ENDOCRINOLOGIC AND REPRODUCTIVE BIOLOGICA L CONSEQUENCES OF CERTAIN ENDOTOXIN-MEDIATED DISEASES IN FARM MAMMALS - REVIEW ARTICLE

After giving an overview of the general pathology of endotoxin mediate d diseases the authors summarize the endotoxin induced endocrine chang es and their clinical consequences, with particular regard to reproduc tion. Forced, premature leuteolysis with formation of short-lived corp ora lutea in cyclic non-pregnant individuals as well as with embryonal loss in the corpus luteum dependent phase of pregnancy might be attri buted to the temporary activation of cyclooxygenase-2 and lipoxygenase enzyme systems resulting in elevated release of various prostanoids ( Table) in ruminants, sows and mares. The clinical relevance of this ph enomenon, however, is strongly influenced by the species- dependent du ration of the prostaglandin F-2 alpha-insensitive period in the corpus luteum phase in cyclic animals and by the endocrine characteristics o f pregnancy in different species. Both the experimental administration of endotoxin and the natural out-break of an endotoxin mediated disea se (for example Gram-negative mastitis) are always followed by an abou t 24 h long elevation in peripheral level of glucocorticoids to which clinical importance is attributed in the down-regulation of certain in flammatory mediators, mainly of alpha-tumor necrosis factor. This incr eased cortisol level may interfere, however, also with the baseline an d preovulatory LH secretion resulting in alterations in the follicular growth. The clinical failures attributable to endotoxin induced chang es in thyroid function and in peripheral level of some other hormones (prolactin, growth hormone and insulin-like growth factor 1) are also reviewed shortly.