Influence of intra-abomasal administration of L-DOPA on circulating catecholamines and feed intake in cattle

Dopamine has multiple physiological functions including feed intake control in which it can act as an anorectic or orexigenic agent. This study had the objective to evaluate intra-abomasal administration of L-DOPA (levodopa; L-3,4-dihydroxyphenylalanine) from - Mucuna pruriens on circulating catecholamines, indicators energy metabolism and cattle. Eight Holstein steers (340 ± 20 kg) fitted with ruminal cannula were used a replicated 4 x Latin Square design experiment. Intra-abomasal infusion at 0, 0.5, 1 2 mg/kg BW was carried out for seven days blood samples collected 30, 60, 120, 240 480 min day 7. The area under curve (AUC) plasma free dopamine increased quadratically L-DOPA. However, AUC total positive linear response increase Conversely, serum 5-hydroxytriptophan (5-HTP), serotonin, tyrosine, glucose fatty acids not affected by concentration epinephrine, norepinephrine, did change infusion. It be concluded that produced strong no metabolites