Studie zum Vorkommen von Prion Proteinen in Euter und Milch

In the present study expression apathogenic, cellular prion protein (PrPc) in the mammary gland of cattle, sheep and goat was assayed, as well as the content of respective protein in milk derived from above mentioned species. It could be shown that udder-related PrPc expression is species-specific. Furthermore, PrPc content in milk was obviously different. For sheep the dependence of secretion activity from the state of lactation could be displayed. The second part of the paper focused on the potential occurrence of pathogenic PrP isoform (PrPsc) in mammary gland and milk. As for cattle, neither expression nor secretion could be demonstrated. On the other hand, colostrum of either BSE or scrapie infected sheep reacted positively in ELISA. But results could not unequivocally be confirmed by western-blot. Thus, presence of PrPsc in milk derived from cows seems to be rather unlikely. On the other hand presence of respective protein in milk of scrapie-affected sheep can not completely be ruled out