Transport of β‐alanine and biosynthesis of carnosine by skeletal muscle cells in primary culture

Abstract

Uptake of β‐alanine and synthesis of carnosine (β‐alanyl‐histidine) could be demonstrated in primary cell cultures derived from embryonic chick pectoral muscle. Concomitant with the morphological changes, cessation of cell division and the induction of creatine kinase, a rapid increase in the rate of β‐alanine uptake and also in the rate of carnosine synthesis could be observed. The uptake of β‐alanine is sodium and chloride dependent and obeys Michaelis‐Menten kinetics with Km values of about 40 μM that are essentially identical for myoblasts and myotubes. In contrast, Vmax increases considerably during differentiation. The β‐alanine transport system is highly specific for β‐amino acids and exhibits a substantial anion dependency (Cl‐ > J‐ > CSN‐ > SO2‐4). Stoichiometric studies suggest that the transport of one β‐alanine molecule involves two sodium ions and one chloride ion. This ratio is not altered by the process of cell differentiation. Copyright © 1994, Wiley Blackwell. All rights reserved