CIRCADIAN RHYTHMICITY OF PLASMA SOMATOSTATIN, GASTRIN AND CORTISOL INCOLON-CANCER PATIENTS

Background/Aims: The aim of the study was to compare somatostatin, gas trin and cortisol levels over a 24 hour period in patients suffering f rom large bowel cancer and to compare this group With healthy subjects and patients suffering from other large bowel diseases (ulcerative co litis, large bowel polyps). Materials and Methods: There were 11 cance r patients (8 men and 3 women). The plasma levels of somatostatin, gas trin, and cortisol were determined by radioimmunoassay. Fisher's perio dogram and Halberg's cosinor analysis were used for statistical evalua tion. Results: We confirmed 24-hour rhythm of somatostatin, gastrin an d cortisol secretion in patients with colon. cancer. The most importan t findings were a higher mesor (p < 0.01) of gastrin. compared to all other groups and a lower 24-hour amplitude (p < 0.05) and a shorter 12 -hour acrophase (p < 0.05) of cortisol compared to all other groups we re found. Conclusion: Chrono-abnormalities in gastrin, and cortisol se cretion may reflect the role of gastrin in the etiopathogenesis of col on cancer and a reduced responsiveness to stimulus in patients with ma lignant diseases. Somatostatin blood levels probably do not reflect it s antitrophic effect at cellular and subcellular level.