Ovarian expression of a disintegrin and metalloproteinase with thrombospondin motifs during ovulation in the gonadotropin-primed immature rat

Mammalian ovulation is a dynamic process that requires degradation of the c ollagenous connective tissue in the thecal layers of a mature follicle. In this reverse transcription-polymerase chain reaction differential display s tudy, gonadotropin-primed immature rats were used to detect ovarian express ion of a relatively new type of disintegrin and metalloproteinase with thro mbospondin motifs (ADAMTS-1) that is known to cleave extracellular matrix i n acutely inflamed tissues. Immature Wistar rats were primed with 10 IU eCG s.c., and the temporal pattern of expression of the ADAMTS-1 gene was deli neated by extracting ovarian RNA at 0, 2, 4, 8, 12, and 24 h after inductio n of ovulation by injecting the primed animals with 10 IU hCG s.c, The diff erential display data, Northern analyses, and in situ hybridization microgr aphs all showed significant up-regulation of ADAMTS-1 gene expression by 8 h after hCG administration. The in situ data indicated that the ADAMTS-1 mR NA was in the granulosa layer of mature follicles. Expression reached a pea k at 12 h and remained elevated at 24 h after hCG. ADAMTS-1 gene expression was impaired by the antiprogesterone agent epostane, but this inhibition c ould be overcome by exogenous progesterone. ADAMTS-1 expression was not aff ected when ovulation was blocked by treatment of the animals with the anti- eicosanoid agent indomethacin, in conclusion, the temporal pattern of expre ssion of this gene, and its apparent regulation by progesterone, suggests t hat ADAMTS-1 has a significant role in the inflammatory events of the ovula tory process.