TY - JOUR
T1 - Unveiling the metabolic effects of glycomacropeptide
AU - Pena, Maria João
AU - Costa, Raquel
AU - Rodrigues, Ilda
AU - Martins, Sandra
AU - Guimarães, João Tiago
AU - Faria, Ana
AU - Calhau, Conceição
AU - Rocha, Júlio César
AU - Borges, Nuno
N1 - Funding Information:
Funding: This article was funded by the project NORTE-08-5369-FSE-000018, supported by Norte Portugal Regional Programme (Norte2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and by FCT—Fundação para a Ciência e a Tecnologia [UID/BIM/04293/2013].
Funding Information:
Acknowledgments: M.J.P. was partially funded by the project NORTE-08-5369-FSE-000018, supported by Norte Portugal Regional Programme (Norte2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Glycaemia strips and device were kindly provided by Abbott Laboratórios Lda., Portugal. A special thanks to Raquel Soares for the help submitting the project to the national authorities. Furthermore, thanks to Patrícia Ribeiro, Veterinary Nurse Adriana Francisco and Liliana Leite from the animal facilities.
Funding Information:
This article was funded by the project NORTE-08-5369-FSE-000018, supported by Norte Portugal Regional Programme (Norte2020), under the PORTUGAL 2020 Partnership Agreement,M.J.P. was partially funded by the project NORTE-08-5369-FSE-000018, supported by Norte Portugal Regional Programme (Norte2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). Glycaemia strips and device were kindly provided by Abbott Laborat?rios Lda., Portugal. A special thanks to Raquel Soares for the help submitting the project to the national authorities. Furthermore, thanks to Patr?cia Ribeiro, Veterinary Nurse Adriana Francisco and Liliana Leite from the animal facilities. through the European Regional Development Fund (ERDF) and by FCT?Funda??o para a Ci?ncia e a Tecnologia [UID/BIM/04293/2013].
Publisher Copyright:
© 2021 by the authors. Li-censee MDPI, Basel, Switzerland.
PY - 2021/9
Y1 - 2021/9
N2 - 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, n = 8), fAA (n = 8) or GMP (n = 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 tri-glycerides were seen both in fAA and GMP related to CAS. GMP also reduced albumin and triglyc-erides 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 mech-anisms.
AB - 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, n = 8), fAA (n = 8) or GMP (n = 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 tri-glycerides were seen both in fAA and GMP related to CAS. GMP also reduced albumin and triglyc-erides 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 mech-anisms.
KW - Amino acids
KW - GLP-1
KW - Glycomacropeptide
KW - Intact protein
KW - Metabolism
KW - Phenylketonuria
UR - http://www.scopus.com/inward/record.url?scp=85114368892&partnerID=8YFLogxK
U2 - 10.3390/ijms22189731
DO - 10.3390/ijms22189731
M3 - Article
C2 - 34575895
AN - SCOPUS:85114368892
SN - 1661-6596
VL - 22
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 18
M1 - 9731
ER -