Chronic administration of plasma from exercised rats to sedentary rats does not induce redox and metabolic adaptations.

The present study aimed to investigate whether endurance exercise-induced changes in blood plasma composition may lead to adaptations in erythrocytes, skeletal muscle and liver. Forty sedentary rats were randomly distributed into two groups: a group that was injected with pooled plasma from rats that swam until exhaustion and a group that was injected with the pooled plasma from resting rats (intravenous administration at a dose of 2 mL/kg body weight for 21 days). Total antioxidant capacity, malondialdehyde and protein carbonyls were higher in the plasma collected from the exercised rats compared to the plasma from the resting rats. Νo significant difference was found in blood and tissue redox biomarkers and in tissue metabolic markers between rats that received the "exercised" or the "non-exercised" plasma (P > 0.05). Our results demonstrate that plasma injections from exercised rats to sedentary rats do not induce redox or metabolic adaptations in erythrocytes, skeletal muscle and liver.

Plasma serotonin and markers of bone formation and bone resorption in hemodialysis patients.

INTRODUCTION: Serotonin receptors are present in osteoblasts and osteoclasts, and serotonin affects bone metabolism. The association of plasma serotonin with markers of bone formation and bone resorption in hemodialysis patients was evaluated. MATERIALS AND METHODS: Twenty-four hemodialysis patients (11 diabetics) and 22 healthy volunteers were enrolled into the study. Serotonin was assessed in platelet-free plasma, whereas the markers of osteoblastic activity N-terminal midfragment osteocalcin and total procollagen type-1 aminoterminal propeptide as well as the marker of osteoclastic activity beta-isomerized C-terminal cross-linked peptide of collagen type I were measured in serum. Serum intact parathyroid hormone was also assessed. RESULTS: Serotonin did not significantly differ between hemodialysis patients and healthy volunteers. All evaluated markers of bone metabolism and intact parathyroid hormone were much higher in hemodialysis patients. Serotonin was significantly correlated with all evaluated markers of bone metabolism in hemodialysis patients. Serotonin was reversely related to the patients' age. Serotonin, osteocalcin, procollagen type-1 aminoterminal propeptide, and beta-isomerized C-terminal cross-linked peptide of collagen type I were much lower in diabetic hemodialysis patients. CONCLUSIONS: Serotonin may increase both bone formation and bone resorption in hemodialysis patients. The reverse relation of serotonin to patients' age as well as its lower levels in diabetic hemodialysis patients indicate that low plasma serotonin may contribute to the higher incidence of low-turnover bone disease that characterizes old and diabetic hemodialysis patients.

Perilipin-1 in hemodialyzed patients: association with history of coronary heart disease and lipid profile.

Perilipin-1 surrounds lipid droplets in both adipocytes and in atheroma plaque foam cells and controls access of lipases to the lipid core. In hemodialysis (HD) patients, dyslipidemia, malnutrition, inflammation and atherosclerosis are common. Thirty-six HD patients and 28 healthy volunteers were enrolled into the study. Ten HD patients suffered from coronary heart disease (CHD). Perilipin-1, triglycerides, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL-C), body mass index, albumin, geriatric nutritional risk index, normalized protein catabolic rate, interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) were measured. Perilipin-1 did not differ between HD patients and healthy volunteers. IL-6 and TNF-α were higher in HD patients. The evaluated nutritional markers and the markers of inflammation did not differ between HD patients with high perilipin-1 levels and HD patients with low perilipin-1 levels. Regarding the lipid profile, only HDL-C differed between HD patients with high perilipin-1 levels and HD patients with low perilipin-1 levels, and it was higher in the first subgroup. Perilipin-1 was significantly higher in HD patients without CHD. Perilipin-1 is detectable in the serum of HD patients and it is associated with increased HDL-C and decreased incidence of CHD.