Data/hora: 12/06/2024 12:37:34

Provedor de dados: 	89	
País: 	Brazil	
Título: 	The Effect of Humic Acid Substances on the Thyroid Function and Structure in Lead Poisoning	
Autores: 	Sahin,A; Iskender,H; Terim,Kapakin KA; Altinkaynak,K; Hayirli,A; Gonultas,A; Kaynar,O.	
Data: 	2016-12-01	
Ano: 	2016	
Palavras-chave: 	Lead poisoning; Humic acid substances; Thyroid gland; Chicken.	
Resumo: 	ABSTRACT Lead (Pb) is a heavy metal, which adversely affects thyroid gland function and structure. Due to its high molecular weight and abundant functional groups, humic acid substances (HAS) can form chelates with heavy metals. The experiment was conducted to evaluate the prophylactic effect of HAS on thyroid hormone levels and histopathological lesions of laying hens exposed to lead (Pb) poisoning. After a week of adaptation, 192 Lohmann White laying hens (25 weeks of age) were fed one of four diets: a basal diet (BD) or the BD with HAS (0.15%), with Pb (0.3 g/kg), or with both. Experimental groups were replicated in 12 cages, with four hens each. Pb poisoning did not alter triiodothyronine (FT3; 3.22 ± 0.20 ng/dL) or thyroxine (FT4; 0.71 ± 0.08 ng/dL) concentrations, but caused a 167% increase in thyroid stimulating hormone (TSH) concentration. HAS supplementation returned the high TSH levels of hens exposed to Pb poisoning to normal values. Degenerative changes in the epithelial cells of the thyroid gland of the hens exposed to Pb poisoning were evidenced. Connective tissue cells in the interfollicular area and total amount of colloids with partially atrophic follicles were observed. These histopathological findings were less severe when HAS was added to the diet. In conclusion, HAS alleviates the effects of Pb poisoning on thyroid gland function and structure, possibly preventing its internalization by the tissue by forming chelates and exerting anti-inflammatory effects.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-635X2016000400649	
Editor: 	Fundação APINCO de Ciência e Tecnologia Avícolas	
Relação: 	10.1590/1806-9061-2016-0299	
Formato: 	text/html	
Fonte: 	Brazilian Journal of Poultry Science  v.18 n.4 2016	
Fonte: 	info:eu-repo/semantics/openAccess