Differential nutritional, endocrine, and cardiovascular effects in obesity-prone and obesity-resistant rats fed standard and hypercaloric diets

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

Growth hormone attenuates skeletal muscle changes in experimental chronic heart failure

Objective: This study evaluated the effects of growth hormone (GH) on morphology and myogenic regulatory factors (MRF) gene expression in skeletal muscle of rats with ascending aortic stenosis (AAS) induced chronic heart failure.Design: Male 90-100 g Wistar rats were subjected to thoracotomy. AAS was created by placing a stainless-steel clip on the ascending aorta. Twenty five weeks after surgery, rats were treated with daily subcutaneous injections of recombinant human GH (2 mg/kg/day; AAS-GH group) or saline (AAS group) for 14 days. Sham-operated animals served as controls. Left ventricular (LV) function was assessed before and after treatment. IGF-1 serum levels were measured by ELISA. After anesthesia, soleus muscle was frozen in liquid nitrogen. Histological sections were stained with HE and picrosirius red to calculate muscle fiber cross-sectional area and collagen fractional area, respectively. MRF myogenin and MyoD expression was analyzed by reverse transcription PCR.Results: Body weight was similar between groups. AAS and AAS-GH groups presented dilated left atrium, left ventricular (LV) hypertrophy (LV mass index: Control 1.90 +/- 0.15; AAS 3.11 +/- 0.44; AAS-GH 2.94 +/- 0.47 g/kg; p < 0.05 AAS and AAS-GH vs. Control), and reduced LV posterior wall shortening velocity. Soleus muscle fiber area was significantly lower in AAS than in Control and AAS-GH groups; there was no difference between AAS-GH and Control groups. Collagen fractional area was significantly higher in MS than Control; AAS-GH did not differ from both Control and AAS groups. Serum IGF-1 levels decreased in AAS compared to Control. MyoD mRNA was significantly higher in AAS-GH than AAS; there was no difference between AAS-GH and Control groups. Myogenin mRNA levels were similar between groups.Conclusion: In rats with aortic stenosis-induced heart failure, growth hormone administration increases MyoD gene expression above non-treated animal levels, preserves muscular trophism and attenuates interstitial fibrosis. These results suggest that growth hormone may have a potential role as an adjuvant therapy for chronic heart failure. (C) 2009 Elsevier Ltd. All rights reserved.

Perfil nutricional e cardiovascular de ratos normotensos e hipertensos sob dieta hiperlipídica

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

Effect of cyclosporine on adriamycin induced nephritis

The effects of cyclosporine A (CSA) administration, started as early as renal lesion is induced, on the development of Adriamycin-induced nephropathy were assessed by comparing the time course of this nephropathy in rats receiving CSA with that in non-treated animals (group ADR) over 16 weeks. Throughout the experiment, no significant difference in proteinuria was observed between the groups. At the end of the experiment, there was no significant difference between the groups regarding the frequency of glomerular lesion (Group AADR: Md=23%, P25=15%, P75=75%; Group ADR-CSA: Md=48%, P25=11%, P75=70%); tubulointerstitial lesion index (Group ADR: Md=1.5, P25=1.0, P75=2.5); glomerulosclerosis area (Group ADR = 18.2 +/- 4.2%; Group ADR-CSA = 13.2 +/- 1.4%); and, interstitial fibrosis area (Group ADR+V: 1.75 +/- 0.10%; group ADR-CSA: 1.34 +/- 0.09%). In conclusion, CSA, when, administered since nephropathy induction does not change the course of the disease.

