Preservation of neural function in the perinate by high PGE(2) levels acting via EP(2) receptors.
J Appl Physiol (1985)
; 89(2): 777-84, 2000 Aug.
Article
em En
| MEDLINE
| ID: mdl-10926665
ABSTRACT
Despite increasingly frequent and longer lasting hypoxic episodes during progressive labor, the neonate is alert and vigorous at birth. We investigated whether high levels of PGs during the perinatal period assist in preserving neural function after such "stressful" hypoxic events. Visual evoked potentials (VEPs) and electroretinograms (ERGs) were recorded before and 45 min after mild moderate asphyxic hypoxia (two 4-min asphyxic-hypoxic periods induced by interrupting ventilation at 8-min intervals) in newborn piglets <12 h old treated or not treated with inhibitors of PG synthase (ibuprofen or diclofenac) with or without PG analogs. At 45 min after the hypoxic episode, P2 and b-wave amplitudes were slightly decreased and latencies were delayed. These changes in the VEP and ERG returned to near normal by 120 min. Ibuprofen and diclofenac decreased brain and retinal PG levels and markedly intensified 45 min after hypoxia-induced changes in VEP and ERG, but cerebral and retinal blood flows improved. Combined treatment with PG synthase inhibitor in combination with 16,16-dimethyl-PGE(2) (a PGE(2) analog), but not with PGI(2) and PGF(2alpha) analogs, and in combination with the EP(2) receptor agonist butaprost (but not EP(1) or EP(3) agonists), prevented ibuprofen- and diclofenac-aggravated postasphyxia electrophysiological changes. In conclusion, high levels of PGE(2) in nervous tissue, via actions on EP(2) receptors, seem to contribute to preservation of neural function in the perinate subjected to frequent hypoxic events.
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Base de dados:
MEDLINE
Assunto principal:
Retina
/
Encéfalo
/
Dinoprostona
/
Receptores de Prostaglandina E
/
Animais Recém-Nascidos
Limite:
Animals
Idioma:
En
Revista:
J Appl Physiol (1985)
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Canadá