Laura Beatriz Mesiano Maifrino

Age related changes of the collagen network of the human heart.

The objective of this work was to study the collagen tissue of the human heart muscle as a function of age. The types of collagen, their disposition, as well as the density of collagen tissue and diameter of collagen fibrils were examined. Pieces of the ventricular wall from 12 human hearts, six from young individuals and six from aged individuals were studied by the Picrosirius-polarization method and by transmission electron microscopy (TEM). The results obtained showed the presence of two types of collagen fibers in the ventricular walls - thin, weakly birefringent, greenish fibers (collagen type III) and thick, yellow or red, strongly, birefringent fibers (collagen type I), both in the endomysium and perimysium. In the hearts obtained from old subjects, there were no significant differences in the arrangement of the collagen fibers in relation to the hearts obtained from young subjects. Measurements of collagen content in myocardial tissue suggest that both perimysial and endomysial collagen type I fibers increase in number and thickness in the old. These histochemical results obtained coincided with the electron microscopic observations in showing increase in the number of collagen fibrils with large diameter in the old hearts. These ultrastructural and histochemical characteristics of collagen may provide insights important to assessing the pathogenesis of the cardiac lesions of several cardiopathies in the aged heart.

Physical activity on endothelial and erectile dysfunction: a literature review

Abstract Physical inactivity, diabetes, hypertension, dyslipidemia, smoking and obesity were associated with imbalance in oxidative stress, leading to endothelial dysfunction. Such dysfunction is present in both cardiovascular disease (CVD) and erectile dysfunction (ED). ED is the persistent inability to achieve or sustain an erection sufficient for satisfactory sexual performance and is one of the first manifestations of endothelial damage in men with CVD risk factors. The purpose of this article is to review the results of studies involving physical activity, CVD, endothelial dysfunction and ED in order to verify its applicability for improving the health and quality of life of men with such disorders. There is consistent evidence that endothelial damage is intimately linked to ED, and this manifestation seems to be associated with the appearance CVDs. On the other hand, physical activity has been pointed out as an important clinical strategy in the prevention and treatment of CVDs and ED mainly associated with improvement of endothelial function. However, further experimental and clinical prospective investigations are needed to test the role of physical exercises in the modulation of endothelial function and their implications on erectile function and the appearance of CVDs.

Effects of Moderate Exercise on the Biochemical, Physiological, Morphological and Functional Parameters of the Aorta in the Presence of Estrogen Deprivation and Dyslipidemia: an Experimental Model

Background: The estrogen deficiency, abnormal lipid profile, weight gain and a sedentary lifestyle are factors associated with the increased prevalence of cardiovascular disease in menopausal women. However, physical exercise practice reduces some of these risk factors. Moreover, it has been shown that exercise has an impact on inflammation, in sympathetic activity and improves endothelial function. Aims: The present study aims to evaluate the effects of moderate aerobic training on biochemical, morphological and physiological parameters in LDL Knockout mice with estrogen deprivation, evaluating the components of the ascending aortic wall. Methods: The animals were randomly divided into six groups (n=5): sedentary control (SC), sedentary control ovariectomized (SCO), trained control ovariectomized (TCO), LDL-Knockout sedentary (KS), LDL-Knockout sedentary ovariectomized (KOS) and LDL-Knockout trained ovariectomized (KOT). The trained groups underwent a protocol of moderate training for 4 weeks on a treadmill with speed and progressive load. After training, blood samples were collected for biochemical assessments and the aorta was removed for dissection and histological morphometry study. In addition, the expression of angiotensin-converting enzyme (ACE) and angiotensin II proteins were examined by immunohistochemistry in all groups of animals. Results: Changes of expressions of ACE and angiotensin II were found when the group was subjected to exercise. The concentrations of cholesterol and triglycerides were lower in the groups of animals with estrogen deprivation and dyslipidemia. In animals that performed exercises we found significant increase (p<0.05) in Vv[lam]; decrease in Vv[col] and CWT, and a tendency for decrease both in TS and IMT when compared to the SC groups. The histological morphometry findings showed consistency in the results of the aorta study when the ovariectomized group underwent the exercise protocol. Conclusion: We conclude that physical training contributed to reducing vessel rigidity and to improvements in vascular compliance, with the increase in volume density of elastic lamellae in the estrogen-deprived groups who had normal cholesterol levels.

