The effect of LHRH antagonist cetrorelix in crossover conditioned media from epithelial (BPH-1) and stromal (WPMY-1) prostate cells.

Stromal cells strictly modulate the differentiation of the normal prostate epithelium. In benign prostatic hyperplasia (BPH) tissue, the ratio of stromal to epithelial cells reaches a 5:1 ratio. In this study, we evaluated the effects of crossover conditioned media (CM) of stromal and epithelial prostate cells before and after treatment with LHRH antagonist Cetrorelix. WPMY-1 human prostate stromal cells and BPH-1 human benign prostatic hyperplasia cells were cultured in vitro and the effects of crossover conditioned media (CM) from those cells were studied. We evaluated the effect of Cetrorelix on the expression of PCNA and p53 in those cells. We then studied the effect of Cetrorelix on BPH-1 cells cultured with the CM from WPMY-1 cells, as well as the mechanisms which govern these interactions. CM from WPMY-1 cells strongly stimulated the proliferation of BPH-1 cells in a dose dependent manner, while CM from BPH-1 cells only slightly increased the proliferation of WPMY-1 cells. Cetrorelix inhibited the proliferation of both cell lines and the expression of PCNA, while the expression of p53 was increased. Cetrorelix also inhibited the proliferation of BPH-1 cells stimulated with the CM from WPMY-1 cells. In the crossover experiment, conditioned media from WPMY-1 and BPH-1 cells increased the expression of phosphorylated ERK1/2 and STAT3. Our results support previous observations on the bidirectional stromal-epithelial interactions in prostate gland and shed more light on the mechanistic action of those effects. Our study strongly supports the hypothesis that LHRH antagonists may be beneficial for BPH prevention and treatment.

Angiotensins II and IV modulate adrenocortical cell proliferation in ovariectomized rats.

Effects of angiotensins II (AngII), angiotensin IV (AngIV, 3-8 fragment of angiotensin II) and losartan (an antagonist of angiotensin receptor type 1) on the proliferation of adrenocortical cells in ovariectomized rats have been studied. The incorporation of bromodeoxyuridine (BrdU) into cell nuclei was used as an index of cell proliferation. AngIV decreased BrdU labeling index mainly in the reticularis zone and losartan (Los) was able to partially reverse this inhibitory effect of AngIV. AngII had no effect on the adrenocortical cell proliferation when given alone, however Los given simultaneously diminished BrdU incorporation into nuclei of glomerulosa and reticularis zones as compared with AngII. These findings suggest that AngII and AngIV modulate adrenocortical cell proliferation in ovariectomized rats.

Safety of various methods of intensive insulin therapy in hospital condition assessed by hypoglycaemic episodes detected with the use of continuous glucose monitoring system.

PURPOSE: The aim of the study was to determine the safety of three intensive insulin therapy methods: multiple daily insulin injections (MDI), continuous subcutaneous insulin infusion (CSII) and continuous intravenous insulin infusion (IVII) used in poorly controlled type 2 diabetic patients in hospital condition. The safety of these intensive insulin therapy methods was measured by the assessment of number and duration of symptomatic and symptomfree hypoglycaemic events with use of Continuous Glucose Monitoring System (CGMS, Medtronic MiniMed). MATERIAL AND METHODS: The study comprised 90 type 2 diabetic patients treated with conventional insulin therapy based on a twice daily injections with mean glucose profile values > 14 mmol/l. The patients were randomized into three groups according to the method of insulin treatment. The first group was treated with MDI, the second group with CSII and the third with IVII. The glucose monitoring with the use of CGMS lasted 48 hours and was conducted on the second and on the third day of intensive insulin therapy. Glucose level below 3.5 mmol/l were recognized as hypoglycaemic episode. Intensive insulin treatment was continued until "near normoglycaemia" (glucose levels 4.5-10.0 mmol/l) was achieved and then conventional insulin therapy was readministrated. RESULTS: Mean number of symptomatic hypoglycaemic events detected with CGMS was two times higher for MDI than for IVII (p = 0.04) and for CSII (p = 0.04). Number of symptomfree hypoglycaemic events detected with CGMS was higher for MDI than for IVII and CSII, but the differences were insignificant (NS). Mean duration of one symptomfree hypoglycaemic event detected with CGMS was longer in MDI than in CSII (p = 0.02) and IVII (p = 0.03). It was not observed significant differences in mean duration of one symptomatic hypoglycaemic episode between studied groups (NS). CONCLUSIONS: The results of study suggest that CSII and IVII treatment is associated with essentially lower number of symptomatic hypoglycaemic events and shorter mean duration of one symptomfree hypoglycaemic event than MDI.

