Anti-inflammatory effects of ergotamine in steers

The objective of this experiment was to Investigate whether the ergot alkal oid, ergotamine (ET), an alkaloid used to model fescue toxicosis in cattle, modifies the response of cattle to endotoxin (LPS) challenge. Steers (n = 16) were divided into the following treatment groups: control (C), ergotami ne (ET), endotoxin (LPS), and ET + LPS, ET and ET + LPS groups received a s ingle bolus intravenous injection of ET (40 mug . kg . body wt(-1)), wherea s C and LPS steers received a single bolus injection of sterile vehicle. Th irty minutes after ET/vehicle administration, a single bolus intravenous in jection of LPS (0.2 mug . kg . body wt(-1)) was given. Blood was collected at various time points for 48 hr post. Endotoxin increased rectal temperatu re (RT) and the circulating levels of tumor necrosis factor-alpha (TNF-alph a), cortisol, haptoglobin (Hp), thromboxane B-2 (TXB2), The circulating Hp, TNF-alpha, and TXB2 increases were blunted by pretreatment with ET compare d with ET + LPS. Ergotamine by itself increased circulating cortisol and RT , whereas it decreased serum prolactin (PRL). Therefore, whereas administra tion of LPS at 0.2 mug/kg to steers resulted in an expected response, the c ombination of ET + LPS attenuated major effects of LPS alone, Thus, acute a dministration of ET appeared to be anti-inflammatory as it decreased the in flammatory response to LPS, an effect likely driven at least in part by the ET-caused cortisol increase.