Sodium bicarbonate treatment prevents gastric emptying delay caused by acute exercise in awake rats.

Physical exercise, mainly after vigorous activity, may induce gastrointestinal dysmotility whose mechanisms are still unknown. We hypothesized that physical exercise and ensuing lactate-related acidemia alter gastrointestinal motor behavior. In the present study, we evaluated the effects of short-term exercise on gastric emptying rate in awake rats subjected to 15-min swimming sessions against a load equivalent to 5% of their body weight. After 0, 10, or 20 min of exercise testing, the rats were gavage fed with 1.5 ml of a liquid test meal (0.5 mg/ml of phenol red in 5% glucose solution) and euthanized 10 min postprandially to measure fractional gastric dye recovery. In addition to inducing acidemia and increasing blood lactate levels, acute exercise increased (P < 0.05) gastric retention. Such a phenomenon presented a positive correlation (P < 0.001) between blood lactate levels and fractional gastric dye recovery. Gastric retention and other acidbase-related changes were all prevented by NaHCO3 pretreatment. Additionally, exercise enhanced (P < 0.05) the marker's progression through the small intestine. In anesthetized rats, exercise increased (P < 0.05) gastric volume, measured by a balloon catheter in a barostat system. Compared with sedentary control rats, acute exercise also inhibited (P < 0.05) the contractility of gastric fundus strips in vitro. In conclusion, acute exercise delayed the gastric emptying of a liquid test meal by interfering with the acid-base balance.

Effects of Bixa orellana L. seeds on hyperlipidemia.

Bixa orellana L., urucum, or urucu, a native tropical tree of Central and South American rain forests is used to treat various diseases in popular medicine. In Ceará, Northeast of Brazil, the seeds of urucum have been used for the treatment of high lipid blood levels. The present study investigated the effects of the aqueous extract from Bixa orellana seeds (AEBO) in mice with hyperlipidemia induced by tyloxapol, fructose and ethanol. In hyperlipidemia induced by Triton WR1339, 400 and 800 mg/kg AEBO reduced triglycerides (TG) serum levels at 24 h and 48 h. In the study of hypertriglyceridemia induced by fructose, AEBO in doses of 400 mg/kg and 800 mg/kg reduced TG levels by 48.2% and 48.7%, respectively. Finally, the ethanol experimental model with 400 mg/kg AEBO promoted a reduction of 33.6% of TG levels, while the 800 mg/kg concentration reduced hypertriglyceridemia in 62.2%. In conclusion, the aqueous extract of the seeds of Bixa orellana was capable of reversing the hypertriglyceridemia induced by Triton, fructose and ethanol, demonstrating a hypolipidemic effect. However, further studies are necessary to discover the precise mechanism of action.

Antibacterial and antiparasitic effects of Bothropoides lutzi venom.

The therapeutic potential of toxins has aroused great interest in the scientific community. Microbial resistance is a serious current public health problem, in part because of the wide use of antimicrobial drugs. Furthermore, there are several problems in the treatment of parasitic diseases such as leishmaniosis and Chagas' disease, including the low efficacy in some clinical phases of the diseases and the loss of effectiveness of benzonidazole in the chronic phase of Chagas' disease. In this context, the aim of this work was to study the antimicrobial and antiparasitic effects of Bothropoides lutzi total venom (BltTV). The venom exerted an antibacterial effect on S. aureus, with MIC=MLC=200 microg/mL. The inhibitory effects of BltTV on promastigote forms of Leishmania amazonensis and L. chagasi were assessed by counting of viable cells after incubation with BltTV. IC50 values of 234.6 microg/mL and 61.2 microg/mL, were obtained, respectively. Furthermore, the venom repressed epimastigote forms of Trypanosoma cruzi growth. Finally, BltTV was verified to affect murine peritoneal macrophages, causing a cytotoxic effect at the highest concentrations (100 and 50 microg/mL). In conclusion, Bothropoides lutzi venom demonstrated antibacterial and antiparasite effects, suggesting that the venom contains some substance(s) of therapeutic value.

Inhibitory effects of sertraline in rat isolated perfused kidneys and in isolated ring preparations of rat arteries.

