Estereologia do miocárdio de ratos jovens e idosos Stereology of the myocytes in young and aged rats

OBJETIVO: Comparar as diferenças quantitativas na composição e estrutura do miocárdio de ratos jovens e idosos utilizando a estereologia. MÉTODOS: Foram estudados 30 ratos machos da raça Wistar (15 animais jovens de 3 meses de idade e 15 animais idosos de 15 meses). Os corações foram retirados, pesados, perfundidos com solução de Bouin e posteriormente fixados em formol tamponado a 10% por 24h, processados por técnica histológica, incluídos em parafina, seccionados e corados pelo HE e picro-sirius. Foram analisados 15 campos aleatórios por grupo e foram determinados os seguintes parâmetros estereológicos: densidade de volume do miócito (Vv[miócito]) e densidade de volume do interstício cardíaco (Vv[interstício]) e densidade numérica dos miócitos (Nv[miócito]) (1/mm³), estimados pelo método disector. O número total de miócitos (N[miócitos]) e a média do volume do miócito (Vol[miócito]) dos corações dos dois grupos também foram determinados. As diferenças estatísticas entre os animais jovens e idosos foram testadas pelo teste não paramétrico de Mann-Whitney. RESULTADOS: Comparando os animais dos grupos jovem e idoso temos, respectivamente, os seguintes dados: o peso cardíaco aumentou de 1,1 para 1,7g, o Vv(miócito) diminuiu de 76,7 para 72,2%, Vv(interstício) aumentou de 23,3 para 27,8%, enquanto o Nv(miócito) diminuiu de 14,76x10(4) para 6,19x10(4)/mm³. O Vol(miócito) aumentou de 5,42x10³ para 13,26x10³mm³ e o N(miócito) diminuiu de 15,64x10(4) para 10,72x10(4) miócitos. Estas diferenças foram estatisticamente significativas (p<0,05). CONCLUSÃO: Os resultados obtidos mostram que no envelhecimento ocorre perda de miócitos cardíacos e hipertrofia das células remanescentes.<br>PURPOSE: To determine the myocardial quantitative changes comparing young and aged animals by using the stereology. METHODS: Thirty rat hearts were studied (15 rats aged 3 months and 15 other rats aging 15 months). The hearts were removed, weighed, fixed in 10% buffered formaldehyde solution, embedded in paraffin, cut in 7µm thick slices and stained with HE and picro-sirius stains. In each group we counted 15 random microscopic fields. The following parameters were studied: Vv(myocyte) and Vv(interstitium)(%) (the volume densities of the cardiac myocyte and interstitium, determined by the point-counting method), and Nv(myocyte) (1/mm³) (the numerical density of the cardiac myocytes, determined with the disector method). The total number of myocytes (N[myocyte]) and the mean volume of the myocytes (V[myocytes]) were also determined. The differences were tested by the Mann-Whitney test.RESULTS: Cardiac weight increased from 1.1 to 1.7g, the Vv(myocyte) decreased from 76.7 to 72.2%, the Vv(interstitium) increased from 23.3 to 27.8%. The Nv(myocyte) and the N(myocyte) decreased from 14.76x10(4) to 6.19x10(4)/mm³ and 15.64x10(4) to 10.72x10(4) myocytes, respectively. Simultaneously, the V(myocyte) increased from 5.42x10³ to 13.26x10³mm³. These differences were statistically significant (p<0.05). CONCLUSION: Myocardial changes, comparing young rats with aged ones suggest loss of myocytes (increased apoptosis?) with simultaneous myocyte hypertrophy

