Early Postnatal Glutamate Treatment Results in Altered Vascular Responsiveness to Serotonin and Noradrenaline in Adult Rats.
OBJECTIVES: To evaluate possible alterations of vascular responsiveness to vasoactive hormones in the vessel preparations from adult rats treated neonatally with high doses of glutamate. METHODS: The responses to noradrenaline and serotonin in perfused hindlimb vascular bed and isolated renal artery were measured in MSG-treated (2 and 4 mg/g BW) and control groups of adult rats at the age of 10 weeks. Acetylcholine test was used to assess the endothelium-dependent relaxation of the hindlimb vascular preparation. The vessel specimens from this vascular bed were evaluated histologically. RESULTS: Vasoconstrictory responses to noradrenaline and serotonin were significantly reduced in the hindlimb vascular bed in MSG-treated rats. In the renal artery, a significant decrease of the responses to noradrenaline was found without significant changes in the responses to serotonin. The observed changes were more pronounced in groups treated with a high dose of MSG. Comparison of relaxing responses to acetylcholine in the hindlimb preparation did not show any statistically significant differences in control and MSG treated groups. Histological evaluation of this preparations did not reveal any endothelial damage or morphological changes of vessel wall. CONCLUSIONS: The obtained results showed reduced vascular responsiveness to vasoconstrictory agents in adult rats neonatally treated with MSG suggesting that early postnatal administration of glutamate may result in irreversible changes in cardiovascular function.
Kristova
V
Department of Pharmacology, Faculty of Medicine, Comenius University, 81108 Bratislava Slovakia.
Kriska
M
Babal
P
Jezova
D