RESUMEN
Jaundiced babies undergoing phototherapy often develop diarrhoea. The cause of it is still uncertain. Increasing evidence supports a role of a secretory mechanism for the diarrhoea. We therefore studied the effects of bile from congenitally jaundiced rats undergoing phototherapy and of unconjugated bilirubin on rat small intestine in vivo and in vitro. Results suggest that: (1) the bile from homozygous Gunn rats under phototherapy has an anti-absorptive effect when tested in the perfused jejunum of normal Wistar rats; (2) unconjugated bilirubin has a dose dependent secretory effect on the intestinal transport of water and electrolytes, when tested in the same system. Alteration of cyclic AMP or cyclic GMP, known intracellular mediators of secretion, was not observed. We conclude that free bilirubin is an intestinal secretagogue acting by an as yet unknown mechanism, that may mediate the secretory type of diarrhoea in jaundiced neonates undergoing phototherapy.
Asunto(s)
Bilis/metabolismo , Bilirrubina/farmacología , Absorción Intestinal/efectos de los fármacos , Ictericia/metabolismo , Equilibrio Hidroelectrolítico/efectos de los fármacos , Animales , Transporte Biológico/efectos de los fármacos , Glucosa/metabolismo , Técnicas In Vitro , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Ictericia/congénito , Ictericia/terapia , Masculino , Nucleótidos/metabolismo , Fototerapia , Ratas , Ratas Gunn , Ratas Endogámicas , Sodio/metabolismoAsunto(s)
Bilirrubina/metabolismo , Ictericia/congénito , Adulto , Transporte Biológico , Síndrome de Crigler-Najjar/metabolismo , Enfermedad de Gilbert/metabolismo , Humanos , Hiperbilirrubinemia/metabolismo , Hiperbilirrubinemia Hereditaria/metabolismo , Recién Nacido , Ictericia/metabolismo , Ictericia Neonatal/terapia , Hígado/metabolismo , FototerapiaRESUMEN
Although phototherapy with blue fluorescent light effectively lowered the serum bilirubin concentration in congenitally jaundiced Gunn rats, no effect on red blood cell surivival as determined by chromium-51 labeling of homologous red blood cells and carboxyhemoglobin concentration was observed. Furthermore, attempts to demonstrate metabolic stress to the red blood cells failed to show increased glucose consumption. No oxidant damage to red cells as reflected by methemoglobin production and Heinz body formation was observed. Thus the anticipated hemolysis secondary to oxidant damage to red blood cells from phototherapy was not found.