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Leucine supplementation improves leptin sensitivity in high-fat diet fed rats.

Yuan XW, Han SF, Zhang JW, Xu JY, Qin LQ - Food Nutr Res (2015)

Bottom Line: No significant differences in body weight and food/energy intake existed among the four groups.These phenomena suggested that leptin sensitivity was improved in the leucine groups.Furthermore, the expressions of JAK2 and STAT3 (activated by ObR) were significantly higher, and that of SOCS3 (inhibits leptin signaling) was significantly lower in the three leucine groups than in the control group.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China.

ABSTRACT

Background: Several studies have reported the favorable effect of leucine supplementation on insulin resistance or insulin sensitivity. However, whether or not leucine supplementation improves leptin sensitivity remains unclear.

Design: Forty-eight male Sprague-Dawley rats were fed with either a high-fat diet (HFD) or HFD supplemented with 1.5, 3.0, and 4.5% leucine for 16 weeks. At the end of the experiment, serum leptin level was measured by ELISA, and leptin receptor (ObR) in the hypothalamus was examined by immunohistochemistry. The protein expressions of ObR and leptin-signaling pathway in adipose tissues were detected by western blot.

Results: No significant differences in body weight and food/energy intake existed among the four groups. Serum leptin levels were significantly lower, and ObR expression in the hypothalamus and adipose tissues was significantly higher in the three leucine groups than in the control group. These phenomena suggested that leptin sensitivity was improved in the leucine groups. Furthermore, the expressions of JAK2 and STAT3 (activated by ObR) were significantly higher, and that of SOCS3 (inhibits leptin signaling) was significantly lower in the three leucine groups than in the control group.

Conclusions: Leucine supplementation improves leptin sensitivity in rats on HFD likely by promoting leptin signaling.

No MeSH data available.


Related in: MedlinePlus

Serum leptin levels in the four groups at the end of the experiment. Values are means for 12 rats with SD represented by vertical bars. The mean value was significantly different from that of the HFD group at ##P<0.01. HFD, high-food diet; Leu, leucine.
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Figure 0002: Serum leptin levels in the four groups at the end of the experiment. Values are means for 12 rats with SD represented by vertical bars. The mean value was significantly different from that of the HFD group at ##P<0.01. HFD, high-food diet; Leu, leucine.

Mentions: At the end of the experiment, the serum levels of leptin were 2.31±0.23 ng/mL, 1.69±0.26 ng/mL, 1.87±0.27 ng/mL, and 1.91±0.29 ng/mL in the HFD, HFD+1.5% Leu, HFD+3.0% Leu, and HFD+4.5% Leu groups, respectively. The serum leptin level was significantly lower in the three leucine groups than in the HFD group (all P<0.01; Fig. 2). The leptin level in the HFD+1.5% Leu group was the lowest, but there were no significant differences among the three leucine groups.


Leucine supplementation improves leptin sensitivity in high-fat diet fed rats.

Yuan XW, Han SF, Zhang JW, Xu JY, Qin LQ - Food Nutr Res (2015)

Serum leptin levels in the four groups at the end of the experiment. Values are means for 12 rats with SD represented by vertical bars. The mean value was significantly different from that of the HFD group at ##P<0.01. HFD, high-food diet; Leu, leucine.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4482813&req=5

Figure 0002: Serum leptin levels in the four groups at the end of the experiment. Values are means for 12 rats with SD represented by vertical bars. The mean value was significantly different from that of the HFD group at ##P<0.01. HFD, high-food diet; Leu, leucine.
Mentions: At the end of the experiment, the serum levels of leptin were 2.31±0.23 ng/mL, 1.69±0.26 ng/mL, 1.87±0.27 ng/mL, and 1.91±0.29 ng/mL in the HFD, HFD+1.5% Leu, HFD+3.0% Leu, and HFD+4.5% Leu groups, respectively. The serum leptin level was significantly lower in the three leucine groups than in the HFD group (all P<0.01; Fig. 2). The leptin level in the HFD+1.5% Leu group was the lowest, but there were no significant differences among the three leucine groups.

Bottom Line: No significant differences in body weight and food/energy intake existed among the four groups.These phenomena suggested that leptin sensitivity was improved in the leucine groups.Furthermore, the expressions of JAK2 and STAT3 (activated by ObR) were significantly higher, and that of SOCS3 (inhibits leptin signaling) was significantly lower in the three leucine groups than in the control group.

View Article: PubMed Central - PubMed

Affiliation: Department of Nutrition and Food Hygiene, School of Public Health, Soochow University, Suzhou, China.

ABSTRACT

Background: Several studies have reported the favorable effect of leucine supplementation on insulin resistance or insulin sensitivity. However, whether or not leucine supplementation improves leptin sensitivity remains unclear.

Design: Forty-eight male Sprague-Dawley rats were fed with either a high-fat diet (HFD) or HFD supplemented with 1.5, 3.0, and 4.5% leucine for 16 weeks. At the end of the experiment, serum leptin level was measured by ELISA, and leptin receptor (ObR) in the hypothalamus was examined by immunohistochemistry. The protein expressions of ObR and leptin-signaling pathway in adipose tissues were detected by western blot.

Results: No significant differences in body weight and food/energy intake existed among the four groups. Serum leptin levels were significantly lower, and ObR expression in the hypothalamus and adipose tissues was significantly higher in the three leucine groups than in the control group. These phenomena suggested that leptin sensitivity was improved in the leucine groups. Furthermore, the expressions of JAK2 and STAT3 (activated by ObR) were significantly higher, and that of SOCS3 (inhibits leptin signaling) was significantly lower in the three leucine groups than in the control group.

Conclusions: Leucine supplementation improves leptin sensitivity in rats on HFD likely by promoting leptin signaling.

No MeSH data available.


Related in: MedlinePlus