Dose-and-time dependent effect of 2,3,7,8-tetrachlorodibenzo-P-dioxin (TCDD) on progesterone secretion by porcine luteal cells cultured in vitro.
In the current study, to characterize TCDD action during luteal phase of the ovarian cycle, the direct effect of TCDD was investigated in vitro using a system of monolayer cell culture. Luteal cells isolated from mid-developing corpora lutea were cultured with four different doses of TCDD (0.1, 1.0, 10.0 and 100 nM). The dose of 0.1nM TCDD had no effect on progesterone (P4) secretion by luteal cells while the doses of 10nM and 100nM in the same, statistically significant manner decreased P4 secretion (p <0.05). The inhibitory effect of TCDD was dependent not only on doses by also on experimental conditions. In cells treated every day for 72 hrs of culture with 0.1nM TCDD, P4 secretion was 71% of basal secretion. 100nM TCDD added only at the beginning of the culture and nor repeated when medium was changed every 24 hrs decreased P4 secretion to 81.8% of basal secretion. The most inhibitory effect was observed in experiments in which 100nM TCDD was added at the beginning of the culture and medium was not changed for 72 hrs. Secretion of P4 was only 33.9% of that by control cultures. In order to show the time-dependent response to TCDD in terms of P4 secretion, luteal cells were cultured for 24,48, 72 hrs with 0.1 and 100nM TCDD. 85%, 75% and 72% of basal progesterone secretion was noted after 24, 48 and 72h respectively in 0.1nM TCDD-treated cells. In 100nM TCDD treated cells the decrease of progesterone secretion was 57%, 67% and 82% of basal secretion after 24, 48 and 72 hrs of culture. These experiments suggest that TCDD by suppressing progesterone secretion by corpora lutea can cause adverse reproductive effects such as early pregnancy failure. Endocrine disrupters that interfere with progesterone production can act as abortifacients.
Gregoraszczuk
E L
EL
Department of Animal Physiology, Institute of Zoology, Jagiellonian University, Cracow, Poland. greg@zuk.iz.uj.edu.pl
Wójtowicz
A K
AK
Zabielny
E
E
Grochowalski
A
A
D000818:Animals; D002478:Cells, Cultured; D003338:Corpus Luteum / Q000166:cytology / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004785:Environmental Pollutants / Q000494:pharmacology*; D005260:Female; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D011374:Progesterone / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D013552:Swine; D013997:Time Factors
D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D011374:Progesterone