Porcine lymphocytes secrete a bioactive and immunoreactive LH-like factor in response to LHRH and concanavalin A.
Lymphocyte conditioned medium (CM) was prepared by incubating 0 (cell-free control) or 4 x 10(6) lymphocytes/ml in serum-supplemented RPMI containing 0, 10(-9), 10(-7), and 10(-5) M luteinizing hormone releasing hormone (LHRH), 10(-5) M LHRH antagonist (LHRHA), or 10(-7) M LHRH + 10(-5) M LHRHA. Treatments were applied with and without 10 micrograms/ml concanavalin A (con A), and media were analyzed for LH. Aliquots of the CM from cultures incubated for 48 h were later applied to porcine granulosa cell cultures (suspended to 1.25 x 10(5) cells in 450 mul). Thereafter, 50 mul of CM were added to granulosa cell cultures. Media were collected after 12, 24, and 48 h and progesterone determined. Immunoreactive LH increased with time of incubation in lymphocyte CM but not cell-free CM. LH content of lymphocyte CM increased as LHRH concentration increased. LHRHA significantly reduced the amount of LH measured. The presence of con A in the medium resulted in maximal concentrations of LH, irrespective of dose of LHRH or LHRHA. Cell-free CM containing LHRH, LHRHA, and/or con A did not affect progesterone production by granulosa cells at any of the time periods. Lymphocyte CM containing LHRH caused a dose-dependent increase in progesterone production at 48 h. This stimulation was blocked by lymphocyte CM containing LHRHA. Lymphocyte CM containing con A also stimulated progesterone production at all of the LHRH concentrations studied. This response was not inhibited by lymphocyte CM containing the LHRHA.(ABSTRACT TRUNCATED AT 250 WORDS)
Standaert
F E
FE
Department of Animal Sciences, Washington State University, Pullman, Washington 99164-6320.
Chew
B P
BP
Wong
T S
TS
Michal
J J
JJ
D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology*; D004247:DNA / Q000096:biosynthesis; D004305:Dose-Response Relationship, Drug; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D006107:Granulosa Cells / Q000378:metabolism; D066298:In Vitro Techniques; D007986:Luteinizing Hormone / Q000096:biosynthesis*; D008214:Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis; D011863:Radioimmunoassay; D013552:Swine; D013997:Time Factors
D003208:Concanavalin A; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D007986:Luteinizing Hormone; D004247:DNA