Intracellular free calcium in response to oxytocin in pig endometrial cells.
Intracellular free calcium concentration ([Ca2+]i) in response to oxytocin (OT) was studied in stromal, glandular epithelial and luminal epithelial cells obtained from the endometrium of gilts 16 days post-estrus. The amplitude of increased [Ca2+]i in response to 100 nM OT was greatest in stromal cells, intermediate in glandular epithelial cells and not evident in luminal epithelial cells. During continuous OT administration, stromal cells responded initially with a synchronous spike of [Ca2+]i that did not require extracellular Ca2+ and then displayed spontaneous asynchronous [Ca2+]i spikes that required extracellular Ca2+. Each cell possessed its own characteristic response. Increasing concentrations of OT induced an increasing percentage of stromal cells responding, with some cells having nearly equal [Ca2+]i responses at all concentrations and others having graded [Ca2+]i responses as the concentration of OT increased. These results are consistent with the proposed mechanism of OT action in pig endometrium involving activation of phosphoinositide-Ca2+ signaling pathway.
Braileanu
G T
GT
Department of Animal Sciences, Washington State University, Pullman 99164-6353, USA.
Simasko
S M
SM
Uzumcu
M
M
Mirando
M A
MA
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004717:Endometrium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D004971:Estrus; D005260:Female; D007700:Kinetics; D010121:Oxytocin / Q000494:pharmacology*; D017154:Stromal Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D013552:Swine
D010121:Oxytocin; D002118:Calcium