Effect of the growth hormone-releasing hormone [GHRH(1-44)NH2] on IL-6 and IL-8 secretion from human peripheral blood mononuclear cells in vitro.

OBJECTIVE: Bidirectional communication between the neuroendocrine and immune systems is now a subject of an intensive investigation. Growth hormone-releasing hormone (GHRH) is synthesized by the hypothalamus, but is present also in the immune cells. Some recent data indicate also an immunomodulatory role of the neuropeptide. The aim of the study was to examine the influence of GHRH(1-44)NH2 on interleukin-6 and interleukin-8 secretion from human peripheral blood mononuclear cells cultured in vitro. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated by centrifugation using Böyum technique and cultured in a humidified atmosphere of 5 % CO2 and 95 % O2 at 37 degrees C for 24 hours in the presence of lipopolysaccharide (LPS) at the concentration of 2 microg/ml and GHRH(1-44)NH2 (the final neuropeptide concentrations to be tested were 10(-12) to 10(-6) M). ELISA methods were used to measure IL-6 and IL-8 concentrations in the supernatants of cultured cells RESULTS: GHRH(1-44)NH2 influenced IL-6 secretion from cultured cells, but significant inhibition of IL-6 release was observed at 10-6 M (p < 0.001). The negative correlation between the GHRH concentration studied and the IL-6 level in the supernatants was found (r = -0.759; p < 0.001). GHRH had no influence on the secretion of IL-8 from activated PBMC. CONCLUSIONS: Our results demonstrate that GHRH in vitro modulates IL-6 secretion from the human peripheral blood mononuclear cells, without any significant effect on IL-8 secretion.

Effect of growth hormone-releasing hormone (GHRH) and GHRH antagonist (MZ-4-71) on interferon-gamma secretion from human peripheral blood mononuclear cells in vitro.

Numerous reports indicate close interactions between the neuroendocrine and the immune systems. Hypothalamic neuropeptide, growth hormone-releasing hormone (GHRH) stimulates growth hormone (GH) secretion from the anterior pituitary gland, but recently some immunomodulatory properties of this peptide have also been demonstrated. In the present studies we evaluated the effect of human synthetic GHRH(1-44)NH(2) and GHRH antagonist (MZ-4-71) on interferon (IFN)-gamma secretion from human peripheral blood mononuclear cells (PBMC). GHRH(1-44)NH(2) at 10(-10), 10(-8) and 10(-6) M concentrations significantly (p < 0.05) increased the IFN-gamma level in supernatants of cultured cells, as compared with the controls. GHRH antagonist (MZ-4-71) at 10(-10), 10(-8) and 10(-6) M concentrations diminished the IFN-gamma level in supernatants in a dose-dependent manner, but statistically significant differences were observed only at 10(-8) M and 10(-6) M (p < 0.05 vs controls). Our results demonstrate that GHRH and GHRH antagonist MZ-4-71 can modulate IFN-gamma secretion in vitro by human peripheral blood mononuclear cells.

GH-RH antagonist (MZ-4-71) inhibits VEGF secretion and proliferation of murine endothelial cells.

Angiogenesis plays a key role in solid tumor formation, invasiveness and metastasis. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen that is necessary in the process of neovascularisation. Antagonists of growth hormone-releasing hormone (GH-RH) have been shown to suppress both in vivo and in vitro growth and metastasis of many human cancer cell lines. The mechanisms that mediate the antitumorigenic actions of these antagonists involve direct and indirect pathways, but are not completely elucidated. We have examined the effect of GH-RH antagonist MZ-4-71 on proliferation activity and VEGF release from cultured murine endothelial cells HECa10 in vitro. MZ-4-71 at 10(-8) to 10(-6) M concentrations inhibited the proliferative activity of cultured cells and suppressed the release of VEGF into supernatants of 72 h endothelial cell cultures. To our knowledge this is the first study reporting antiangiogenic properties of GH-RH antagonists.