Anti-Inflammatory Effects of Ergotamine in Steers (44562):

The objective of this experiment was to investigate whether the ergot alka- loid, 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), ergotamine (ET), endotoxin (LPS), and ET + LPS. ET and ET + LPS groups received a single bolus intravenous injection of ET (40 µg ? kg ? body wt ˛1 ), whereas C and LPS steers received a single bolus injection of sterile vehicle. Thirty minutes after ET/vehicle administration, a single bolus intrave- nous injection of LPS (0.2 µg ? kg ? body wt ˛1 ) was given. Blood was collected at various time points for 48 hr post. Endotoxin increased rectal temperature (RT) and the circulating levels of tumor necrosis factor-a (TNF-a), cortisol, haptoglobin (Hp), thromboxane B2 (TXB2). The circulating Hp, TNF-a, and TXB2 increases were blunted by pretreatment with ET compared with ET + LPS. Ergotamine by itself increased circulating cortisol and RT, whereas it decreased serum prolactin (PRL). Therefore, whereas administration of LPS at 0.2 µg/kg to steers resulted in an expected response, the combination of ET + LPS attenuated major effects of LPS alone. Thus, acute administration of ET appeared to be anti-inflammatory as it decreased the inflamma- tory response to LPS, an effect likely driven at least in part by the ET-caused cortisol increase. (P.S.E.B.M. 2000, Vol 225:136-142)