Effect of prostaglandin F2 alpha on cytosolic free calcium ion concentrations in rat luteal cells.
Changes in cytosolic free calcium concentrations [( Ca2+]i) in response to prostaglandin F2 alpha (PGF2 alpha) were measured in single rat luteal cells, using the calcium-sensitive fluorescent dye fura-2. A total of 112 cells were studied in 20 experiments. The average resting [Ca2+]i was 113 +/- 6.4 nM. In 59 cells (53%), there was a 4.6 +/- 0.2-fold increase in [Ca2+]i within 29.3 +/- 1.0 sec of PGF2 alpha administration, and the cells recovered by 78.0 +/- 4.5 sec. The magnitude of the increase in [Ca2+]i in response to PGF2 alpha was not changed by an increase in the concentration of PGF2 alpha. Perifusion with low calcium buffer reduced, then eliminated, the [Ca2+]i response to PGF2 alpha. Perifusion of cells with PGF2 alpha resulted in a single transient [Ca2+]i response, similar to that after short term exposure to PGF2 alpha. Many (67%) of the cells that responded to PGF2 alpha also responded to GnRH. No additive increase in [Ca2+]i was seen when PGF2 alpha and GnRH were administered together. The source of the calcium appears to be intracellular stores that are shared by GnRH and PGF2 alpha.
Rodway
M R
MR
Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, Canada.
Baimbridge
K G
KG
Yuen
B H
BH
Leung
P C
PC
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D015237:Dinoprost / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005456:Fluorescent Dyes; D016257:Fura-2; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology; D008184:Luteal Cells / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains
D005456:Fluorescent Dyes; D007987:Gonadotropin-Releasing Hormone; D015237:Dinoprost; D002118:Calcium; D016257:Fura-2