Abstract
Pyridinoline (PYR) and deoxypyridinoline (DP YR) promiss to be more excellent bone resorption markers than hydroxyproline, because they are only present in mature collagen, their major sources are bone and cartilage, and their excretion in urine is not influenced by the degradation of newly synthesized collagen molecules or noncollagenous protein. Therefore, a quantitative method was developed for the determination of PYR and DPYR cross-links of collagen in urine. Using this method, the inherent fluorescence of PYR and DPYR was detected using a high-performance liquid chromatography. The values of PYR and DPYR are given as equivalent amounts of pyridoxamine because there are no authorized standards, and are expressed as pmol/μmol creatinine. The mean values±SD of PYR and DPYR in urine from 26 healthy adults (13 males, 24-56 years old; 13 females, 23-31 years old) were 4.50±1.03 and 1.09±0.28, respectively. The PYR and DPYR excretion levels of a patient with hypothyroidism were similar to those of healthy adults, but those of two patients with hyperthyroidism were significantly higher. In cases of patients with bone metastases of malignant tumors, significantly higher levels of PYR and DPYR were detected in the urine.
