Potential leukocyte attractants in the bovine peri-ovulatory ovary

Abstract

― This study investigated interrelationships between the bovine ovarian cycle and white blood cells and tested the hypothesis that the ovary produces collagen-like materials with leukocyte attrac- tant activity. We examined the in vitro secretion of leukocyte attractant activity by peri-ovulatory ovar- ian tissues and evaluated the leukocyte attractant potential of some ovarian biochemicals. Fluid from mature ovarian follicles and medium conditioned by follicular tissue, early luteal tissue or granulosa cells had significant attractant activity. The activity could be removed by protein precipitation but not by collagenase. Collagenase also failed to alter the electrophoretic profile of the samples. Collagenase (800 IU/ml), ascorbic acid (10-1 000 pg/ml) and CaCl 2 (50-560 pg/ml) had significant leukocyte attrac- tant effects. Native collagen types I and IV (100-1 000 wg/ml) had fewer expressed attractant activities, which were unaffected by collagenase pre-treatment. The attractant activity of collagenase itself was removed by protein precipitation. Our observations suggest: (1) that follicular and luteal tissues produce leukocyte attractant(s); (2) that granulosa cells contribute to the secretion of this material; (3) that the principal ovarian attractants are neither the native collagen types I or IV nor their collagenase-releasable fragments; and (4) that collagenase, ascorbic acid and Ca 2 + are strong candidates as attractant con- stituents of ovarian secretions. bovine ovary / follicular fluid / polymorphonuclear leukocyte / collagenase / ascorbic acid / calcium / granulosa Rsum ― Substances leuco-attractives potentielles dans l'ovaire pri-ovulatoire bovin. Cette tude porte sur les relations possibles entre le cycle ovarien et les globules blancs. Notre hypothse de travail est que l'ovaire produit des substances attractives pour les leucocytes. Nous avons examin la scrtion in vitro de substances attractives par des tissus ovariens pri-ovulatoires. Le fluide de follicules murs et du milieu conditionn par du tissu folliculaire, du tissu de corps jaune ou des cellules de la granulosa ont une activit attractive significative. L'activit est limine par la prcipitation des protines mais non par la coliagnase. La collagnase ne modifie pas le profil lectrophortique des chantillons. La collagnase (800 lg/ml), l'acide ascorbique (10-1 000 > 9 /ml) et le chlorure de calcium * Present address: Research Institute of Animal Production, Hlohovsk 2, 949 92 Nitra, Slovakia (56-560 gglmo ont des effets attractifs significatifs. Le collagne natif de type 1 et IV (100-1 000 > 9 /ml) montre des niveaux d'activit infrieurs, non modifis par un prtraitement la collagnase. L'ac- tivit attractive de la collagnase est supprime par la prcipitation des protines. Nos observations suggrent que : i) les tissus folliculaires et lutaux produisent des substances leuco-attractives ; ii) les cel- lules de la granulosa contribuent leur scrtion ; iii) les principaux attractifs ovariens ne sont ni le collagne type 1 ou IV, ni leurs fragments produits par la collagnase ; iv) la collagnase, l'acide ascor- bique et Ca 2 + seraient des substances attractives des tissus ovariens. ovaire bovin / liquide folliculaire / lymphocyte / polymorphonuclaire / collagnase / acide ascorbique / calcium / granulosa