestablishment.

Keywords: Blood-brain barrier; Rats; Prehepatic portal hypertension