| Autor: |
C V, de-Oliveira, J A, Assumpção, Y Q, Confessor, P G, Guertzenstein, S L, Cravo |
| Rok vydání: |
1996 |
| Předmět: |
|
| Zdroj: |
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas. 29(4) |
| ISSN: |
0100-879X |
| Popis: |
Spontaneous and stimulus-induced release of isotopically labelled glycine was studied in the superfused rat dorsal or ventral medullary surface in vivo. Superfusion of the ventral medullary surface of anesthetized (urethane, 1.2 g/kg, ip) male adult Wistar rats (250-350 g) with high K+ (40 mM) surrogate cerebrospinal fluid (CSF) produced an average increase of 45% over the spontaneous efflux of exogeneously applied glycine (N = 5, P0.01). In experiments in which the calcium of the CSF was replaced by an equimolar amount of magnesium, the increase in glycine efflux in response to high K+ was reduced to 15%, a value not statistically different from that observed in control experiments (N = 6). Veratridine stimulation evoked a large (80%) increase in glycine efflux (N = 5, P0.001), which was inhibited by tetrodotoxin. High potassium or veratridine failed to modify spontaneous release of glycine on the dorsal medullary surface. Results obtained in control experiments showed that neither high K+ nor veratridine is effective in modifying spontaneous efflux of [3H]-leucine or [3H]-inulin on the ventral or dorsal medullary surface. These data support the hypothesis that glycine is a neurotransmitter on the ventral medullary surface and that it may be part of neural pathways involved in cardiorespiratory regulation present in this region. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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