FEMALE PROTEIN, AMYLOIDOSIS, AND HORMONAL CARCINOGENESIS IN TURKISH HAMSTER - DIFFERENCES FROM SYRIAN-HAMSTER

The Syrian hamster (Mesocricetus auratus) has been widely used as an e xperimental animal and is a unique model for three sex hormone-regulat ed events: 1) estrogen-initiated renal carcinogenesis, 2) sex-limited expression of amyloidosis, a ubiquitous disease, and 3) sex hormone co ntrol of a serum amyloid P component (SAP) called female protein (FP). In this study, we evaluated the closely related Turkish hamster (Meso cricetus brandti) for these three events and found some very different responses: 1) estrogen-initiated renal carcinogenesis was not found i n Turkish hamster, 2) amyloidosis was not sex limited and actually was a rare disease in the Turkish hamster, and 3) Turkish hamsters did ex press a sex-limited SAP-FP in serum that was antigenically identical a nd structurally very similar (97.5%) to Syrian hamster SAP-FP. However , acute phase regulation of SAP-FP synthesis was different, and serum levels of this pentraxin were much lower than those found in the Syria n hamster. On the other hand, in contrast to findings in the Syrian ha mster, hepatic tumors were relatively common in normal and especially in estrogen-treated Turkish hamsters. Therefore, although they are clo sely related, these two Mesocricetus hamster species have markedly dis similar responses to sex hormones.