Reactivity of mesenteric and aortic rings from trained rats fed with high caloric diet

A strong association between the benefits of physical exercise on the cardiovascular disease with an improvement of the endothelium-derived relaxing factor production has been consistently shown. The purpose of this study was to evaluate the effect of exercise training associated with high caloric diet in the reactivity of rat mesenteric and aortic rings. Experimental protocol consisted of 4 weeks of high caloric diet consumption previous to 4 weeks of run training (1.2 km/h, 0% grade, in sessions of 60 min, 5 days/week). Concentrations of triglycerides, glucose, insulin and nitrite/nitrate levels were measured and atherogenic index was calculated. Concentration-response curves to acetylcholine (10 nM-100 mu M), sodium nitroprusside (100 pM-100 nM) and phenylephrine (1 nM-3 mu M) were obtained. Exercise training reduced body mass (6%) and triglyceride levels (about 54%), without changes in glucose and insulin concentrations. An improvement of endothelium-dependent relaxation responses to acetylcholine in mesenteric and aortic rings was observed in trained group. No changes were seen for sodium nitroprusside and phenylephrine. In conclusion, our study is the first to show clearly that run training promotes an improvement of the endothelium-dependent relaxing response in aorta and mesenteric rings from rats fed with high caloric diet and that is associated with increase of NO production. (c) 2006 Elsevier B.V. All rights reserved.

Feed restriction and a diet's caloric value: The influence on the aerobic and anaerobic capacity of rats

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Aerobic capacity of rats recovered from fetal malnutrition with a fructose-rich diet

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Recovery of rat growth and lipid profiles in adult rats subjected to fetal protein malnutrition with a fructose-rich diet

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Exercise test and glucose homeostasis in rats treated with alloxan during the neonatal period or fed a high calorie diet

Background: Animal models appear well-suited for studies into the role of exercise in the prevention of non-insulin-dependent diabetes mellitus (NIDDM). The aim of the present study was to analyze glucose homeostasis and blood lactate during an exercise swimming test in rats treated with alloxan during the neonatal period and/or fed a high calorie diet from weaning onwards.Methods: Rats were injected with alloxan (200 mg/kg, i.p.) or vehicle (citrate buffer) at 6 days of age. After weaning, rats were divided into four groups and fed either a balanced diet or a high-caloric diet as follows: C, control group (vehicle + normal diet); A, alloxan-treated rats fed the normal diet; H, vehicle-treated rats fed the high-caloric diet; and HA, alloxan-treated rats fed the high-caloric diet.Results: Fasting serum glucose levels were higher in groups A and AH compared with the control group. The Homeostatic Model Assessment index varied in the groups as follows: H > A > HA = C. There were no differences in free fatty acids or blood lactate concentrations during the swim test.Conclusions: Alloxan-treated rats fed a normal or high-caloric diet have the potential to be used in studies analyzing the role physical exercise plays in the prevention of NIDDM.

High-fat diet associated with obesity induces impairment of mouse corpus cavernosum responses

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Exercise counteracts fatty liver disease in rats fed on fructose-rich diet

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Metabolic responses to acute physical exercise in young rats recovered from fetal protein malnutrition with a fructose-rich diet

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Fructose-rich diet leads to reduced aerobic capacity and to liver injury in rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ontogenetic diet shifts of a Neotropical catfish, Pimelodus maculatus (Siluriformes, Pimelodidae): An ecomorphological approach

This study analyses the ontogenetic diet shifts of a Neotropical catfish, Pimelodus maculatus ( Siluriformes, Pimelodidae), from an ecomorphological standpoint. We collected 241 individuals in the Piracicaba River ( Brazil) and, in the laboratory, seven morphometric variables were recorded from each specimen: standard length (SL), body depth, head length, snout length, eye diameter, mouth height and mouth width. After standardizing these measurements ( as a proportion of SL), linear regressions were run to determine whether their growth was isometric or allometric in relation to SL. The diet analysis shows that the main food item for fish in the smaller size classes is aquatic insects, while the largest individuals feed mainly on other fish. As the great majority of the morphometric variables analyzed showed isometric growth as a function of SL - which means that these fish do not change their shape significantly during their lives - the ontogenetic diet shifts may be seen as a consequence of the absolute size increment of their mouth gape, which allows individuals to maximize their energetic gain by ingesting larger prey with a higher caloric content.

Diet of buffy tufted-eared marmosets (Callithrix aurita) in a forest fragment in southeastern Brazil

The feeding ecology of the Atlantic forest marmosets (Callithrix spp.) in southeastern Brazil is poorly known, and few studies have focused on buffy tufted-eared marmosets, Callithrix aurita. We determined the food items and investigated the seasonal variation in the diet of a group of four Callithrix aurita in a 17-ha semideciduous forest fragment in southern Minas Gerais State, Brazil. We recorded daily feeding activities between October 1994 and September 1995 using scan sampling at 5-min intervals. The marmosets devoted feeding rime to gums (50.5%), fruits (11%), and animal prey (38.5%) in a fetal of 499 records. Plant resources comprised 27 species from 16 families. They used Acacia paniculata (Mimosoideae, Leguminosae), the main gum source (82%), year-round Maclura tinctoria (Moraceae) was the fruit species that they consumed most (22%). The marmosets preyed on caterpillars (33%), katydids (5%), and homopterans (4%). Feeding on fruits varied seasonally and was inversely related to gum feeding. Consumption of animal prey remained constant over the year. The wide and year-round dependence on gum suggests that Acacia may play a critical role in marmoset persistence in forest fragments.

Diet and habitat use of two sympatric species of Philodryas (Colubridae), in south Brazil

Feeding habits and habitat use of the colubrid snakes Philodryas olfersii and P patagoniensis in southern Brazil are presented here. Philodryas olfersii and P patagoniensis are sympatric in the study area and both dwell in open and forested areas. Specimens preserved in collections and observations of snakes in the field yielded the data. Both species are diet generalists, feeding on small vertebrates, mainly frogs. Philodryas patagoniensis has a broader diet, a less variable frequency of food items, and fed on heavier prey than R olfersii. Seasonal variation in diet occurs in both species. The semi-arboreal Philodryas olfersii is more slender and has a longer tail than the terrestrial R patagoniensis, characters that may reflect differences in microhabitat use. There are a strong relationship between habitat use and frequency of a given food type. Differences in the use of food resources between P. olfersii and P patagoniensis seem to reflect differences in foraging microhabitats used by each species.

Diet of the rattlesnake Crotalus durissus in southeastern Brazil (Serpentes, Viperidae)

Gut contents of 633 live rattlesnakes from southeastern Brazil received at the Instituto Butantanitute, SP, Brazil between 1993 and 1995 were studied. The snakes were weighed, measured and sexed. Two hundred and fifty-nine rattlesnakes had stomach and/or intestinal contents. Prey size was estimated by comparison of prey items with specimens from museum collections. Rodents and small marsupials were the main prey eaten by the rattlesnakes, and only 1% of the items were found in the stomach, whereas 41% of the individuals in the sample had feces in the intestine. There was low correlation between size of snake and prey size. No seasonal difference in frequency was found between fed and not fed males, but the occurrence of fed females was significantly lower during summer than winter months (28.9% and 51.8%, respectively). Fed newborn rattlesnakes had the lowest frequency, and also fed on rodents.

Diet of fishes in Passa Cinco stream, Corumbataí River sub-basin, São Paulo state, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)