Abstract |
The effects of the GABA antagonist picrotoxin, and the GABA agonist muscimol, have been studied in chronically instrumented unanaesthetized fetal sheep of 115-132 days gestation. Picrotoxin (300-400 micrograms/kg intravenous bolus injection) induced a period of stimulated breathing (40-112 min) which was associated with high voltage electrocortical activity, but inhibited by hypoxia. Muscimol (4 mg infused) had the opposite effect and caused a prolonged period of apnoea (85-418 mins) which was followed by a rebound period of increased breathing. These observations suggest that the GABA-ergic system may be involved in the apnoea of high voltage sleep states in the late gestation fetal sheep, but not in the apnoea associated with hypoxaemia in the fetus.
|
Authors | B M Johnston, P D Gluckman |
Journal | Journal of developmental physiology
(J Dev Physiol)
Vol. 5
Issue 6
Pg. 353-60
(Dec 1983)
ISSN: 0141-9846 [Print] England |
PMID | 6655226
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
|
Chemical References |
- Oxazoles
- Picrotoxin
- Muscimol
- gamma-Aminobutyric Acid
|
Topics |
- Animals
- Apnea
(physiopathology)
- Female
- Fetal Hypoxia
(physiopathology)
- Fetus
(drug effects, physiology)
- Gestational Age
- Muscimol
(pharmacology)
- Oxazoles
(pharmacology)
- Picrotoxin
(pharmacology)
- Pregnancy
- Respiration
(drug effects)
- Sheep
- gamma-Aminobutyric Acid
(physiology)
|