title: Collagen and matrix metalloproteinase-2 and -9 in the ewe cervix during the estrous cycle.
abstract: The cervical collagen remodeling during the estrous cycle of the ewe was examined. The collagen concentration determined by a hydroxyproline assay and the area occupied by collagen fibers (%C), determined by van Gieson staining, were assessed in the cranial and caudal cervix of Corriedale ewes on Days 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (defined as Day 0). In addition, the gelatinase activity by in situ and SDS-PAGE gelatin zymographies and matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9, respectively) expression by immunohistochemistry were determined. The collagen concentration and %C were lowest on Day 1 of the estrous cycle (P < 0.04), when MMP-2 activity was highest (P < 0.006) and the ratio of activated to latent MMP-2 trend to be highest (P = 0.0819). The MMP-2 activity was detected in 73% of the homogenized cervical samples, and its expression was mainly detected in active fibroblasts. By contrast, the MMP-9 activity was detected in 9% of the samples, and its scarce expression was associated with plasmocytes, macrophages, and lymphocytes. Matrix metalloproteinase-2 expression was maximal on Day 1 in the cranial cervix and on Day 13 in the caudal cervix and was lower in the cranial than in the caudal cervix (P < 0.0001). This time-dependent increase in MMP-2 expression that differed between the cranial and caudal cervix may reflect their different physiological roles. The decrease in the collagen content and increase in fibroblast MMP-2 activity in sheep cervix on Day 1 of the estrous cycle suggests that cervical dilation at estrus is due to the occurrence of collagen fiber degradation modulated by changes in periovulatory hormone levels.
authors.affiliation: Biochemistry Area, Department of Molecular and Cellular Biology, Universidad de la República, Montevideo, Uruguay. Electronic address: marodri@adinet.com.uy.
authors.forename: M
authors.initials: M
authors.lastname: Rodríguez-Piñón
authors.affiliation: Biochemistry Area, Department of Molecular and Cellular Biology, Universidad de la República, Montevideo, Uruguay.
authors.forename: C
authors.initials: C
authors.lastname: Tasende
authors.affiliation: Biochemistry Area, Department of Molecular and Cellular Biology, Universidad de la República, Montevideo, Uruguay.
authors.forename: D
authors.initials: D
authors.lastname: Casuriaga
authors.affiliation: Histology and Embryology Area, Department of Morphology and Development, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay.
authors.forename: A
authors.initials: A
authors.lastname: Bielli
authors.affiliation: Histology and Embryology Area, Department of Morphology and Development, Veterinary Faculty, Universidad de la República, Montevideo, Uruguay.
authors.forename: P
authors.initials: P
authors.lastname: Genovese
authors.affiliation: Biochemistry Area, Department of Molecular and Cellular Biology, Universidad de la República, Montevideo, Uruguay.
authors.forename: E G
authors.initials: EG
authors.lastname: Garófalo
mesh_terms: D000818:Animals; D002584:Cervix Uteri / Q000378:metabolism*; D003094:Collagen / Q000378:metabolism*; D030762:Estrous Cycle; D005260:Female; D007150:Immunohistochemistry; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism / Q000502:physiology*
chemical_list: D003094:Collagen; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9
keywords: Cervical remodeling; Collagen; Estrous cycle; Ewe; Metalloproteinase