Effect of Dietary Lead on Intestinal Nutrient Transporters mRNA Expression in Broiler Chickens

Abstract

Lead- (Pb-) induced oxidative stress is known to suppress growth performance and feed efficiency in broiler chickens. In an attempt to describe the specific underlying mechanisms of such phenomenon we carried out the current study. Ninety-six one-day-old broiler chicks were randomly assigned to 2 dietary treatment groups of 6 pen replicates, namely, (i) basal diet containing no lead supplement (control) and (ii) basal diet containing 200 mg lead acetate/kg of diet. Following 3 weeks of experimental period, jejunum samples were collected to examine the changes in gene expression of several nutrient transporters, antioxidant enzymes, and heat shock protein 70 (Hsp70) using quantitative real-time PCR. The results showed that addition of lead significantly decreased feed intake, body weight gain, and feed efficiency. Moreover, with the exception of GLUT5, the expression of all sugar, peptide, and amino acid transporters was significantly downregulated in the birds under Pb induced oxidative stress. Exposure to Pb also upregulated the antioxidant enzymes gene expression together with the downregulation of glutathione S-transferase and Hsp70. In conclusion, it appears that Pb-induced oxidative stress adversely suppresses feed efficiency and growth performance in chicken and the possible underlying mechanism for such phenomenon is downregulation of major nutrient transporter genes in small intestine.

Broiler Tavuklarda Aflatoksin ile Kontamine Diyette Ticari Toksin Bağlayıcı, Doğal Probiyotik Türleri, Maya Hücre Duvarı ve Aluminosilikatın GOT2 ve CYP450 1A5 Gen Ekspresyonları İle Karaciğer Enzimlerinin Serum Konsantrasyonları Üzerine Etkisi

“…K1621), according to the manufacturer instructions [18] . To carry out the quantitative RT-PCR, the volume of reaction was set on 25 uL, in which cDNA concentration and the final concentration of SYBR green were respectively set on 6.25 and 0.25 ng/μL [21] . In this study, β-actin was used as a housekeeping control that under these conditions Effect of Commercial Toxin ... no changes will occure in its expression levels [22] and PCR was designed for 80 cycles so that 15 sec at 94°C for Denaturation, 30 sec at 60°C for Annealing and 30 sec at 72°C for Elongation were intended.…”

“…The amount of ΔCT was obtained by subtracting the cycle threshold of sample from the amount of CT for β-actin gene. The group with the highest amount of ΔCT means it has the lowest gene expression [21] . The amount of ΔCT was calculated by Livak and Schmittgen method [25] .…”

Avian and Mammalian Facilitative Glucose Transporters

“…Chicken GLUT5 has been shown to have mRNA expression in the small intestine [33] and may be regulated by glucocorticoids [34].…”

“…For chicken studies, GLUT1 has been analyzed across various chicken tissues [19] and embryonic myoblasts [18] and fibroblasts [62]. GLUT2 was cloned by screening a chicken liver cDNA library [20] and examined for expression in various chicken tissues [34,1]. GLUT3 was examined across various chicken tissues [19,17,1].…”

“…GLUT3 was examined across various chicken tissues [19,17,1]. GLUT5 was examined for its presence in enterocytes and its mRNA expression pattern [33,34]. GLUT8 has been tested across various chicken tissues [1,2].…”