CONCENTRATION OF TISSUE INHIBITOR OF METALLOPROTEINASES (TIMP)-1 IN-OVINE FOLLICULAR-FLUID AND SERUM

Tissue inhibitor of metalloproteinases (TIMP)-1 mRNA and protein local ize within granulosal cells of post-gonadotropin-surge follicles and l uteal tissue in ewes. Our objectives were to test the hypotheses that 1) follicular fluid concentration of TIMP-1 increases following a gona dotropin surge induced by LHRH agonist (Exp. 1) and 2) luteal status a ffects peripheral serum concentration of TIMP-1 (Exp. 2 and 3). In Exp . 1, the concentration of TIMP-1 within antral fluid from post-surge f ollicles (28.7 +/- 6.65 mu g/mL) was greater (P < .02) than from pre-s urge follicles (2.37 +/- 2.47 mu g/mL). In Exp. 2, serum concentration of TIMP-1 did not differ among d 0 to 6 (1.27 +/- .55 mu g/mL) of the estrous cycle or among periods of luteal maintenance (1.29 +/- .06 mu g/mL), spontaneous luteal regression (1.19 +/- .09 mu g/mL), or lutea l development (1.22 +/- .08 mu g/mL). However, serum concentration of TIMP-1 was greater (P < .001) during the period of luteal maintenance (1.14 +/- .04 mu g/mL) mt) than during PGF(2 alpha)-induced luteolysis (d 26; .85 +/- .06 mu g/mL) and induced luteal absence (d 27 to 33; . 95 +/- .05 mu g/mL). In Exp. 3, ewes (n = 14) were bled daily from d 1 to 19 (d 0 = estrus) and at 12-min intervals for 6 h on d 3, 10, and 17. Although concentration of TIMP-1 varied considerably within and am ong ewes, mean concentration of TIMP-1 per ewe per day increased (P < .05) from d 3 to 17. These data indicate that follicular fluid concent ration of TIMP-1 increases following a gonadotropin surge, but the con tribution of ovarian derived TIMP-1 to peripheral serum concentration is negligible.