Time-dependent changes in plasma concentrations of 3-methylindole and blood concentrations of 3-methyleneindolenine-adduct in feedlot cattle

Abstract

Blood 3MEIN-adduct concentrations peaked during the period of greatest risk for development of bovine respiratory disease complex. Conversely, plasma 3MI concentrations decreased during the same period. Animal-to-animal variation in metabolic capacity to convert 3MI to 3MEIN may be of more importance than differences in plasma 3MI concentration.

Effects of feeding aspirin and supplemental vitamin E on plasma concentrations of 3-methylindole, 3-methyleneindolenine-adduct concentrations in blood and pulmonary tissues, lung lesions, and growth performance in feedlot cattle

“…Plasma concentrations of 3MI and 3MEIN concentrations in blood samples were negatively correlated in another study. 17 The reasons for the unexpected findings reported here were not clear, but it seems likely that differences in these concentrations were coincidental rather than being systematically associated with the treatments. …”

“…In another study, 17 3MEIN-adduct concentrations in blood samples were increased during the period typically associated with the greatest risk for BRDC, although plasma 3MI concentrations did not exceed basal concentrations. Therefore, increases in ruminal generation of 3MI or bioactivation in pulmonary tissues may increase the risk for BRDC in feedlot cattle.…”

Quantitative Analysis of Ethyl Carbamate in Distillers Grains Co-products and Bovine Plasma by Gas Chromatography–Mass Spectrometry

“…It is precipitated by the ruminal degradation of l -tryptophan, a common amino acid in lush forages and feed grains, to 3-methyl indole (3-MI). , It is absorbed, and in high enough concentrations, its metabolites cause damage to pulmonary alveolar cells and AIP can develop. In feedlot cattle being fed a high-grain diet, 3-MI has been targeted as the causative agent of feedlot AIP, but past research has demonstrated inconsistent results. , The amount of l -tryptophan in high-grain diets may not be high enough to create enough 3-MI to be toxic, leading the scientists to consider the cause of feedlot AIP to be multifactorial …”

“…In feedlot cattle being fed a high-grain diet, 3-MI has been targeted as the causative agent of feedlot AIP, but past research has demonstrated inconsistent results. 5,6 The amount of L-tryptophan in high-grain diets may not be high enough to create enough 3-MI to be toxic, leading the scientists to consider the cause of feedlot AIP to be multifactorial. 7 The formation of 3-MI toxic metabolites in pulmonary cells that leads to AIP is because of intracellular cytochrome P450 (CYP450) enzymes metabolizing 3-MI to 3-methyleneindoline .…”

Quantitative Analysis of Ethyl Carbamate in Distillers Grains Co-products and Bovine Plasma by GC-MS

“…It is absorbed, and in high enough concentrations its metabolites cause damage to pulmonary alveolar cells and AIP can develop. In feedlot cattle being fed a high grain diet 3-methyl indole has been targeted as the causative agent of feedlot AIP, but past research has demonstrated inconsistent results 5,6 . The amount of ltryptophan in high grain diets may not be high enough to create enough 3-MI to be toxic, leading the field to consider the cause of feedlot AIP to be multifactorial 7 .…”