| Abstract | Pancreatic preservation is an important part of diabetes management that may occur with improved peripheral insulin sensitivity and attenuated low-grade adipose tissue inflammation. The objective of the current study was to determine the response of obese, insulin-resistant fa/fa Zucker rats vs lean controls to dietary conjugated linoleic acid (CLA) supplementation with respect to pancreatic islet size, insulin resistance, and markers of inflammation and adipose glucose uptake. Six-week-old fa/fa and lean Zucker rats (n = 20 per genotype) were fed either a 1.5% CLA mixture or control diet for 8 weeks. Oral glucose tolerance testing was conducted at 7.5 weeks. Fasting serum haptoglobin, insulin, and C-peptide were assayed, and select messenger RNA (mRNA) and protein markers of inflammation and glucose metabolism were measured in adipose and liver tissues. CLA-fed fa/fa Zucker rats had smaller islet cell size, improved oral glucose tolerance and insulinemia, and attenuated serum haptoglobin levels compared with control-fed fa/fa Zucker rats, despite no differences in body weight and a slightly higher visceral adipose mass. CLA did not alter insulin sensitivity or islet size in lean Zucker rats. The CLA-fed fa/fa rats also had greater adipose glucose transporter-4 mRNA and less adipose tumor necrosis factor alpha mRNA and protein compared with control-fed fa/fa rats. In contrast, other markers of inflammation and glucose metabolism including adipose macrophage inflammatory factor, macrophage inflammatory protein-2, and liver pyruvate carboxylase and pyruvate dehydrogenase kinase 4 were not significantly changed. These results suggest that CLA supplementation preserved pancreatic function in conjunction with improved peripheral glucose use and reduced inflammation in fa/fa Zucker rats. |
| Authors | Amy Noto, Peter Zahradka, Natasha R Ryz, Natalia Yurkova, Xueping Xie, Carla G Taylor
(Affiliation: Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.)
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| Journal | Metabolism: clinical and experimental
(Metabolism)
Vol. 56
Issue 1
Pg. 142-51
(Jan 2007)
ISSN: 0026-0495 United States |
| PMID | 17161237
(Publication Type: Journal Article, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)
|
| Chemical References |
- Dietary Fats, Unsaturated
- Haptoglobins
- Linoleic Acids, Conjugated
- Insulin
- C-Reactive Protein
- Protein Kinases
- Protein-Serine-Threonine Kinases
- pyruvate dehydrogenase (acetyl-transferring) kinase
- Pyruvate Carboxylase
|
| Topics |
- Adipose Tissue
(metabolism)
- Animals
- Blotting, Western
- C-Reactive Protein
(metabolism)
- Dietary Fats, Unsaturated
(administration & dosage)
- Glucose Tolerance Test
- Haptoglobins
(metabolism)
- Insulin
(blood)
- Insulin Resistance
(physiology)
- Insulin-Secreting Cells
(cytology, metabolism)
- Linoleic Acids, Conjugated
(administration & dosage)
- Liver
(enzymology, metabolism)
- Organ Size
(drug effects, physiology)
- Pancreas
(anatomy & histology, metabolism)
- Protein Kinases
(genetics, metabolism)
- Protein-Serine-Threonine Kinases
- Pyruvate Carboxylase
(genetics, metabolism)
- Rats
- Rats, Zucker
- Reverse Transcriptase Polymerase Chain Reaction
|
