Interactions in sheep between tall fescue ergot alkaloids and hepatotoxic carbon tetrachloride and Senecio pyrrolizidine alkaloids.

The interaction between ergot alkaloids in endophyte-infected (E+) tall fescue (Festuca arundinacea) seed and pyrrolizidine alkaloids (PA) in tansy ragwort (TR; Senecio jacobaea) when simultaneously fed to sheep was investigated. Because of the hepatogenic effects of prolactin (PRL), it was hypothesized that low serum PRL induced by ergot alkaloids would increase the susceptibility of sheep to hepatotoxicity induced by PA. Sheep are normally resistant to PA-induced hepatotoxicity.