Acute heat stress and dietary methionine effects on IGF-I, GHR, and UCP mRNA expression in liver and muscle of quails

Abstract

ABSTRACT. This study evaluated the expression of insulin-like growth factor I (IGF-I), growth hormone receptor (GHR), and uncoupling protein (UCP) mRNA in muscle and liver of quails that were in thermal comfort or exposed to heat stress and that were fed diets with or without methionine supplementation. Meat quails were fed a diet that either met the nutritional demands for methionine (MS) or did not meet this demand (methioninedeficient diet, MD). The animals were either kept at a thermal comfort temperature (25°C) or exposed to heat stress (38°C for 24 h starting on the 6th day). RNA was extracted from liver and breast muscle, and cDNA was synthesized and amplified using quantitative reverse transcriptionpolymerase chain reaction. Animals that were fed the MS diet and remained at the thermal comfort temperature exhibited increased IGF-I mRNA 7295 Heat stress and methionine supplementation ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 13 (3): 7294-7303 (2014) expression in the liver (0.56 AU). The GHR mRNA expression in the liver and muscle was influenced by both the study variables. Animals receiving the MS diet showed higher GHR expression, while increased expression was observed in animals at the thermal comfort temperature. The UCP mRNA expression in the muscle was influenced by both methionine supplementation and heat stress. Higher expression was observed in animals that received the MD diet (2.29 vs 3.77 AU) and in animals kept in thermal comfort. Our results suggest that heat stress negatively affects the expression of growth-related genes and that methionine supplementation is necessary to appropriately maintain the levels of IGF-I, GHR, and UCP transcripts for animal metabolism.

Effects of Transport Duration and Environmental Conditions in Winter or Summer on the Concentrations of Insulin-Like Growth Factors and Insulin-Like Growth Factor-Binding Proteins in the Plasma of Market-Weight Pigs

“…This means, the body temperature is not constant but varies with water temperature which may have direct effects on metabolic and endocrine parameters in contrast to endothermic mammals. Contrary to the results of the fish study ( 32 ), IGF-II level variation was not inversely proportional to that in ambient temperature in the present study, probably due to the potential negative effect of heat stress on the expression of growth-related genes ( 37 ). It has been also suggested that potential environmental effects on IGF-system in market pigs are strongly dependent on the farm management system.…”

A comparison of two sources of methionine supplemented at different levels on heat shock protein 70 expression and oxidative stress product of Peking ducks subjected to heat stress

“…Thus, when the cell or organism succumbed to a non‐fatal stress response, HSP70 over‐expression may protect them from injury. In addition, it is reported that heat stress negatively affected the expression of growth‐related genes and that Met supplementation was necessary to appropriately maintain the levels of insulin‐like growth factor I (IGF‐I) and growth hormone receptor (Del Vesco, Gasparino, Zancanela, Grieser, Guimaraes et al., ). Wang et al.…”

Short‐term methionine supplementation during the early post‐partum period in primiparous rabbits improves prolificacy associated with an increase in serum concentrations of IGF‐I

“…Hepatic IGF‐I synthesis depends on the action of growth hormone (GH) in the liver through binding to the GH receptor (Guzmán et al., ). In broilers, methionine supplementation increases the mRNA expression of the GH receptor in the liver (Del Vesco et al., ), whereas in quail livers, the GH receptor mRNA expression is greater in animals that are supplemented with methionine than in animals that have methionine restriction (Del Vesco et al., ). Therefore, methionine likely increases the synthesis of the GH receptor in the liver, which then promotes IGF‐I synthesis and increases the level of this growth factor in the blood.…”