TY - JOUR
T1 - 5-Hydroxytryptophan strongly stimulates serotonin synthesis in Holstein steers
AU - Valente, E. E.L.
AU - Klotz, J. L.
AU - Harmon, D. L.
N1 - Publisher Copyright:
© 2020 Elsevier Inc.
PY - 2021/1
Y1 - 2021/1
N2 - Although serotonin has been extensively studied in many species, there is a lack of information in ruminants, and no research has been evaluated if its precursor, 5-hydroxytryptophan (5-HTP), administered into the abomasum may be used as a means to manipulate serotonin metabolism. Thus, the objective of this study was to evaluate if intra-abomasal infusion of 5-HTP increases circulating serotonin in the steer. Eight Holstein steers (471 ± 8.9 kg) were used in a replicated 4 × 4 Latin Square design experiment. The treatments were intra-abomasal infusion of 5-HTP at 0.5, 1, 2.5, and 5 mg/kg BW. Blood was collected at 0, 2, 4, 6, 8, and 24 h after infusion. The serum concentration of 5-HTP increased quadratically (P = 0.005) with a peak at 2 h after administration. The 5-HTP administration increased (P < 0.05) serum serotonin in comparison with baseline with no difference (P > 0.05) between the doses of 5-HTP. When 5-HTP was dosed at 2.5 mg/kg BW or higher, intake decreased, and there was an altered manure consistency. The serum 5-hydroxyindole acetic acid concentrations followed the same pattern as 5-HTP. Plasma glucose content was not affected (P > 0.05) by 5-HTP dosing. However, free fatty acids concentration in the plasma was lower (P > 0.05) compared with baseline for the infusion levels of 0.5 and 1 mg/kg BW. Intra-abomasal infusion of 5-HTP efficiently increases serum serotonin cattle.
AB - Although serotonin has been extensively studied in many species, there is a lack of information in ruminants, and no research has been evaluated if its precursor, 5-hydroxytryptophan (5-HTP), administered into the abomasum may be used as a means to manipulate serotonin metabolism. Thus, the objective of this study was to evaluate if intra-abomasal infusion of 5-HTP increases circulating serotonin in the steer. Eight Holstein steers (471 ± 8.9 kg) were used in a replicated 4 × 4 Latin Square design experiment. The treatments were intra-abomasal infusion of 5-HTP at 0.5, 1, 2.5, and 5 mg/kg BW. Blood was collected at 0, 2, 4, 6, 8, and 24 h after infusion. The serum concentration of 5-HTP increased quadratically (P = 0.005) with a peak at 2 h after administration. The 5-HTP administration increased (P < 0.05) serum serotonin in comparison with baseline with no difference (P > 0.05) between the doses of 5-HTP. When 5-HTP was dosed at 2.5 mg/kg BW or higher, intake decreased, and there was an altered manure consistency. The serum 5-hydroxyindole acetic acid concentrations followed the same pattern as 5-HTP. Plasma glucose content was not affected (P > 0.05) by 5-HTP dosing. However, free fatty acids concentration in the plasma was lower (P > 0.05) compared with baseline for the infusion levels of 0.5 and 1 mg/kg BW. Intra-abomasal infusion of 5-HTP efficiently increases serum serotonin cattle.
KW - 5-HT
KW - 5-HTP
KW - Cattle
KW - Neurotransmitter
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U2 - 10.1016/j.domaniend.2020.106560
DO - 10.1016/j.domaniend.2020.106560
M3 - Article
C2 - 33035847
AN - SCOPUS:85092181837
SN - 0739-7240
VL - 74
JO - Domestic Animal Endocrinology
JF - Domestic Animal Endocrinology
M1 - 106560
ER -