Criteria for the diagnosis of diffuse uterine myohypertrophy

Objectives: Diffuse uterine myohypertrophy (DUMH) is a condition clinically diagnosed by the presence of uterine bleeding, homogeneous and diffuse uterine enlargement, and absence of any myoendometrial cause of bleeding. Since the morphologic criteria for the diagnosis of this entity are still controversial, this study aimed to investigate the clinical presentation and the morphologic findings of the cases of DUMH presenting at the University Hospital of Botucatu, São Paulo, Brazil, Methods: We retrospectively studied 43 consecutive patients with DUMH submitted to hysterectomy (test group) and compared the findings with those obtained from 28 patients submitted to hysterectomy due to a prolapsed uterus (control group). There were no significant differences in age, weight or height between the two groups. Results: the uterine weight of the DUMH group (mean +/- S.D. 157.4 +/- 46.4 g) was significantly heavier than that of the control group (99.5 +/- 35.4 g) and myometrial thickness was significantly greater in the DUMH group (2.5 +/- 0.5 cm) than in the control group (1.9 +/- 0.4 cm). No positive correlation was observed between increased uterine weight and parity, but there was a positive correlation between uterine weight and myometrial thickness. on the basis of the present study, we suggest that the diagnosis of DUMH be made clinically and in cases of uterine weight greater than or equal to 120 g and myometrial thickness greater than or equal to 2.0 cm. In addition, 10 cases of each group were analyzed by morphometry to evaluate interstitial fibrosis and myometrial hypertrophy. The data showed that the increase in uterine weight in DUMH is caused by enlargement of individual myometrial fibers rather than accumulation of interstitial collagen. Conclusion: Discriminant analysis to estimate the diagnostic significance of a number of clinical and pathologic variables (age, parity, uterine weight and morphometric parameters) was able to differentiate cases of DUMH from controls in 100% of the patients.

Importance of early and continuous use of protein restriction on the progression of adriamycin nephropathy

Three experimental protocols were carried out with the aim of evaluating the role of protein restriction on the progression of the established adriamycin-induced nephropathy, and whether the protective effect of the diet persists after the diet is discontinued. The effect of a low protein diet (LPD) was studied for 6 weeks in protocol 1, 16 weeks in protocol 2 and for 28 weeks in protocol 3. In protocol 3, one group (LL) received LPD and another (NN) was given a normal protein diet (NPD). A third group (LN) received LPD for 16 weeks and then NPD for 12 weeks and a fourth group (NL) was fed NPD for 16 weeks and then LPD for 12 weeks. In protocol I the tubulo- interstitial index (TILl) of rats on LPD (Md = 2, P25 = 0.0; P75 = 3.5) after six weeks, was smaller than that of the animals on NPD (Md = 6.0; P25 = 3.0; P75 = 8.0; p < 0.05). In protocol 2, the group taking LPD presented an area of interstitial fibrosis (IF) (Md= 0.5%, P25 0.2%; P75 = 1.9%) smaller than that of the NPD group (Md = 6.8%; P25 = 5.2%; P75 = 7.1%; P < 0.05). No significant difference in the area of glomerulosclerosis (GSA) was observed between the animals on LPD (Md = 0.0%; P25 = 0.0%, P75 = 0.0%) and NPD (Md = 0.37%; P25 = 02% P75 = 1.25%; p > 0.05). In protocol 3, the group LL showed GSA (Md = 1.3%; P25 0.6%, P75 = 2.5%) and IF (Md = 3.60/0; P25 = 1.6%; P75 = 5.9%) smaller that those of LN (GSA Md = 10.1%; P25 = 6.6%; P75 = 14.8%; IF; Md = 17.3%; P25 = 14.1%; P75 = 24,5%), NL (GSA: Md = 9.1%; P25 = 5,8%; P75 = 11.7%; IF; Md = 25.0%; P25 = 20.4%; P75 = 30%), and NN (GSA: Md = 6. 75%; P25 = 4.9%; P75 = 11.7%; IF: Md = 20.9%; P25 = 16.2%; P75 = 32.4%). In conclusion, in order to be effective, LPD must be introduced early and maintained for a long period of tune.

