Abstract: 20

STUDIES ON THE ACUTE EFFECTS OF TNF IN RAT CL CELLS.

John Carlson^{1 *}
Biology Department, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 ¹

Recent experiments indicate that generation of reactive oxygen species (ROS) affects progesterone production in the CL. LH or PGF₂ may stimulate formation of ROS. There is evidence that the cytokine TNF also induces ROS production. The present study was conducted to see whether acute treatment of TNF affects production of progesterone and ROS in rat CL cells in vitro. Luteinized ovaries from superovulated rats were removed 3-4 or 7-8 days after gonadotropin injection. The cells were dispersed with collagenase and DNase and incubated with ovine LH, human recombinant TNF, indomethacin or rotenone for 120 minutes. Treatment with 1-100 ng of LH stimulated a 5-fold increase in progesterone secretion in cells from ovaries removed 3-4 days after superovulation. However, addition of 1-1000 ng of indomethacin or 10-1000 nM rotenone inhibited LH stimulated progesterone secretion. In contrast, treatment of dispersed cells with TNF (1-100ng/500,000 cells) with or without LH failed to alter progesterone production. In a separate study, addition of LH or TNF separately or combined resulted in a small (15-25%) increase in ROS using the fluorescence probe dihydrorhodamine 123. The ability of LH and TNF to alter progesterone secretion was also examined in dispersed CL cells removed 7-8 days after superovulation. Basal progesterone secretion was higher and LH stimulation was less (~2-fold increase) than in younger CL cells. Once again, TNF₂ failed to alter progesterone secretion after 120-minute incubation. These studies indicate that under conditions of short-term incubation, TNF does not appear to affect progesterone secretion in dispersed cells from the rat CL.

    This abstract is being presented on Sunday, August 1 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.