Inhibitors of Mammalian Tissue Collagenase and Metalloproteinases Suppress Ovulation in the Perfused Rat Ovary*

Abstract

We have examined the effects of a new synthetic inhibitor of mammalian tissue collagenase, CI-1 (N-[3-N-(benzyloxycarbonyl)amino-1-(R)carboxypropyl]L-leucyl-O-methyl-L- tyrosine N-methylamide; G. D. Searle SC 40827), and a general metalloproteinase inhibitor, 1,10-phenanthroline, on ovulation, as judged by the observation of follicular rupture, and on progesterone production of the perfused rat ovary. Ovaries of PMSG (20 IU)-primed rats were perfused for 21 h, and samples of medium were taken for analysis of progesterone concentration. The number of ovulations was estimated by counting the number of oocytes released into the perfusion chamber. Ovaries were stimulated with LH (0.1 micrograms/ml) plus 3-isobutyl-1-methylxanthine (IBMX; 0.2 mM), and this treatment resulted in a mean of 17.2 ovulations/treated ovary. 1,10-Phenanthroline dose-dependently inhibited ovulation, with 0, 0.2, and 12.5 ovulations/treated ovary at 1.0, 0.1, and 0.01 mM, respectively. This inhibition of ovulation closely paralleled the inhibition of extracted collagenase from uterus and ovary. However, 1,10-phenanthroline also suppressed progesterone release in a dose-dependent manner. Addition of the collagenase inhibitor (CI-1; 25 microM) 1 h after LH plus IBMX inhibited ovulation (6.3 ovulations/treated ovary). Its relatively inactive stereoisomer (CI-2; 25 microM) did not suppress ovulation (20.0 ovulations/treated ovary). CI-1 inhibited extracted uterine collagenase 50% at a concentration of 2 microM, whereas CI-2 was only 1/15th as effective. There was an 80% loss of CI-1 from the medium during the perfusions. Neither CI-1 nor CI-2 had any effect on LH plus IBMX-stimulated progesterone release. These data demonstrate that the general metalloproteinase inhibitor 1,10-phenanthroline is able to inhibit ovulation, but also inhibits steroidogenesis. The more specific inhibitor of collagenase, CI-1, can inhibit ovulation without affecting steroid production. These data indicate an important role for collagenase in the ovulatory process.

Differential expression of matrix metalloproteinases during stimulated ovarian recrudescence in Siberian hamsters (Phodopus sungorus)

“…Although inhibition of ovarian MMPs can reduce or inhibit ovulation, this appears to be dependent on species and methodology. Synthetic inhibitors of collagenase significantly reduced ovulation in PMSG or eCG-primed perfused rat ovaries (Brännström et al, 1988;Butler et al, 1991), and ovulation was blocked with administration of an anti-MMP-2 antibody in PGF (2alpha) and GnRH primed sheep (Gottsch et al, 2002). Despite these correlations, other studies do not clearly identify a role for MMPs during ovulation or corpus luteum function.…”

Tumor Necrosis Factor-α-Induced Matrix Proteolytic Enzyme Production and Basement Membrane Remodeling by Human Ovarian Surface Epithelial Cells

“…In cell culture, Kruk et al (10) have demonstrated the capacity of human ovarian surface epithelial (HOSE) cells to secrete serine proteases and matrix metalloproteinases (MMPs), as well as to lyse Matrigel, although how these activities are regulated has not been explored. Several lines of evidence have implicated that both the MMP and plasminogen activator system contribute to the proteolytic activity needed at the time of ovarian rupture during ovulation (11,12), e.g., an increase in plasminogen activator and MMP activities has been detected during the preovulatory period (18 -20), and synthetic MMP inhibitors suppressed ovulation in perfused rat ovaries (21,22).…”

Pituitary adenylate cyclase-activating polypeptide acts synergistically with relaxin in modulating ovarian cell function in rats

“…The ovulatory process involves the remodeling of extracellular matrix which is executed by MMPs and plasminogen activators. Several studies have demonstrated that adminstration of inhibitors of MMPs and antibodies to plasminogen activator suppresses ovulation in rats (Reich et al 1985, Brannstrom et al 1988, Tsafriri et al 1989, Butler et al 1991. Also, the activities of plasminogen activator and MMPs, including interstitial collagenase, type IV collagenase, gelatinase and proteoglycanase, increases during the periovulatory period (Palotie et al 1987, Curry et al 1992.…”

“…It is generally believed that remodeling of extracellular matrix involves at least two important enzyme systems, the matrix metalloproteinase (MMP) system and the serine proteinase plasminogen activator system (Seller & Murphy 1981, Harris et al 1984, Saksela 1985, Matrisian 1990). These proteinases have been shown to play important roles in the ovulatory process (Reich et al 1985, Palotie et al 1987, Brannstrom et al 1988, Tsafriri et al 1989, Butler et al 1991, Curry et al 1992.…”