Doxorubicin induced dilated cardiomyopathy in a rabbit model: An update

Dilated cardiomyopathy (DCM) is characterized by chamber dilation and cardiac dysfunction. Because of the poor prognosis, models are needed for the investigation of and development of new therapeutic approaches, as well as stem cell therapy. Doxorubicin (DOX), used as chemotherapeutic agent, is reported to be cumulative cardiotoxic causing DCM. The aim of the study was to investigate the onset of systolic dysfunction using echocardiography in rabbits receiving two different doses of DOX (1. mg/kg twice a week and 2. mg/kg once a week). Twenty rabbits were treated with doxorubicin in two different doses for 6. weeks and compared with a control group treated with NaCl 0.9%. The effect of doxorubicin on the myocardium was investigated with histological analysis and scanning electron microscopy of left ventricle (LV), as well as in the interventricular septum (IVS) and right ventricle (RV). The results showed a high mortality rate for rabbits receiving 2. mg/kg once a week. A significant reduction in systolic function was present in animals treated with DOX after 6. weeks, with decreased ejection fraction and shortening fraction. Histology and electron microscopy revealed vacuolization, intracytoplasmic granulation, necrosis and interstitial fibrosis in LV, as well as in the IVS and RV. Doxorubicin induced changes are present in the LV, RV and IVS, and the administration at the dose of 1. mg/kg twice a week for only 6. weeks is safe and sufficient to induce DCM in rabbits. © 2012 Elsevier Ltd.

Treatment of adriamycin-induced nephropathy with erythropoietin and G-CSF

Background: Granulocyte colony-stimulating factor (G-CSF) and Erythropoietin (EPO) are known to stimulate the growth and differentiation of progenitor cells to prevent acute renal injury. This study aimed to assess the use of growth factors to mobilize stem cell in a mouse model of adriamycin-induced chronic kidney disease. Methods: All animals were injected with adriamycin for kidney injury and allocated into three treatment groups (G-CSF, EPO and G-CSF + EPO), and a control group (adriamycin alone). Results: Number of atrophic sites, glomerulosclerosis rate and interstitial fibrosis severity score were assessed in all groups. In all treatment groups, histologic parameters did not significantly differ, but were lower than in the control group (P<.001). Scal and CD34 expressions among treatment groups showed no statistically significant difference, but were higher than in the control group (P<.0001). CD105 expression was higher in EPO and G+EPO as compared to G-CSF and the control group (P<.0001), with no statistically significant difference between the latter two groups (P = NS). Conclusion: G-CSF and EPO had a histologic protective effect, while treatment with EPO + G-CSF had no additive effects in a model of adriamycin-induced chronic kidney disease. © 2013 Societá Italiana di Nefrologia.

Pulmonary and hepatic lesions caused by the dehydropyrrolizidine alkaloid-producing plants Crotalaria juncea and Crotalaria retusa in donkeys

The effects and susceptibility of donkeys to Crotalaria juncea and Crotalaria retusa poisoning were determined at high and low doses. Seeds of C. juncea containing 0.074% of dehydropyrrolizidine alkaloids (DHPAs) (isohemijunceines 0.05%, trichodesmine 0.016%, and junceine 0.008%) were administered to three donkeys at 0.3, 0.6 and 1g/kg body weight (g/kg) daily for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was a mild liver megalocytosis in the donkeys ingesting 0.6 and 1g/kg/day. Two other donkeys that received daily doses of 3 and 5g seed/kg showed initial respiratory signs 70 and 40 days after the start of the administration, respectively. The donkeys were euthanized following severe respiratory signs and the main lung lesions were proliferation of Clara cells and interstitial fibrosis. Three donkeys ingested seeds of C. retusa containing 5.99% of monocrotaline at daily doses of 0.025, 0.05 and 0.1g/kg for 365 days. No clinical signs were observed and, on liver and lung biopsies, the only lesion was moderate liver megalocytosis in each of the three donkeys. One donkey that received a single dose of 5g/kg of C. retusa seeds and another that received 1g/kg daily for 7 days both showed severe clinical signs and died with diffuse centrilobular liver necrosis. No lung lesions were observed. Another donkey that received a single dose of 2.5g/kg of C. retusa seeds showed no clinical signs. The hepatic and pneumotoxic effects observed are consistent with an etiology involving DHPAs. Furthermore, the occurrence of lung or liver lesions correlates with the type of DHPAs contained in the seeds. Similarly as has been reported for horses, the data herein suggest that in donkeys some DHPAs are metabolized in the liver causing liver disease, whereas others are metabolized in the lung by Clara cells causing lung disease. © 2013 Elsevier Ltd.

