Evaluation of progesterone, estrogens and placental lactogen in pregnant ewes following experimental infection with an abortive agent chlamydia psittaci "Var-Ovis".
The plasma levels of progesterone, free and conjugated estrone and of placental lactogen have been determined in three groups of pregnant ewes inoculated with an abortive agent (Chlamydia psittacci var. ovis) on day 66 of gestation. In the control group, ewes were immunized against this abortive agent, and lambed after a normal duration of pregnancy; the blood levels of the three studied hormones showed normal patterns. In the two other groups, the ewes which were not immunized, had a shortened gestation and gave birth in most cases to dead lambs. In some animals, plasma levels of estrone followed an apparently normal evolution; in others the amplitude of the prepartum rise was lower than in the control group. Moreover, plasma levels of progesterone and of placental lactogen were lower in the animals which aborted than in the controls. This effect on the secretion of these two placental hormones probably reflects the action of the abortive agent on the placenta.
Bosc
M J
MJ
I.N.R.A. - Station de Physiologie de la Reproduction, 37380 Nouzilly, France.
Djiane
J
J
Nicolle
A
A
Rodolakis
A
A