ABSTRACT
Since oxypurines, e.g., xanthines and hypoxanthine, are intermediate metabolites in purine metabolism, the determination of these compounds in physiological samples provides important information on the malfunctioning of purine metabolism. Several methods for the determination of oxypurines in biological samples have been developed. The identification of these compounds was achieved by the method of direct introduction of a lyophilized sample of blood and muscle into a mass spectrometer. Hypoxanthine and xanthine are intermediate metabolites in purine nucleotide degradation. Disorders of purine metabolism have been known mainly in relation to the hereditary deficiency of certain enzymes in the purine metabolic pathway. Adenosine deaminase deficiency in association with severe combined immunodeficiency disease involving disorders of thymus-dependent and thymus-independent lymphocyte function is found in children.