OBJECTIVES: Sertraline is often prescribed to patients suffering with end stage renal disease, but its action on kidney has not been investigated. We aimed to investigate the pharmacological action of sertraline on rat kidney with emphasis on the underlying mechanisms involved in the vascular actions of the drug. METHODS: The effects of sertraline were evaluated in rat isolated perfused kidneys and on ring preparations of mesenteric or segmental rat renal artery. KEY FINDINGS: In kidneys, sertraline prevented the effects of phenylephrine on perfusion pressure, glomerular filtration rate, urinary flow and renal vascular resistance. In mesenteric rings sertraline inhibited phenylephrine-induced contractions with potency 30-times lower than verapamil. Sertraline reversed sustained contractions induced by phenylephrine or 60mm K(+) within a similar concentration range. In segmental isolated rings, sertraline also reversed contractions induced by phenylephrine or 60mm K(+) with the same concentration range, but with higher potency compared with mesenteric preparations. Under Ca(2+) -free conditions, sertraline did not change the intracellularly-mediated phasic contractions induced by phenylephrine or caffeine. Sertraline was ineffective against contractions induced by extracellular Ca(2+) restoration after thapsigargin treatment and Ca(2+) store depletion with phenylephrine. Conversely, sertraline decreased the contractions induced by Ca(2+) addition in tissues under high K(+) solution or phenylephrine plus verapamil. CONCLUSIONS: In rat isolated kidneys and in rat ring preparations of mesenteric or renal vessels, sertraline had antispasmodic effects that appeared to be caused by a direct action on vascular smooth muscle cells. Its actions were ineffective against Ca(2+) -releasing intracellular pathways, but appeared to interfere with sarcolemmal Ca(2+) influx with reduced permeability of both receptor- and voltage-gated Ca(2+) channels.

Betulinic acid, a natural pentacyclic triterpenoid, prevents abdominal fat accumulation in mice fed a high-fat diet.

In the search for potential antiobese agents from natural sources, this study investigated the effects of betulinic acid (BA), a pentacyclic triterpene from Clusia nemorosa L. (Clusiaceae), in mice on a high-fat diet (HFD). Adult male Swiss mice (n = 8) treated or not with BA (50 mg/L, in drinking water) were fed a HFD during 15 weeks. Mice treated with BA and fed a HFD showed significantly (P < 0.05) decreased body weights, abdominal fat accumulation, blood glucose, plasma triglycerides, and total cholesterol relative to their respective controls fed no BA. Additionally, BA treatment, while significantly elevating the plasma hormone levels of insulin and leptin, decreased the level of ghrelin. However, it caused a greater decrease in plasma amylase activity than the lipase. These findings suggest that BA has an antiobese potential through modulation of fat and carbohydrate metabolism, and it may be a suitable lead compound in the treatment of obesity.

Medication noncompliance in chronic kidney disease.

BACKGROUND: Medication noncompliance has a harmful impact on reaching therapeutic goals of delaying the progression of chronic kidney disease (CKD). The aim of the present study is to calculate the prevalence of medication noncompliance and to identify medication noncompliance-associated factors in CKD. METHODS: A cross-sectional study was performed with 130 CKD patients from a university nephrology outpatient clinic, mean age 48.8 +/- 15.8 years, who were continuously self-administering an antihypertensive or immunosuppressive drug, and who were neither on dialysis nor had received a kidney transplant. Noncompliance was measured through self-report (during an interview) and physician assessment. Patients were considered noncompliers if noncompliance had been detected by any of these methods. Sociodemographic, clinical and laboratory and medication characteristics were surveyed, as well as patients' knowledge regarding prescribed medicines and opinions of the quality of the health care service provided. RESULTS: Prevalence of medication noncompliance was 36.9% (95% confidence interval [95% CI], 28.6%-45.8%). Lack of access to medicines was the most commonly reported problem with medication use (62.5%). Multiple logistic regression analysis showed that patients' insufficient knowledge regarding prescribed medicines (p=0.040) and bad opinions of the quality of the provided health care service (p=0.027) were independently associated with noncompliance. CONCLUSIONS: Medication noncompliance prevalence was high among the patients studied. Lack of access to medicines remains an important public health problem. The noncompliance-associated factors identified in CKD were the patients' poor knowledge regarding the pharmacotherapy and dissatisfaction with the health care service provided.