Expression profiles of carnosine synthesis–related genes in mice after ingestion of carnosine or ß-alanine

BACKGROUND Carnosine is a dipeptide that improves exercise performance. The carnosine synthesis mechanism through carnosine and ß-alanine ingestion remains unclear. Therefore, we investigated the tissue distribution of carnosine synthase, ATP-grasp domain-containing protein-1 (ATPGD1) mRNA, and ATPGD1 and carnosine specific dipeptidase (CN1) gene expression profiles in mice that were given carnosine or ß-alanine orally. METHODS ddY mice (7-week-old) were randomly divided into three groups (n = 6 to 8 animals per group) and were orally given 2 g/kg body weight of carnosine, ß-alanine, or water. After 15, 30, 60, 120, 180, or 360 min of treatment, the tissues (brain, blood, liver, kidneys, olfactory bulbs, hindleg muscles) were collected. The obtained tissues measured the expression of ATPGD1 and CN1 genes using quantitative PCR methods. RESULTS The ATPGD1 gene was expressed in muscle and to a lesser extent in brain. The expression of ATPGD1 in the vastus lateralis muscle increased significantly at 180 min (P = 0.023) after carnosine ingestion and 60 (P = 0.023) and 180 min (P = 0.025) after ß-alanine ingestion. Moreover, the carnosine group showed a significantly increased renal expression of the CN1 gene 60 min after ingestion (P = 0.0015). CONCLUSIONS The ATPGD1 gene showed high expression levels in brain and muscle. The ß-alanine or carnosine administration significantly increased ATPGD1 and CN1 expression in mice.