Translator Disclaimer
1 May 2002 Analysis of Luteal Tissue Inhibitor of Metalloproteinase-1, -2, and -3 During Prostaglandin F-Induced Luteolysis
Author Affiliations +

Increased matrix metalloproteinase (MMP) expression and activities help to mediate tissue involution through increasing extracellular matrix remodeling and promoting dedifferentiation and, ultimately, apoptosis. Therefore, we hypothesized that prostaglandin (PG) F administration would decrease expression of the tissue inhibitor of metalloproteinase (TIMP)-1, -2, and -3 and effectively increase the MMP:TIMP ratio, leading to glandular involution. In experiment 1, we tested the effects of PGF administration (Day 10 postestrus; Day 0 = estrus) on luteal TIMP-1, -2, and -3 mRNA and protein expression. Corpora lutea were collected at 0, 15, or 30 min or at 1, 2, 4, 6, 12, 24, and 48 h following PGF administration (n = 3–9 animals/time point). Following PGF administration, TIMP-1 mRNA levels decreased (P < 0.05) at 1 and 2 h relative to 0 h (controls), then increased to levels greater than controls at 4 and 6 h. In contrast, TIMP-2 and -3 mRNA levels did not decrease following PGF administration. The TIMP-1, -2, and -3 proteins were localized to large luteal cells (LLCs) within control (untreated) tissues. However, histodepletion of TIMP-1 within LLCs was evident within 30 min (earliest time point collected) following PGF injection and continued through 48 h. Luteal concentration of TIMP-1, as determined by RIA, was decreased (P < 0.05) by 15 min (earliest time point collected) following PGF administration and remained low through 48 h. In contrast, TIMP-2 and -3 immunolocalization was not altered by PGF administration. Experiment 2 was conducted to determine if PGF could initiate the preceding changes in TIMP-1 in early (Day 3) corpora lutea that can bind PGF but are refractory to its luteolytic effects. Serum concentrations of progesterone and luteal concentrations of TIMP-1 mRNA and protein were similar at 0 and 6 h after PGF injection on Day 3 postestrus. These data suggest that an early and sustained effect of PGF is the specific depletion of TIMP-1 within LLCs that are capable of responding to the luteolytic action of PGF. This action may increase the MMP:TIMP-1 ratio, creating an environment that favors extracellular matrix degradation and, thereby, facilitates both functional and structural regression.

William A. Ricke, George W. Smith, Eric W. McIntush, and Michael F. Smith "Analysis of Luteal Tissue Inhibitor of Metalloproteinase-1, -2, and -3 During Prostaglandin F-Induced Luteolysis," Biology of Reproduction 66(5), 1387-1394, (1 May 2002).
Received: 16 April 2001; Accepted: 1 December 2001; Published: 1 May 2002

This article is only available to subscribers.
It is not available for individual sale.

Get copyright permission
Back to Top