Effects of hypoxia on the distribution of calcium in arterial smooth muscle cells of rats and swine

Exposure to hypoxia caused an increase in the hematocrit and right heart weight of experimental rats, but did not affect calcium-45 uptake by pulmonary arterial smooth muscle cells. However, autoradiographic studies showed that hypoxia apparently caused a shift of 45-Ca from primarily extracellular sites in arteries of control rats to intracellular sites in tissues of hypertensive rats. Cytochemical studies of calcium distributions in pulmonary arterial smooth muscle cells support the autoradiographic data and show that in both rats and swine the majority of pyroantimonate granules occur extracellularly in control tissues. In contrast, hypoxic tissues displayed a greatly reduced number of granules in extracellular sites and an increase in the amount of precipitate in intracellular sites. In pulmonary arterial smooth muscle cells from hypoxic rats most of the precipitate was associated with the caveolae intracellulares, while in corresponding cells from hypoxic swine the majority of the pyroantimonate granules were localized to the sarcoplasmic reticulum. Hypoxia may produce pulmonary hypertension by interfering with the ability of the arterial smooth muscle cells to maintain transmembrane ionic gradients, thus producing an effective increase in cytoplasmic calcium levels. The increased calcium may then activate the contractile apparatus to produce a sustained vasoconstriction.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47664/1/441_2004_Article_BF00223235.pd

Metabolic and nutritional profile of obese adolescents with nonalcoholic fatty liver disease

Background: the incidence of nonalcoholic fatty liver disease (NAFLD) is increasing due to its prevalence in obesity, diabetes, and insulin-resistance syndrome. the best treatment protocol for NAFLD has not been determined. However, there is evidence that exercise and nutritional intervention can improve and prevent it. the aim of the present study was to evaluate the dietary and metabolic profiles of obese adolescents with NAFLD who participated in a multidisciplinary program.Patients and Methods: We studied 43 adolescents ages 15 to 19 years (17.18 +/- 1.66 years) with a body mass index (BMI) >= 30, consisting of 30 patients without NAFLD (BMI = 35.80 +/- 3.44 kg/m(2)) and 13 with NAFLD (BMI=33.4 +/- 2.34kg/m(2)). the NAFLD diagnosis was determined by ultrasonography. Blood samples were collected to analyze glycemia, hepatic aminotransferase levels, and lipid profiles. Insulin resistance was measured by homeostasis model assessment insulin-resistance index (HOMA-IR). the analyses of baseline and postintervention food intake were made by a 3-day inquiry.Results: At baseline conditions, the patients with NAFLD showed significant differences in body mass, BMI, and visceral and subcutaneous fat. Glucose and visceral and subcutaneous fat presented a significant reduction after treatment in patients with NAFLD. Analyzing the food intake, at baseline we observed a positive correlation between the visceral obesity and lipid consumption only in patients with NAFLD. We also observed significant decrease in energy and cholesterol consumption in patients with NAFLD after the multidisciplinary therapy.Conclusions: the intervention promoted a decrease in the prevalence of NAFLD, a significant decrease in visceral obesity, and improved HOMA-IR, glycemia, and serum lipid levels that are risk factors for NAFLD. in summary, the multidisciplinary program is essential in the treatment and prevention of NAFLD.Universidade Federal de São Paulo, EPM, São Paulo, BrazilUniversidade Federal de São Paulo, EPM, São Paulo, BrazilWeb of Scienc