The effect of chlamydial infection on the initiation of premature labour: serial measurements of intrauterine prostaglandin E2 in amniotic fluid, allantoic fluid and utero-ovarian vein, using catheterised sheep experimentally infected with an ovine abortion strain of Chlamydia psittaci.
The initiation of premature labour by an ovine abortion strain of Chlamydia psittaci was studied in relation to Prostaglandin E2 (PGE2), which plays a major role in parturition. The local intrauterine concentration of PGE2 was monitored after experimental infection with C. psittaci, during late gestation, using a catheterised sheep model. Indwelling catheters were implanted into the amniotic and allantoic cavities of six control sheep, and into six sheep infected with an ovine abortion of C. psittaci. The release of PGE2 into the utero-ovarian vein of these sheep was also monitored. Infection with C. psittaci was associated with a premature rise in PGE2 in the amniotic fluid between days 122 and 135 of gestation (P less than 0.01). A premature increase in PGE2 was defected between days 127 and 136 of gestation (P less than 0.05) in the allantoic fluid of sheep infected with C. psittaci, but not in the control uninfected sheep. Chlamydial infection significantly decreased the secretion of PGE2 into the utero-ovarian vein. The mean concentration of PGE2 in the utero-ovarian vein of infected sheep was 68.8 +/- 5.2% of the PGE2 concentration of control sheep between days 122 to 141 of gestation (P less than 0.01). The release of PGE2 into the utero-ovarian vein increased between days 126 to 136 of gestation in infected and control sheep (P less than 0.01). The results from the catheterised sheep model indicated that C. psittaci infection is associated with a local intrauterine release of PGE2. The magnitude of this release was similar to the PGE2 release in control sheep prior to parturition.(ABSTRACT TRUNCATED AT 250 WORDS)
Howie
A
A
Blood Transfusion Centre, Edinburgh, UK.
Leaver
H A
HA
Aitken
I D
ID
Hay
L A
LA
Anderson
I E
IE
Williams
G E
GE
Jones
G
G
D000481:Allantoin / Q000378:metabolism; D000653:Amniotic Fluid / Q000378:metabolism*; D000818:Animals; D002408:Catheters, Indwelling; D002690:Chlamydia Infections / Q000503:physiopathology*; D015232:Dinoprostone / Q000378:metabolism*; D005260:Female; D005865:Gestational Age; D007751:Labor, Induced; D010053:Ovary / Q000098:blood supply / Q000378:metabolism; D011247:Pregnancy; D011863:Radioimmunoassay; D012756:Sheep; D014471:Umbilical Veins / Q000378:metabolism*; D014599:Uterus / Q000098:blood supply / Q000378:metabolism
D000481:Allantoin; D015232:Dinoprostone