GRANULOCYTE MACROPHAGE COLONY STIMULATING FACTOR (GM-CSF) IN THE MURINE REPRODUCTIVE-TRACT - STIMULATION BY SEMINAL FACTORS

The activity of GM-CSF during early pregnancy in the murine uterine lumen in vivo and in media conditioned by uterine cells in vitro has been assessed. GM-CSF was detected in uterine luminal fluid recovered by lavage on the morning after syngeneic mating (median level 5-7 CFUc U/uterus) and following mating with vasectomized (5. 1 U/uterus) or allogeneic males (4-4 U/uterus), with significantly lesser (P <0-05) amounts recovered from the uteri of superovulated, mated mice. By contrast, GM-CSF was only detectable (>0-5 U/uterus) in the luminal fluid of three of 22 unmated oestrous mice examined. No activity was detected in secretions from male accessory glands including seminal vesicle, epididymis, prostate and coagulating gland (<0-5 U/gland). GM-CSF was found at higher levels in supernatants from cell monolayers prepared by tryptic digest of the uteri of Day 1 mated mice than those from unmated oestrous mice (P < 0-05). Little GM-CSF was detected in supernatants from ovariectomized mice. An a-GM-CSF polyvalent antibody neutralized the FD5/12 bioassay response confirming the identity of the lymphokine. The interleukins 11-2 and 11-3 were not detected in uterine luminal fluid nor in media conditioned by cell monolayers. We postulate that elevated uterine GM-CSF activity after mating is elicited by a non-sperm associated, non-MHC component of the ejaculate and synthesized by a hormone-responsive endometrial cell population. This cytokine may have an embryotrophic role or contribute to priming of the uterus for implantation. © 1990 CSIRO. All Rights Reserved.