losartan-potassium and Hyperprolactinemia

The prolactin (PRL) receptor (R), a member of the cytokine hemopoietin receptor superfamily, has been shown to activate early differentiation steps along the erythroid pathway. In particular PRL, a product of bone marrow stroma, induces functional erythropoietin (EPO)-R on CD34+ hemopoietic progenitors. In this study, expression of EPO-R mRNA and responsiveness to EPO were assessed on enriched hemopoietic progenitor cells (HPC) from seven hyperprolactinemic and three normoprolactinemic patients and two normal subjects. Expression of EPO-R mRNA by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was found in HPC of four out of seven hyperprolactinemic patients but not in normoprolactinemic patients or normal donors. Development of EPO-dependent Colony Forming Unit-Erythroid (CFU-E) colonies in semi-solid medium was observed only in hyperprolactinemic patients (six out of seven). A much higher number of CFU-E colonies was observed in the four patients with a positive EPO-R message. We conclude from these data that abnormally high levels of PRL may increase the number of EPO-responsive hemopoietic precursors in vivo as they do in vitro. Since hyperprolactinemia associates in these patients with depressed EPO production, it may be regarded as a compensatory mechanism for the reduced availability of the hemopoietic factor.

Topics: Colony-Forming Units Assay; Erythroid Precursor Cells; Erythropoietin; Female; Humans; Hyperprolactinemia; Male; Prolactin; Receptors, Erythropoietin; Renal Dialysis; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

Correction of anemia in long-term hemodialysis patients by recombinant human erythropoietin (r-HuEPO) has been reported to improve sexual function. As elevated serum prolactin levels are believed to contribute to altered sexual function in uremia, we followed serum prolactin and testosterone levels during four months of r-HuEPO therapy. Within these four months, hematocrit values rose from 23.7 +/- 1.2 to 35.7 +/- 0.2% and hemoglobin from 7.3 +/- 0.3 to 11.3 +/- 0.4 g/100 ml. In parallel, serum prolactin values decreased significantly, from 66.9 +/- 9.3 to 9.6 +/- 2.6 ng/ml in females and from 39.5 +/- 10.5 to 10.3 +/- 1.0 ng/ml in male dialysis patients. Testosterone concentrations were in the lower normal range in male patients and remained unchanged during r-HuEPO therapy. Sexual function improved in four out of seven males, and five out of nine female patients started to have regular menstruations again. It appears that treatment of anemia in end-stage renal disease by r-HuEPO may improve sexual function by lowering elevated serum prolactin concentrations.

Topics: Adult; Anemia; Erectile Dysfunction; Erythropoietin; Female; Humans; Hyperprolactinemia; Kidney Failure, Chronic; Libido; Male; Menstruation; Prolactin; Recombinant Proteins; Renal Dialysis; Testosterone