Influência da obesidade sobre a composição de cadeias pesadas de Miosina e Fibrose intersticial miocárdica de ratos normotensos e espontaneamente hipertensos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Alterações hemodinâmicas e cardíacas de pacientes com cirrose hepática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência do antioxidante quercetina sobre a remodelação cardíaca e a atividade oxidativa de ratos com Diabetes mellitus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The role of renin-angiotensin system in the chronic allograft nephropathy: an immunohistochemical study

Evidences suggest a role of renin-angiotensin system (RAS) in the development of chronic allograft injury. We correlated intrarenal angiotensin-converting enzyme, angiotensin II (Angio II) and transforming growth factor β1 (TGFβ1) expression in 58 biopsies-proven chronic allograft nephropathy (CAN) with tissue injury and allograft survival. The biopsies with CAN were graded according to Banff classification as I (22 cases), II (17) and III (19); 27 biopsies also showed a mononuclear inflammatory infiltrate in scarred areas. There were increased expression of angiotensin converting-enzyme (ACE), Angio II and TGFβ1 mainly in tubulointerstitial compartment in the group with CAN; there was no association of Angio II and TGFβ1 expression with interstitial fibrosis. There were no significant differences of ACE, Angio II and TGFβ1 expression between the patients treated and untreated with RAS blockade, and with the graft outcome. Interstitial inflammatory infiltrate had positive correlation with interstitial fibrosis and significant impact on graft survival at 8 years. Our study showed in a group of cases with CAN a high percentage of inflammatory infiltrate that correlated with interstitial fibrosis and graft outcome. The chronic inflammatory changes in these cases did not show significant association with local RAS expression.

Avaliação dos efeitos do carvedilol, ciclosporina A e citrato de sildenafil sobre a cardiotoxicidade induzida pela doxorrubicina em modelo experimental com coelhos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Antifibrotic Effect of Tamoxifen in a Model of Progressive Renal Disease

Tamoxifen, a selective estrogen receptor modulator, has antifibrotic properties; however, whether it can attenuate renal fibrosis is unknown. In this study, we tested the effects of tamoxifen in a model of hypertensive nephrosclerosis (chronic inhibition of nitric oxide synthesis with L-NAME). After 30 days, treated rats had significantly lower levels of albuminuria as well as lower histologic scores for glomerulosclerosis and interstitial fibrosis than untreated controls. Tamoxifen was renoprotective despite having no effect on the sustained, severe hypertension induced by L-NAME. Tamoxifen prevented the accumulation of extracellular matrix by decreasing the expression of collagen I, collagen III, and fibronectin mRNA and protein. These renoprotective effects associated with inhibition of TGF-beta 1 and plasminogen activator inhibitor-1, and with a significant reduction in a-smooth muscle actin-positive cells in the renal interstitium. Furthermore, tamoxifen abrogated IL-1 beta- and angiotensin-II-induced proliferation of fibroblasts from both kidney explants and from the NRK-49F cell line. Tamoxifen also inhibited the expression of extracellular matrix components and the production and release of TGF-beta 1 into the supernatant of these cells. In summary, tamoxifen exhibits antifibrotic effects in the L-NAME model of hypertensive nephrosclerosis, likely through the inhibition of TGF-beta 1, suggesting that it may have therapeutic use in CKD treatment.