Unveiling the Metabolic Effects of Glycomacropeptide
For many years, the main nitrogen source for patients with phenylketonuria (PKU) was phenylalanine-free amino acid supplements. Recently, casein glycomacropeptide (GMP) supplements have been prescribed due to its functional and sensorial properties. Nevertheless, many doubts still persist about the...
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doaj-e3c3318154e74a368da69f904272a0742021-09-26T00:22:29ZengMDPI AGInternational Journal of Molecular Sciences1661-65961422-00672021-09-01229731973110.3390/ijms22189731Unveiling the Metabolic Effects of GlycomacropeptideMaria João Pena0Raquel Costa1Ilda Rodrigues2Sandra Martins3João Tiago Guimarães4Ana Faria5Conceição Calhau6Júlio César Rocha7Nuno Borges8Departamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, PortugalDepartamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, PortugalDepartamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, PortugalDepartment of Clinical Pathology, São João Hospital Centre, 4200-319 Porto, PortugalDepartamento de Biomedicina, Unidade de Bioquímica, Faculdade de Medicina, Universidade do Porto, 4200-319 Porto, PortugalNutrition & Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, 1169-056 Lisboa, PortugalNutrition & Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, 1169-056 Lisboa, PortugalNutrition & Metabolism, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, 1169-056 Lisboa, PortugalCINTESIS—Centre for Health Technology and Services Research, 4200-450 Porto, PortugalFor many years, the main nitrogen source for patients with phenylketonuria (PKU) was phenylalanine-free amino acid supplements. Recently, casein glycomacropeptide (GMP) supplements have been prescribed due to its functional and sensorial properties. Nevertheless, many doubts still persist about the metabolic effects of GMP compared to free amino acids (fAA) and intact proteins such as casein (CAS). We endeavour to compare, in rats, the metabolic effects of different nitrogen sources. Twenty-four male Wistar rats were fed equal energy density diets plus CAS (control, <i>n</i> = 8), fAA (<i>n</i> = 8) or GMP (<i>n</i> = 8) for 8 weeks. Food, liquid intake and body weight were measured weekly. Blood biochemical parameters and markers of glycidic metabolism were assessed. Glucagon-like peptide-1 (GLP-1) was analysed by ELISA and immunohistochemistry. Food intake was higher in rats fed CAS compared to fAA or GMP throughout the treatment period. Fluid intake was similar between rats fed fAA and GMP. Body weight was systematically lower in rats fed fAA and GMP compared to those fed CAS, and still, from week 4 onwards, there were differences between fAA and GMP. None of the treatments appeared to induce consistent changes in glycaemia, while insulin levels were significantly higher in GMP. Likewise, the production of GLP-1 was higher in rats fed GMP when compared to fAA. Decreased urea, total protein and triglycerides were seen both in fAA and GMP related to CAS. GMP also reduced albumin and triglycerides in comparison to CAS and fAA, respectively. The chronic consumption of the diets triggers different metabolic responses which may provide clues to further study potential underlying mechanisms.https://www.mdpi.com/1422-0067/22/18/9731glycomacropeptideamino acidsintact proteinmetabolismGLP-1phenylketonuria |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Maria João Pena Raquel Costa Ilda Rodrigues Sandra Martins João Tiago Guimarães Ana Faria Conceição Calhau Júlio César Rocha Nuno Borges |
spellingShingle |
Maria João Pena Raquel Costa Ilda Rodrigues Sandra Martins João Tiago Guimarães Ana Faria Conceição Calhau Júlio César Rocha Nuno Borges Unveiling the Metabolic Effects of Glycomacropeptide International Journal of Molecular Sciences glycomacropeptide amino acids intact protein metabolism GLP-1 phenylketonuria |
author_facet |
Maria João Pena Raquel Costa Ilda Rodrigues Sandra Martins João Tiago Guimarães Ana Faria Conceição Calhau Júlio César Rocha Nuno Borges |
author_sort |
Maria João Pena |
title |
Unveiling the Metabolic Effects of Glycomacropeptide |
title_short |
Unveiling the Metabolic Effects of Glycomacropeptide |
title_full |
Unveiling the Metabolic Effects of Glycomacropeptide |
title_fullStr |
Unveiling the Metabolic Effects of Glycomacropeptide |
title_full_unstemmed |
Unveiling the Metabolic Effects of Glycomacropeptide |
title_sort |
unveiling the metabolic effects of glycomacropeptide |
publisher |
MDPI AG |
series |
International Journal of Molecular Sciences |
issn |
1661-6596 1422-0067 |
publishDate |
2021-09-01 |
description |
For many years, the main nitrogen source for patients with phenylketonuria (PKU) was phenylalanine-free amino acid supplements. Recently, casein glycomacropeptide (GMP) supplements have been prescribed due to its functional and sensorial properties. Nevertheless, many doubts still persist about the metabolic effects of GMP compared to free amino acids (fAA) and intact proteins such as casein (CAS). We endeavour to compare, in rats, the metabolic effects of different nitrogen sources. Twenty-four male Wistar rats were fed equal energy density diets plus CAS (control, <i>n</i> = 8), fAA (<i>n</i> = 8) or GMP (<i>n</i> = 8) for 8 weeks. Food, liquid intake and body weight were measured weekly. Blood biochemical parameters and markers of glycidic metabolism were assessed. Glucagon-like peptide-1 (GLP-1) was analysed by ELISA and immunohistochemistry. Food intake was higher in rats fed CAS compared to fAA or GMP throughout the treatment period. Fluid intake was similar between rats fed fAA and GMP. Body weight was systematically lower in rats fed fAA and GMP compared to those fed CAS, and still, from week 4 onwards, there were differences between fAA and GMP. None of the treatments appeared to induce consistent changes in glycaemia, while insulin levels were significantly higher in GMP. Likewise, the production of GLP-1 was higher in rats fed GMP when compared to fAA. Decreased urea, total protein and triglycerides were seen both in fAA and GMP related to CAS. GMP also reduced albumin and triglycerides in comparison to CAS and fAA, respectively. The chronic consumption of the diets triggers different metabolic responses which may provide clues to further study potential underlying mechanisms. |
topic |
glycomacropeptide amino acids intact protein metabolism GLP-1 phenylketonuria |
url |
https://www.mdpi.com/1422-0067/22/18/9731 |
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