Functions of the GABAergic system on serum LH concentrations in pre-pubertal Nellore heifers
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Data
2021-06-01
Autores
Cardoso, Daniel
Cardoso, Rodolfo C.
Nogueira, Guilherme de Paula [UNESP]
Título da Revista
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Editor
Elsevier B.V.
Resumo
This study was conducted to evaluate the luteinizing hormone (LH) secretion pattern after gamma-aminobutyric acid (GABA(A)) antagonist to determine the effects of the GABAergic system on LH secretion during reproductive maturation in pre-pubertal Nellore heifers. Nellore heifers (n = 10) were administered a picrotoxin injection of 0.18 mg/kg, i.v. Blood samples were collected every 15 min for 3 h at different developmental stages (8, 10, 14 and 17 mo of age). Plasma concentrations of LH were quantified using an RIA (sensitivity of 0.04 ng/mL and CV of 15 %). There was an interaction between treatment and age (P = 0.034). Picrotoxin-treated heifers had lesser (P <= 0.05) LH mean concentrations during a 3 h period at 10 and 17 mo of age compared to control heifers (P <= 0.05). Comparing the period before and after Picrotoxin injection in the same animals, there was a 33 % decrease in LH concentration at 8 mo of age (P = 0.0165). These results indicate the GABAergic system has a stimulatory function in inducing LH secretion in pre-pubertal Nellore heifers. These findings corroborate previous results that GABA increases GnRH/LH secretion in other species during the pre-pubertal period.
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Palavras-chave
Hypothalamus, Neuroendocrine, Picrotoxin, Puberty, Sexual maturation
Como citar
Animal Reproduction Science. Amsterdam: Elsevier, v. 229, 6 p., 2021.