title: Expression of monocyte chemoattractant protein-1 in the corpus luteum of the rat.
abstract: The known accumulation of macrophages in corpora lutea (CL) at the time of luteal regression prompted us to investigate whether the chemoattractant protein monocyte chemoattractant protein-1 (MCP-1) is expressed in the rat CL. On the day of confirmed mating (Day 0 of pregnancy), regressing CL from the previous (nonfertile) estrous cycle contained immunodetectable MCP-1 and numerous monocytes/macrophages, whereas the newly formed CL of pregnancy, within the same ovary, contained little MCP-1 and few monocytes/macrophages. MCP-1 diminished in the regressing CL on Days 3 and 9 of pregnancy, although numerous monocytes/macrophages remained. The CL of pregnancy on Days 3 and 9 of pregnancy contained minimal MCP-1 and relatively few monocytes/macrophages. By Days 17 and 21 of pregnancy, however, prior to parturition and prior to an accumulation of monocytes/macrophages, expression of MCP-1 increased in the CL of pregnancy. Northern blots revealed a resurgence of luteal MCP-1 mRNA on Day 21 of pregnancy: 3805 +/- 1077 on Day 21 vs. 1059 +/- 177 on Day 9 (p < 0.05; expressed as densitometric units relative to beta-actin). In conclusion, the expression of MCP-1 in the rat CL in association with, or preceding, the appearance of monocytes/macrophages at the time of luteal regression is consistent with the known role of MCP-1 as a potent chemoattractant for monocytes/macrophages. This suggests that MCP-1 might have a prominent role in the immunological process of luteal regression.
authors.affiliation: Department of Physiology, University of Michigan Medical School, Ann Arbor 48109-0622, USA. townson@umich.edu
authors.forename: D H
authors.initials: DH
authors.lastname: Townson
authors.forename: J S
authors.initials: JS
authors.lastname: Warren
authors.forename: C M
authors.initials: CM
authors.lastname: Flory
authors.forename: D M
authors.initials: DM
authors.lastname: Naftalin
authors.forename: P L
authors.initials: PL
authors.lastname: Keyes
mesh_terms: D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D018932:Chemokine CCL2 / Q000032:analysis / Q000235:genetics*; D003338:Corpus Luteum / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D007150:Immunohistochemistry; D003341:Luteolysis; D008264:Macrophages; D008969:Molecular Sequence Data; D009000:Monocytes; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D018932:Chemokine CCL2; D012333:RNA, Messenger