Effect of ATP and platelet-activating factor on intracellular calcium concentrations of cultured oviductal cells from cows

• Published in: Journal of reproduction & fertility Vol. 108; no. 1; pp. 1 - 9
• Main Authors: Tiemann, U, Neels, P, Küchenmeister, U, Walzel, H, Spitschak, M
• Format: Journal Article
• Language: English
• Published: England Society for Reproduction and Fertility 01.09.1996
• Subjects: Adenosine Triphosphate - pharmacology; Animals; Calcium - metabolism; Cattle; Cells, Cultured; Estrus - metabolism; Fallopian Tubes - cytology; Fallopian Tubes - drug effects; Fallopian Tubes - metabolism; Female; Image Processing, Computer-Assisted; Intracellular Fluid - drug effects; Intracellular Fluid - metabolism; Platelet Activating Factor - pharmacology; Pregnancy; Spectrometry, Fluorescence
• ISSN: 1470-1626; 0022-4251; 1741-7899
• DOI: 10.1530/jrf.0.1080001

Oviductal endosalpingeal cells were mechanically isolated from heifers at different reproductive stages (cyclic: days 8–14 at oestrus: day 0 and pregnant: day 7) and cultured until 100% confluent. The cells were loaded with the Ca 2+ -sensitive fluorochrome fura-2/AM, and cytosolic free calcium ([Ca 2+ ] i ) was monitored spectrofluorimetrically and by use of a microscope image analysis system. ATP (400 μmol l −1 ) evoked a prompt increase in Ca 2+ ] i in all cell preparations in both the presence or absence of extracellular Ca 2+ when measured with the cuvette method. Single cell measurements using oviductal cells from cyclic heifers revealed a heterogeneous [Ca 2+ ] i pattern in response to ATP, with some cells either failing to respond or reacting very slowly. Platelet-activating factor (PAF, 30 nmol l −1 ) induced a rapid increase in [Ca 2+ ] i especially in cells derived from cyclic and pregnant animals, but the effect was significantly less in cells from heifers at oestrus. The increase in [Ca 2+ ] i in bovine cells induced by PAF was reduced when extracellular calcium was depleted, indicating that the effect of PAF on [Ca 2+ ] i involves an influx from the extracellular space. Voltage-sensitive calcium channels do not appear to be involved in the influx of extracellular Ca 2+ since verapamil had no effect on the PAF-induced increase in [Ca 2+ ] i . The PAF receptor antagonist WEB 2086 inhibited the PAF-mediated effects on [Ca 2+ ] i .