Rhythmic stabilization versus conventional passive stretching to prevent injuries in indoor soccer athletes: A controlled clinical trial

OBJECTIVE Indoor soccer is a sport that exposes the athletes to muscle and joint lesions. The effect of rhythmic stabilization (RS) technique to prevent these kinds of lesions in indoor soccer athletes is largely unknown and its use in athletes is controversial. Nevertheless, empiric evidence suggests that RS might be effective to prevent lesions in indoor soccer athletes. A controlled clinical trial of efficacy was performed to test this hypothesis. METHODS Athletes were randomly divided into two groups: a RS group (7 athletes) and passive stretching (PS) group (7 athletes). At the beginning and at the end of the experiment (after four months) all athletes were subjected to clinical evaluation. Assessments were performed by subjective pain intensity, clinical evaluation and measurements of the range of maximal lower limb flexion movement. RESULTS Athletes of both groups had lower limb injuries during the four months. The athletes submitted to RS technique had fewer injuries than those subjected to the PS technique although the difference was not significant. CONCLUSIONS Although no significant difference was found between RS and PS, a trend suggests RS may be more effective than PS to prevent muscular and ankle joint lesions in indoor soccer athletes, but more research is needed.

Morphological and Biochemical Effects on the Skeletal Muscle of Ovariectomized Old Female Rats Submitted to the Intake of Diets with Vegetable or Animal Protein and Resistance Training

Introduction. Sarcopenia is a process characterized by reduction in protein mass and muscle strength with increasing age, especially in the postmenopausal period, resulting in functional limitations and with great impact on the physical autonomy of the elderly. Objective. To evaluate the effects of diets with vegetable proteins (VP) or animal proteins (AP) associated with resistance training (RT) on the structural and biochemical parameters of the medial gastrocnemius muscle in Wistar rats with sarcopenia. Methods. An experimental model with ovariectomized rats was used to induce sarcopenia and resistance training. The histochemical technique was used for the typing of muscle fibers, the cross-sectional area of myocytes, and volume densities of myocytes and interstitium; the technique of Picrosirius stain was used to highlight the collagen fibers. Results. The VP diet was not able to minimize the effects of sarcopenia in the medial gastrocnemius of sedentary animals and when associated with RT, it promoted maintenance of the CSA, attenuating the atrophy of type IIB fibers in the medial gastrocnemius. The AP diet in sedentary animals protected the type I fibers. When combined with RT, the AP promoted muscle remodeling, with reduction in volume density of type I and IIA fibers, and increase of IIB fibers, together with an increase in collagen volume density. Conclusion. The data suggest a tendency to better results of hypertrophy in animal groups that consumed the AP diet, even the sedentary animals, although more evident in those trained.

Use of Anabolic Steroid Altered the Liver Morphology of Rats

El objetivo fue investigar el efecto de la administracion de propionato de testosterona en el higado de ratas. Las ratas se dividieron en los siguientes grupos: control inicial (CI), control de Edad (CE) y grupo anabolico (GA). El propionato de testosterona se administro tres veces por semana durante 16 semanas. Utilizando tecnicas morfocuantitativas, determinamos las densidades de volumen del parenquima lobular y no lobular, area y numero de nucleos de los hepatocitos. Los datos fueron analizados estadisticamente con la media y desviacion estandar, la prueba de ANOVA de una via y un nivel de significacion p0,05. Nuestros resultados mostraron un aumento en los capilares, espacios perisinusoidales y conductos biliares en el grupo CE en comparacion con CI. El GA mostro una disminucion en las celulas hepaticas, la densidad de volumen no lobular y el area de los nucleos de hepatocitos, como tambien un aumento en los capilares, espacios perisinusoidales, conductos biliares, numero de hepatocitos y nucleos no hepatociticos en comparacion AL CI. Concluimos que una toxicidad directa puede haber ocurrido, con la consiguiente perdida de las celulas.

