|Wulster Radcliffe, Meghan|
Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2002
Publication Date: 5/4/2003
Citation: Wulster-Radcliffe, M.C., Seals, R.C., Lewis, G.S. Progesterone increases the susceptibility of gilts to uterine infections after intrauterine inoculation with infectious bacteria. Journal of Animal Science. 2003. v. 81. p. 1242-1252. Interpretive Summary: Uterine infections are a major problem in ruminants. However, the extent of the problem in swine is not clear. It is assumed that, because of management conditions and syndromes with uterine infections as a component, uterine infections are a major problem in the swine industry. Gilts seem to be an ideal model for studying uterine infections. Changes in steroid concentrations, particularly increases in progesterone regulate immune cell function, and changes in immune cell function are related to the susceptibility of an animal to uterine infections. Infection induced increases in uterine prostaglandin production may promote the movement of immune cells into the uterus. Treatments with PGF2alpha may be useful for modulating uterine immune function and reducing the incidence of uterine infections in pigs.
Technical Abstract: In cattle and sheep, a progestogenated uterus is susceptible to infections, but this is not well characterized in gilts. Therefore, the effects of day of the estrous cycle (DOC) and progesterone (P4) were evaluated. Gilts (n = 5/group) were assigned to treatments in 2 2 factorial arrays. In Exp. 1, DOC and bacterial challenge (BC) were main effects. On d 0 or 8, uteri were inoculated with either 70 10**7 cfu of Escherichia coli and 150 10**7 cfu of Arcanobacterium pyogenes in PBS (10 mL) or PBS. In Exp. 2, ovariectomy (OVEX) and P4 supplementation were main effects. On d 0, gilts were OVEX or a sham procedure was performed. After surgery, gilts received i.m. injections of P4 (10 mg/5 mL) or 5 mL of safflower diluent twice daily. On d 8, gilts were inoculated with the same doses of bacteria as in Exp. 1. In Exp. 1 and 2, vena caval blood was collected for 4 d, gilts were killed, and uteri were collected. Sediment (packed-cell volume; PCV) and ability to culture E. coli and A. pyogenes from uterine flushings were used to diagnose infections. Differential white blood cell counts and proliferative response of lymphocytes exposed to the mitogens concanavalin A (Con A) and lipopolysaccharides (LPS) were used to evaluate immune cell function. Progesterone, estradiol-17beta, PGF2alpha, and PGE2 were measured in vena caval blood. Day of estrous cycle and P4 supplementation changed the uterine immune response to infectious bacteria in gilts.