Inositol triphosphate participates in an oestradiol nongenomic signalling pathway involved in accelerated oviductal transport in cycling rats

Pedro A. Orihuela, Alexis Parada-Bustamante, Lidia M. Zuñiga, Horacio B. Croxatto

Resultado de la investigación: Contribución a una revistaArtículo

25 Citas (Scopus)

Resumen

Oestradiol (E2) accelerates oviductal transport of oocytes in cycling rats through a nongenomic pathway that involves the cAMP-PKA signalling cascade. Here we examined the role of the inositol triphosphate (IP3) and mitogen-activated protein kinase (MAPK) signalling cascades in this nongenomic pathway. Oestrous rats were injected with E2 s.c. and intrabursally (i.b) with the selective inhibitors of phospholipase C (PLC) ET-18-OCH3 or MAPK PD98059. The number of eggs in the oviduct assessed 24h later showed that ET-18-OCH3 blocked E2-induced egg transport acceleration, whereas PD98059 had no effect. Other oestrous rats were treated with E2 s.c. and 1, 3 or 6 h later oviducts were excised and the levels of IP3 and phosphorylated MAPK p44/42 (activated) were determined by radioreceptor assay and western blot, respectively. Oestradiol administration increased IP3 level at 1 and 6 h after treatment, whereas activated MAPK p44/42 level was unchanged. Finally, we explored whether cAMP-PKA and PLC-IP3 signalling cascades are coupled. Inhibition of adenylyl cyclase by i.b. injection of SQ 22536 blocked the increase of IP3 levels induced by E2, while inhibition of PLC by ET-18-OCH3 had no effect on E2-induced PKA activity. Furthermore, activation of adenylyl cylase by Forskolin increased oviductal IP3 levels. Thus, activation of PLC-IP3 by E2 requires previous stimulation of cAMP-PKA. We conclude that the nongenomic pathway utilised by E2 to accelerate oviductal transport of oocytes in cycling rats involves successive activation of the cAMP-PKA and PLC-IP3 signalling cascades and does not require activation of MAPK. These findings clearly illustrate a non-genomic pathway triggered by E2 that regulates a complex physiologic process accomplished by an entire organ.

Idioma originalInglés
Páginas (desde-hasta)579-588
Número de páginas10
PublicaciónJournal of Endocrinology
Volumen188
N.º3
DOI
EstadoPublicada - mar 2006

Áreas temáticas de ASJC Scopus

  • Endocrinología
  • Endocrinología, diabetes y metabolismo

Huella Profundice en los temas de investigación de 'Inositol triphosphate participates in an oestradiol nongenomic signalling pathway involved in accelerated oviductal transport in cycling rats'. En conjunto forman una huella única.

  • Citar esto