The role of cyclooxygenase-2 on endurance exercise training in female LDL-receptor knockout ovariectomized mice

Estrogen deprivation in postmenopausal women increases cardiovascular risk. Cardiovascular risk as a result of atherosclerosis is able to induce an inflammatory disease as far as cyclooxygenase-2 ( COX-2) expression. The purpose of the study was to investigate the role of COX-2 on exercise training in female mice low-density lipoprotein receptor knockout ( LDL-KO) with or without ovariectomy. A total of 15 female C57BL/6 mice and 15 female LDL-KO mice were distributed into 6 groups: sedentary control, sedentary control ovariectomized, trained control ovariectomized, LDL-KO sedentary, LDL-KO sedentary ovariectomized and LDL-KO trained ovariectomized. The ascending part of the aorta was stained with H&E and COX-2 expression was assessed by immunohistochemistry. Results revealed that ovariectomy as well as exercise training were not able to induce histopathological changes in mouse aorta for all groups investigated. LDL-KO mice demonstrated plaque containing cholesterol clefts, foamy histiocytes and mild inflammatory process for all groups indistinctly. Ovariectomy induced a strong immunoexpression in atherosclerosis lesion of LDL-KO mice. Nevertheless, a down-regulation of COX-2 expression was detected in LDL-KO trained ovariectomized when compared to LDL-KO sedentary. Our results are consistent with the notion that exercise training is able to modulate COX-2 expression in LDL-KO mice as a result of COX-2 down-regulation.

Effect of exercise training on aging-induced changes in rat papillary muscle

BACKGROUND The effects of aging on papillary muscle have been widely demonstrated, but no data on the effects of exercise on the age-related changes are available. OBJECTIVE To analyze the effects of aging on the morphological and quantitative properties of papillary muscle and investigate whether a long-term moderate exercise program would exert a protective effect against the effects of aging. METHODS We used electron microscopy to study the density of myocytes, capillaries and connective tissue and the cross-sectional area of myocytes of the papillary muscle of the left ventricle of 6- and 13-month-old untrained and exercised Wistar rats. RESULTS As expected, the volume density of myocytes declined significantly (p<0.05) with aging. The length density of myocardial capillaries also declined with aging, but not significantly. The interstitial volume fraction of the papillary muscle tissue increased significantly (P<0.05) with age. The number of myocyte profiles showed a reduction of 20% that was accompanied by myocyte hypertrophy in the aged rats (P<0.05). Animals submitted to a 60-minute daily session,, 5 days/wk at 1.8 km x h(-1) of moderate running on a treadmill for 28 weeks showed a reversion of all the observed aging effects on papillary muscle. CONCLUSION The present study supports the concept that long-term exercise training restrains the aging-related deleterious changes in the papillary muscle.FUNDAMENTO: Os efeitos do envelhecimento no musculo papilar tem sido amplamente demonstrados, mas nao ha dados disponiveis sobre os efeitos do exercicio nas alteracoes relacionadas a idade. OBJETIVO: Analisar os efeitos do envelhecimento nas propriedades morfologicas e quantitativas do musculo papilar e investigar se um programa continuo de exercicios moderados pode exercer um efeito protetor contra as consequencias do envelhecimento. METODOS: Microscopia eletronica foi utilizada para estudar a densidade dos miocitos, capilares e tecido conectivo e area transversal dos miocitos do musculo papilar no ventriculo esquerdo de ratos Wistar de 6 e 13 meses, nao-treinados e submetidos a exercicios. RESULTADOS: Como esperado, a densidade de volume dos miocitos diminui significantemente (p<0,05) com a idade. A densidade de comprimento dos capilares tambem diminui com a idade, mas nao de forma significante. A fracao de volume intersticial do tecido do musculo capilar aumenta significantemente com a idade (P<0,05). O numero de perfis de miocitos mostrou uma reducao de 20% que foi acompanhada de hipertrofia dos miocitos no envelhecimento (P<0,05). Animais submetidos a uma sessao diaria de 60 minutos, 5 dias/semana a 1,8 km.h-1 de corrida moderada em esteira ergometrica durante 28 semanas mostraram uma reversao de todos os efeitos do envelhecimento observados no musculo papilar. CONCLUSAO: O presente estudo apoia o conceito de que treinamento fisico de longo prazo impede as mudancas deleterias relacionadas a idade no musculo capilar.

