L-Cycloserine regulates sphingolipide metabolism by inhibiting the key enzyme serine palmitoyltransferase. Both cycloserine enantiomers inhibit 3-ketodihydrosphingosine synthetase (EC 2.3.1.50), though the L-form is the more potent inhibitor of the enzyme. Pérez-Sala et al. studied its inhibitory activity on pyruvate metabolism.