Adenosine mediates metabolic and cardiovascular responses to hypoxia in fetal sheep.
J Physiol
; 488 ( Pt 3): 761-6, 1995 Nov 01.
Article
en En
| MEDLINE
| ID: mdl-8576865
ABSTRACT
1. In seven unanaesthetized fetal sheep (> 80% term), isocapnic hypoxia (arterial partial pressure of O2, Pa,O2, approximately 15 mmHg) was induced for 1 h by lowering maternal inspired PO2. Fetal hypoxia was also produced during intra-arterial administration of the adenosine receptor antagonist 8-(p-sulphophenyl)-theophylline (8-SPT). The fetal 8-SPT infusion was begun just prior to hypoxia and was stopped when fetal Pa,O2 was returned to normal. 2. Hypoxia induced a progressive fetal acidosis, a rise in mean arterial pressure, a transient fall in heart rate and a decrease in breathing movements. 8-SPT significantly reduced the metabolic acidosis and abolished the hypertension and bradycardia without altering hypoxic inhibition of fetal breathing. Administration of the vehicle for 8-SPT during hypoxia did not significantly affect the normal fetal metabolic and cardiovascular responses to acute O2 deprivation. 3. It is concluded that adenosine mediates the fetal bradycardia and hypertension produced by hypoxia, indicating that adenosine modulates fetal autonomic responses to acute oxygen deficiency. Secondly, adenosine contributes to fetal metabolic acidaemia, suggesting that adenosine also modulates fetal glycolytic responses to hypoxia.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Adenosina
/
Feto
/
Hipoxia
Límite:
Animals
/
Pregnancy
Idioma:
En
Revista:
J Physiol
Año:
1995
Tipo del documento:
Article
País de afiliación:
Estados Unidos