IgA in uterine tissue: effect of estrous cycle, hormone treatment and intrauterine immunization.
In order to determine whether uteri synthesize and store IgA, rats were sacrificed and uterine tissues placed in organ culture for 24 h under the following conditions: (i) at various stages of the estrous cycle, (ii) following ovariectomy and treatment with estradiol, and (iii) after intrauterine immunization with sheep red blood cells (SRBC). When IgA was analyzed in tissues both prior to and following organ culture and in incubation media, no significant increases in total IgA were observed, nor was IgA release into media reduced when cycloheximide, a potent inhibitor of protein synthesis, was present. Analysis of uterine tissues indicated that IgA levels remained relatively constant throughout the estrous cycle and was not markedly increased when ovariectomized rats were treated with estradiol (2 micrograms/day) for 3 days. These results indicate that tissue IgA levels remain relatively constant even during estradiol treatment, when uterine luminal IgA levels are known to increase markedly. Analysis of ovariectomized rats that received intrauterine immunizations with SRBC indicated tenfold greater amounts of IgA in immunized tissues than did uteri from intact or ovariectomized animals. Despite this, no evidence of protein synthesis was obtained, based on measurements of total IgA content before and after organ culture or inhibition of IgA synthesis by cycloheximide. These results indicate that IgA synthesis under the conditions examined is not occurring, but that uterine tissue may serve as a significant storage depot for IgA synthesized either distal to or within uterine tissues at times other than those analyzed in the present study.
Steele
M G
MG
Department of Physiology, Dartmouth Medical School, Hanover, NH 03756.
Wira
C R
CR
D000818:Animals; D003600:Cytosol / Q000276:immunology; D004958:Estradiol / Q000494:pharmacology*; D004971:Estrus / Q000276:immunology*; D005260:Female; D007114:Immunization; D007070:Immunoglobulin A / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D014599:Uterus / Q000187:drug effects / Q000276:immunology* / Q000502:physiology
D007070:Immunoglobulin A; D004958:Estradiol