ABSTRACT
Background: Many endogenous peptides play important regulatory roles in angiogenesis by modulating endothelial cell behavior. Adrenomedullin (AdM) is one of such factors. Angiogenesis and vascular endothelial growth factor (VEGF) are indistinguishable. Exposure to cold environment stimulates capillary angiogenesis.Objectives: Examine the effect of the bioactive peptide AdM on VEGF levels in rat liver, lung, brain, and heart tissues after cold stress treatment.Methods: Male wistar rats were divided into four groups as control, AdM treatment, cold stress and AdM+cold stress treated groups. In AdM-treated group, animals received intraperitoneal injection of AdM (2000 ng/kg body weight) once a day during a week. For the cold stress exposure, the rats were kept in separate cages at 10°C for a week.Results: The administration of AdM increased VEGF levels in all tissues in cold exposed rats.Conclusion: AdM may be a major regulatory factor in angiogenesis by modulating VEGF levels that is closely associated with cold exposure-related metabolic stimulation.Keywords: Adrenomedullin, angiogenesis, cold stress, rat, vascular endothelial growth factor (VEGF)
ABSTRACT
To investigate the levels of serum cortisol, dehydroepiandrosterone sulfate [DHEA-S], nitric oxide [NO] and adrenomedullin [AM] in schizophrenic patients. Sixty-six male patients with chronic schizophrenia and 28 normal male subjects participated in this study. The duration of disease was 145 +/- 120 [mean +/- SD] months. Serum levels of cortisol and DHEA-S were measured by electrochemiluminescence; plasma nitrite levels as an index of NO were measured with the Griess reaction, while plasma AM concentration was measured by using high-performance liquid chromatography. Patients [12.48 +/- 3.2 micro g/dl], as compared to controls [10.31 +/- 3.1 micro g/dl], had higher levels of baseline cortisol [p < 0.05]. DHEA-S levels were lower in patients though this did not reach statistical significance [302 +/- 156 micro g/dl compared to control, 322 +/- 96 micro g/dl, p > 0.05]. The mean levels of plasma AM and NO in the schizophrenic group [44.33 +/- 5.07 pmol/l and 36.27 +/- 17.6 micro mol/l] were significantly higher than the levels in the control group [14.56 +/- 4.03 pmol/l and 32.54 +/- 7.14 micro mol/l; p < 0.001, p < 0.03, respectively]. There was a positive association between duration of disease and cortisol/DHEA-S ratio and cortisol level. The data show that schizophrenia is associated with abnormal levels of cortisol, DHEA-S, NO and AM