Adenosine triphosphate induces Ca2+ signal in epithelial cells of the mouse caput epididymis through activation of P2X and P2Y purinergic receptors.
In the present study, we developed a novel method to analyze the calcium (Ca2+) signal in living slices of mouse caput epididymides by applying calcium imaging on Fura-2-loaded vibratome slices. The data revealed that in epithelial cells of mouse caput epididymides, ATP induces a rapid Ca2+ signal that is sustained after 60 sec. Preincubating the sections in Ca2+-free medium in the presence of EGTA did not affect the amplitude of the ATP-induced Ca2+ signal, indicating the presence of P2Y type purinergic receptors and phospholipase C activity. Furthermore, ATP induced a similar Ca2+ signal in the different subregions of caput epididymides. The P2X type ion-gated purinergic receptors could also be responsible for the ATP-induced Ca2+ signal because immunohistochemical and reverse transcriptase-polymerase chain reaction analyses showed that P2X1, P2X2, P2X4, P2X7, P2Y1, and P2Y2 receptors were expressed in the epididymis. We propose that P2X and P2Y receptor expression is vital for the normal function of epididymal epithelium and sperm maturation. Furthermore, the method we developed allows us to analyze the activity of various G protein-coupled receptors in intact epithelial cells of mouse epididymides, and other reproductive tissues as well.
Shariatmadari
Ramin
R
Departments of Physiology, Institute of Biomedicine, University of Turku, Turku, Finland.
Sipilä
Petra
P
Vierula
Matti
M
Törnquist
Kid
K
Huhtaniemi
Ilpo
I
Poutanen
Matti
M
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects*; D004822:Epididymis / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D007150:Immunohistochemistry; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D020033:Protein Isoforms / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism*; D058469:Receptors, Purinergic P2X; D058472:Receptors, Purinergic P2Y1; D020133:Reverse Transcriptase Polymerase Chain Reaction
C546383:P2ry1 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; D018048:Receptors, Purinergic P2; D058469:Receptors, Purinergic P2X; D058472:Receptors, Purinergic P2Y1; D000255:Adenosine Triphosphate