[Circadian rhythm of prolactin in patients with chronic renal failure]

This study was aimed to answer the following questions: 1. Is there the circadian rhythm in serum concentration of prolactin preserved in male patients with chronic renal failure. 2. Does hemodialysis, used in treatment of uremia, influence PRL circadian variations. 3. Is there statistically significant difference between hormonal circadian rhythm determined on the day of hemodialysis and on the interdialytic day. For this purpose circadian patterns of PRL and their characteristics were studied in 32 uremic men and 16 healthy men. 16 uremic males were nondialyzed and 16 were hemodialyzed. In all investigated cases the basal serum concentration of PRL were determined 8-times a day at 3-hour intervals. In hemodialyzed patients the measurements of hormone were conducted on the day of dialysis session and on the following day. PRL serum concentration were determined using an immunoradiometric assay. To estimate the circadian rhythms COSINOR computer analysis was employed. Existence of abnormal circadian rhythm of PRL was noted in both hemodialyzed and non-dialyzed patients, significantly shifted toward earlier hours in comparison with healthy subjects. In uremic men PRL circadian rhythm is not significantly influenced by single hemodialysis session. Long-term hemodialysotherapy significantly influences circadian rhythm of PRL in uremic men. This influence is expressed by partial normalization of PRL acrophase and normalization of amplitude.