Effects of coconut oil long-term supplementation in Wistar rats during metabolic syndrome - regulation of metabolic conditions involving glucose homeostasis, inflammatory signals, and oxidative stress.

This study was designed to evaluate the long-term effects of Fructose (20%) feeding in rats, simulating metabolic syndrome (MetS), and the effects of coconut oil (C.O.) supplementation when administered in a MetS context. MetS is a cluster of systemic conditions that represent an increased chance of developing cardiovascular diseases and type 2 diabetes in the future. C.O. has been the target of media speculation, and recent studies report inconsistent results. C.O. improved glucose homeostasis and reduced fat accumulation in Fructose-fed rats while decreasing the levels of triglycerides (TGs) in the liver. C.O. supplementation also increased TGs levels and fructosamine in serum during MetS, possibly due to white adipose tissue breakdown and high fructose feeding. Pro-inflammatory cytokines IL-1ß and TNF-α were also increased in rats treated with Fructose and C.O. Oxidative stress marker nitrotyrosine is increased in fructose-fed animals, and C.O. treatment did not prevent this damage. No significant changes were observed in lipoperoxidation marker 4-Hydroxynonenal; however, fructose feeding increased total conjugated dienes and caused conjugated dienes to switch their conformation from cis-trans to trans-trans, which was not prevented by C.O. treatment. Potential benefits of C.O. have been reported with inconsistent results, and indeed we observed some benefits of C.O. supplementation in aiding weight loss, fat accumulation, and improving glucose homeostasis. Nonetheless, we also demonstrated that long-term C.O. supplementation could present some problematic effects with higher risk for individuals suffering MetS, including increased TGs and fructosamine levels and conformational changes in dienes.

STC1 interference on calcitonin family of receptors signaling during osteoblastogenesis via adenylate cyclase inhibition.

Stanniocalcin 1 (STC1) and calcitonin gene-related peptide (CGRP) are involved in bone formation/remodeling. Here we investigate the effects of STC1 on functional heterodimer complex CALCRL/RAMP1, expression and activity during osteoblastogenesis. STC1 did not modify CALCRL and ramp1 gene expression during osteoblastogenesis when compared to controls. However, plasma membrane spatial distribution of CALCRL/RAMP1 was modified in 7-day pre-osteoblasts exposed to either CGRP or STC1, and both peptides induced CALCRL and RAMP1 assembly. CGRP, but not STC1 stimulated cAMP accumulation in 7-day osteoblasts and in CALCRL/RAMP1 transfected HEK293 cells. Furthermore, STC1 inhibited forskolin stimulated cAMP accumulation of HEK293 cells, but not in CALCRL/RAMP1 transfected HEK293 cells. However, STC1 inhibited cAMP accumulation in calcitonin receptor (CTR) HEK293 transfected cells stimulated by calcitonin. In conclusion, STC1 signals through inhibitory G-protein modulates CGRP receptor spatial localization during osteoblastogenesis and may function as a regulatory factor interacting with calcitonin peptide members during bone formation.

Effects of four additive solutions on canine leukoreduced red cell concentrate quality during storage.

BACKGROUND: Additive solutions (AS) and prestorage leukoreduction (LR) are important tools used to maintain erythrocyte viability during storage and avoid transfusion reactions in recipients, respectively. OBJECTIVES: The purpose of the study was to determine the efficacy of a WBC filter (Immugard IIIRC) and compare the effect of 4 AS (phosphate-adenine-glucose-guanosine-gluconate-mannitol [PAGGGM], saline-adenine-glucose-mannitol [SAGM], Adsol, Optisol) on the in vitro quality of canine leukoreduced packed RBC units (pRBC) stored for 41 days. METHODS: Five hundred milliliters of blood were collected from 8 healthy dogs each into 70 mL of citrate-phosphate-dextrose (CPD) solution, and were leukoreduced by a polyurethane filter. pRBC of each dog were divided equally into 4 bags containing a different AS. Bags were stored for 41 days at 4°C and evaluated every 10 days. Variables analyzed included pH, PCV, and% hemolysis, and lactate, glucose, potassium, sodium, ATP, and 2,3-diphosphoglycerate (2,3-DPG) concentrations. RESULTS: The LR resulted in residual WBC counts comparable to human standards. During storage, pH, and glucose, 2,3-DPG, and ATP concentrations decreased, and hemolysis, and lactate, sodium, and potassium concentrations increased (P < .05). Significant differences between AS were seen in the glucose and sodium concentrations, due to the composition of AS. Also, the pH maintained by PAGGGM at day 21 was significantly higher than that seen with SAGM or Adsol. CONCLUSIONS: All AS used gave satisfactory results during the first 21 days of storage based on the degree of hemolysis, and on ATP and 2,3-DPG concentrations. When compared with day 1 values, significant changes were seen in these variables by day 31 with all AS.