Progesterone inhibition of water permeability in bufo arenarum
oocytes and urinary bladder.
Ford, Paula, Gabriela Amodeo, Claudia Capurro, Cristina Ibarra,
Ricardo Dorr, Pierre Ripoche, and Mario Parisi.
Laboratorio de Biomembranas, Departamento de Fisiolog[acute]ia,
Facultad de Medicina, Universidad de Buenos Aires, Argentina, and
Service de Biologie Cellulaire, D[acute]epartement de Biologie,
Cellulaire et Mol[acute]eculaire, CE Saclay, France
APStracts 2:0179F, 1995.
The ovarian oocytes from Bufo arenarum (BAOs) but not those from
Xenopus laevis (XLOs) would have water channels (WCs). We now report
that the injection of the mRNA from BAOs into the oocytes from XLOs
increased their water osmotic permeability (Pf) (reduced by 0.3 mM
HgCl2 and reversed by 5 mM [beta]-mercaptoethanol). A 30 min
challenge with progesterone (PGR) induced, 18 h later, a reduction of
the mercury-sensitive fraction of Pf in the BAOs (but not in XLOs).
The mRNA from BAOs pretreated with PGR lost its capacity to induce
WCs in the XLOs but the hormone did not affect the expression of the
WCs in XLOs previously injected with the mRNA from BAOs. Pf was also
measured in urinary bladders of Bufo arenarum. Eighteen hours after a
challenge with PGR, a reduction in the hydrosmotic response to
oxytocin was observed. Finally the mRNA from the urinary bladder of
Bufo arenarum was injected into XLOs. An increase in Pf was observed.
This was not the case if before the mRNA extraction, the bladders
were treated with PGR. We conclude that the BAOs WCs share PGR
sensitivity with the oxytocin regulated water channel present in the
toad urinary bladder.
Received 5 June 1995; accepted in final form 13 September 1995.
APS Manuscript Number F181-5.
Article publication pending Am. J. Physiol. (Renal Fluid Electrolyte
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95