Involvement of the Cytoskeleton in Oxytocin Secretion by Cultured Bovine Luteal Cells

• Published in: Biology of reproduction 2005-01, Vol.72 (1), p.200-205
• Main Authors: SHIBAYA, Masami, DEPTULA, Katarzyna M, KORZEKWA, Anna, OKUDA, Kiyoshi, SKARZYNSKI, Dariusz J
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cattle; Cell Communication; Cell Culture Techniques - methods; Cell Shape - drug effects; Cells, Cultured; Colchicine - pharmacology; Cytoskeleton - drug effects; Cytoskeleton - metabolism; Dinoprost - pharmacology; Female; Fundamental and applied biological sciences. Psychology; Growth Hormone - pharmacology; Hormone metabolism and regulation; Luteal Cells - drug effects; Luteal Cells - metabolism; Mammalian female genital system; Norepinephrine - pharmacology; Oxytocin - secretion; Progesterone - secretion; Vertebrates: reproduction; Vinblastine - pharmacology
• ISSN: 0006-3363; 1529-7268
• DOI: 10.1095/biolreprod.104.032144

A number of substances have been implicated in the regulation of oxytocin (OT) secretion from bovine corpus luteum in vivo. However, isolated bovine luteal cells cultured in a monolayer lose the ability to secrete OT in response to stimulatory substances. The present study investigated how cell-to-cell contact and the cytoskeleton affect OT secretion by isolated bovine luteal cells. In experiment 1, bovine midluteal cells (Days 8–12 of the estrous cycle) were stimulated with prostaglandin F 2α (PGF 2α ; 1 μM), noradrenaline (NA; 10 μM), or growth hormone (GH; 5 nM) in two culture systems: In one system, cell monolayers were incubated in 24-well culture plates, and in the other system, aggregates of cells were incubated in glass tubes in a shaking water bath. The cells cultured in a monolayer underwent considerable spreading and showed a variety of shapes, whereas the cells cultured in glass tubes remained fully rounded during the experimental period and soon formed aggregates of cells. Although PGF 2α , NA, and GH did not stimulate OT secretion by the monolayer cells, all tested substances stimulated OT secretion by the aggregated cells ( P < 0.01). In experiment 2, the monolayer cells were pre-exposed for 1 h to an antimicrofilament agent (cytochalasin B; 1 μM) or two antimicrotubule agents (colchicine or vinblastine; 1 μM) before stimulation with PGF 2α , NA, or GH. Although PGF 2α , NA, and GH did not stimulate OT secretion by the monolayer cells in the presence of colchicine or vinblastine, they all stimulated OT secretion in the presence of cytochalasin B ( P < 0.001). The overall results show that OT secretion by bovine luteal cells depends on microfilament function and cell shape. Moreover, the aggregate culture system that allows three-dimensional, cell-to-cell contact seems to be a good model for studying OT secretion by isolated bovine luteal cells. Abstract Oxytocin secretion by luteal cells depends on the function of microfilaments