Effects of moderate exercise on biochemical, morphological, and physiological parameters of the pancreas of female mice with estrogen deprivation and dyslipidemia

Menopausal women are at high risk of developing heart disease. However, physical exercise practice can reverse this scenario. We evaluated the biochemical, morphological, and physiological effects of moderate aerobic physical exercise on the pancreas of knockout mice for LDL receptor with estrogen deprivation by ovariectomy. Animals were divided into six groups (n = 5): sedentary non-ovariectomized control; sedentary ovariectomized control; trained ovariectomized control; sedentary non-ovariectomized LDL-R knockout; sedentary ovariectomized LDL-R knockout; and trained ovariectomized LDL-R knockout. Physical exercise practice promoted improvement in biometric and biochemical parameters analyzed, with reduction of visceral adipose tissue and VLDL, triglycerides, total cholesterol, and blood glucose levels. In addition, physical exercise practice altered the morphology of pancreatic islets and improved their response to the effects of menopause. Thus, physical exercise practice was fundamental to minimize the effects of dyslipidemia associated with ovariectomy in the pancreatic tissue of LDL-R knockout animals, contributing to reduce the risk of developing cardiac diseases in the menopause period.

effect of different exercise intensities on the pancreas of animals with metabolic syndrome

Introduction Metabolic syndrome (MS) comprises several metabolic disorders that are risk factors for cardiovascular disease and has its source connected to the accumulation of visceral adipose tissue (VAT) and development of insulin resistance. Despite studies showing beneficial results of exercise on several risk factors for cardiovascular disease, studies evaluating the effects of different intensities of exercise training on the pancreas with experimental models are scarce. Methods In total, 20 Wistar rats were used, divided into four groups: control (C), metabolic syndrome (MS and without exercise), metabolic syndrome and practice of walking (MSWalk), and metabolic syndrome and practice of running (MSRun). The applied procedures were induction of MS by fructose in drinking water; experimental protocol of walking and running; weighing of body mass and VAT; sacrifice of animals with blood collection and removal of organs and processing of samples for light microscopy using the analysis of volume densities (Vv) of the studied structures. Results Running showed a reduction of VAT weight (−54%), triglyceride levels (−40%), Vv[islet] (−62%), Vv[islet.cells] (−22%), Vv[islet.insterstitial] (−44%), and Vv[acinar.insterstitial] (−24%) and an increase of Vv[acini] (+21%) and Vv[acinar.cells] (+22%). Regarding walking, we observed a decrease of VAT weight (−34%) and triglyceride levels (−27%), an increase of Vv[islet.cells] (+72%) and Vv[acinar.cells] (+7%), and a decrease of Vv[acini] (−4%) and Vv[acinar.insterstitial] (−16%) when compared with those in the MS group. Conclusion Our results suggest that the experimental model with low-intensity exercise (walking) seems to be more particularly recommended for preventing morphological and metabolic disorders occurring in the MS.