Altered amino acid levels in brainstem regions of spontaneously hypertensive rats.

The contents of glutamate, gamma-aminobutyric acid (GABA), glycine, beta-alanine and taurine in brainstem regions responsible for blood pressure regulation, the rostral ventrolateral medulla (RVL), the nucleus tractus solitarii (NTS) and the caudal ventrolateral medulla (CVL) regions, were determined in spontaneously hypertensive rats (SHR) as compared with Wistar Kyoto rats. In SHR, the content of glutamate was increased in the RVL, NTS and CVL regions whereas GABA and beta-alanine contents were decreased in the RVL and all the regions studied, respectively. There was no difference between WKY and SHR in glycine and taurine contents in all the regions studied. These results provide evidence suggesting alterations of brainstem amino acid metabolism in SHR.