Novel immunoassay for TSH measurement in rats

Autor(es)

Alves, Thalita G. ^{[1, 2]} ; Melo, Maria Clara de C. ^{[1, 3]} ; Kasamatsu, Teresa S. ^[1] ; Oliveira, Kelen C. ^[1] ; de Souza, Janaina Sena ^[1] ; da Conceicao, Rodrigo Rodrigues ^[1] ; Giannocco, Gisele ^{[1, 4]} ; Dias-da-Silva, Magnus R. ^[1] ; Chiamolera, Maria Izabel ^{[1, 3]} ; Vieira, Jose Gilberto ^{[1, 3]}

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo Unifesp, Lab Endocrinol Mol & Translac, Div Endocrinol, Dept Med, Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Escola Paulista Med, Dept Bioquim, Div Biol Mol, Sao Paulo, SP - Brazil

^[3] Grp Fleury, Sao Paulo, SP - Brazil

^[4] Unifesp, Dept Ciencias Biol, Diadema, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ARCHIVES OF ENDOCRINOLOGY METABOLISM; v. 61, n. 5, p. 460-463, SEP-OCT 2017.
• Citações Web of Science: 0

Resumo

ABSTRACT Measuring thyroid hormones is an important aspect for the study of metabolism and for monitoring diseases in both human and animal models. The traditional method for hormone measurement in rats is the radioimmunoassay (RIA). However, the RIA is associated with some practical disadvantages, including the use of radioactive material, the need for specialized equipment and expert staff, the short shelf-life of kits according to the half-life of the radioisotope and high costs. The objective of this study was to develop a new cost-effective method for measuring TSH levels in rats that avoids the use of radioactive material. We developed an in-house competitive immunoassay using a reference standard, polyclonal antibody produced in rabbits and biotinylated antigen. This method was tested in 64 Wistar rats that were divided into a control group (n = 41) and a group with hypothyroidism (n = 23). Our assay demonstrated an analytical sensitivity of 0.24 ng/mL (n = 12) and an intra-assay coefficient of variation (CV) of 8.9% for sera with TSH levels of 1.5 ng/mL and 13.2% for sera with TSH levels of 17.5 ng/mL (n = 14). The inter-assay CV was 13.5% for sera with TSH levels of 1.4 ng/mL and 14.5% for TSH levels of 18.2 ng/mL (n = 5). The analysis of mean TSH levels in control rats (5.06 ± 0.5701) and hypothyroid rats (51.09 ± 5.136) revealed a statistically significant difference (p < 0.001) between the groups. This method showed good sensitivity, can be automated and is low-cost compared with RIA. Our method offers a viable alternative for TSH measurement in rats. (AU)

• Processo FAPESP: 13/26851-7 - Estudo in vivo do efeito dos desreguladores endócrinos glifosato e bisfenol-A sobre o eixo hipotálamo-hipófise-tiroide
• Beneficiário: Maria Izabel Chiamolera
• Modalidade de apoio: Auxílio à Pesquisa - Regular