Loss of tonic neuronal activity to release L-DOPA in the caudal ventrolateral medulla of spontaneously hypertensive rats.
Neurosci Lett
; 198(1): 37-40, 1995 Sep 22.
Article
en En
| MEDLINE
| ID: mdl-8570091
ABSTRACT
Experiments were designed to clarify whether a tonic L-DOPA system is altered in the caudal ventrolateral medulla (CVLM) of adult spontaneously hypertensive rats (SHR), compared to age-matched Wistar-Kyoto rats (WKY). By microdialysis in CVLM, basal L-DOPA release was constantly detectable and was lower in SHR than that in WKY. This release was reduced by tetrodotoxin perfusion (1 microM) in WKY to a basal level in SHR, whereas no modification occurred with tetrodotoxin in SHR. No difference of tyrosine hydroxylase and DOPA decarboxylase activities in the CVLM region was seen between the two strains. By microinjections into depressor sites of CVLM, L-DOPA (10-300 ng) or L-glutamate (3-300 ng) elicited dose-dependent depressor and bradycardic responses and greater depressor responses to both amino acids were seen at high doses in SHR, compared to WKY. Tonic neuronal activity to release L-DOPA is lost in the CVLM of adult SHR and this loss may contribute to maintenance of hypertension in SHR.
Buscar en Google
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Bulbo Raquídeo
/
Levodopa
/
Hipertensión
/
Neuronas
Límite:
Animals
Idioma:
En
Revista:
Neurosci Lett
Año:
1995
Tipo del documento:
Article
País de afiliación:
Japón