inosine-triphosphate and Scleroderma--Systemic

Scleroderma patients exhibit increased chromosomal instability due to circulating clastogenic plasma factors (CF). Formation and action mechanisms of CF are mediated by superoxide. In addition, previous work detected inosine triphosphate (ITP) in the plasma of 2 patients, and the enzyme adenosine deaminase (ADA) was found to be increased.. To study correlations between CF, ITP and ADA levels, CF and disease activity, as well as other biomarkers of oxidative stress.. Clastogenic activity was evaluated by means of cytogenetic methods in 48 patients and 55 healthy subjects. ITP was detected by mass spectrometry and electrospray ionisation. ADA was measured with a colorimetric assay and malondialdehyde using the Yagi method.. Clastogenic activity was significantly increased in patients' plasma compared to controls. In 10 patients CF, ITP and ADA were studied simultaneously. All three parameters were increased in the 7 patients of subgroups 2 (skin and esophagus involvement) and 3 (skin plus multiple organ involvement). ITP was not detected in 2 patients of subgroup 1 (skin involvement only) with low ADA and CF values.. ITP, the deamination product of ATP, is one of the clastogenic and superoxide generating components of CF. The formation of this deamination product of ATP is probably related to the increase in ADA. CF are biomarkers of oxidative stress and can be used for evaluation of antioxidant treatments in scleroderma.

Topics: Adenosine Deaminase; Adult; Aged; Antioxidants; Biomarkers; Colorimetry; Electrochemistry; Esophageal Diseases; Female; Humans; Inosine Triphosphate; Lipid Peroxidation; Male; Malondialdehyde; Mass Spectrometry; Middle Aged; Mutagens; Oxidative Stress; Scleroderma, Systemic; Skin Diseases; Superoxide Dismutase; Superoxides

In the present study, we attempted to identify the chemical nature of the clastogenic factor (CF) from patients with progressive systemic sclerosis (scleroderma). Computerized mass spectrometry of clastogenic fractions obtained by HPLC of plasma ultrafiltrates detected molecular peaks compatible with inosine triphosphate and inosine diphosphate (ITP and IDP). The concomitant detection of IDP, together with ITP, and the absence of these peaks in nonclastogenic fractions and corresponding control fractions are arguments in favor of a biological relevance of these observations. The most important confirmation came from the clastogenic effect of commercial ITP and IDP added to the culture medium of the test cultures. The induction of chromatid type damage by these substances in lymphocytes exposed in the G0 phase of their cell cycle and the prevention of this damage by superoxide dismutase are analogous to the observations with CF.

Topics: Cells, Cultured; Chromatography, High Pressure Liquid; Chromosome Aberrations; Humans; Inosine Diphosphate; Inosine Nucleotides; Inosine Triphosphate; Lymphocytes; Mass Spectrometry; Mutagens; Reference Values; Ribonucleotides; Scleroderma, Systemic; Sister Chromatid Exchange; Superoxide Dismutase