Lipid metabolism in rats fed diets containing different types of lipids

OBJECTIVE: To assess the effect of different types of lipid diets on the lipid metabolism of aging rats. METHODS: Fifty male Wistar rats were studied from the time of weaning to 12 and 18 months of age. Their diets were supplemented as follows: with soybean oil (S), canola oil (CA), lard and egg yolk (LE), and canola oil + lard and egg yolk (CA + LE). Blood pressure (BP) was measured every month, and the heart/body ratio (H/BR) was determined. The rats were euthanized at the age of 12 and 18 months, and blood samples were collected for lipid analysis as follows: total cholesterol (TC), LDL-C, VLDL-C, HDL-C, triglycerides (TG), and glucose. RESULTS: The type of oil ingested by the animals significantly altered BP, H/BR, and serum lipid levels in rats at 12 and 18 months. No difference was observed in the survival curve of the animals in the different groups. The LE group had the highest BP, and the CA group was the only one in which BP did not change with aging. A reduction in the H/BR was observed in the LE and CA+LE animals. At the age of 12 months, differences in TC, HDL-C, LDL-C, VLDL-C, TG, and glucose were observed. At the age of 18 months, a significant difference in TC, HDL-C, and glucose was observed. The highest TC value was found in the CA group and the lowest in the S group. CONCLUSION: No increase in BP occurred, and an improvement was evident in the lipid profile of rats fed a diet supplemented with CA, in which an elevation in HDL-C levels was observed, as compared with levels with the other types of diet

TRATAMENTO FARMACOLÓGICO REVERTE REMODELAMENTO ULTRAESTRUTURAL PANCREÁTICO ADVERSO E RESISTÊNCIA À INSULINA EM CAMUNDONGOS C57BL/6 ALIMENTADOS COM DIETA HIPERLIPÍDICA

O pâncreas sofre remodelamento estrutural em animais submetidos à sobrecarga alimentar hiperlipídica. Objetivo: Avaliar os efeitos de monoterapias e associações medicamentosas sobre o metabolismo de carboidratos e ultraestrutura pancreática num modelo experimental de síndrome metabólica (SM). Métodos: Camundongos C57BL/ 6 de 3 meses de idade receberam dieta hiperlipídica (60% lipídios) ou dieta padrão (10% lipídios) por 10 semanas, sendo, então, iniciado tratamento farmacológico, oito grupos experimentais foram formados: SC (dieta padrão, sem tratamento); HF (dieta hiperlipídica, sem tratamento); HF-T (HF+Telmisartana, 9mg%); HF-S (HF+Sitagliptina, 1,1g%); HF-M (HF+Metformina, 600 mg%) e as associações HF-TM, HF-TS e HF-SM. O tratamento durou 6 semanas. A presença de esteatose pancreática foi avaliada por microscopia eletrônica de transmissão e a insulinemia por radioimunoensaio. Os índices Homa-IR e Homa-B foram também calculados. Resultados: A dieta HF resultou em sobrepeso nos animais após duas semanas de administração quando comparado ao grupo SC, condição que foi mantida ao longo de todo o experimento (p<0,0001). Os índices Homa-IR (avalia a resistência à insulina) e HOMA-B (avalia a hipersecreção das ilhotas) encontraram-se aumentados no grupo HF (p<0,0001). Todos os tratamentos resultaram em normalização da insulinemia e redução da resistência à insulina. A microscopia eletrônica revelou citoarquitetura preservada e ausência de esteatose nos grupos tratados, enquanto o grupo HF apresentou células desorganizadas e gotículas de gordura no interior dos ácinos. Conclusão: Os tratamentos propostos foram eficazes ao tratar a resistência à insulina, promovendo insulinemia normal e redução da esteatose pancreática num modelo experimental de SM. Apoio: CNPq, Faperj

High fat diet has a prominent effect upon the course of chronic schistosomiasis mansoni in mice

This study investigated whether a long-term high-fat diet has an effect on the outcome of chronic murine schistosomiasis mansoni compared to a standard diet. Swiss Webster female mice (3 weeks old) were fed each diet for up to six months and were then infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring total serum cholesterol and body mass. Infected mice were examined 6-17 weeks post infection to estimate the number of eggs in faeces. Mice were euthanised the next day. Total serum cholesterol was lower in infected mice in comparison to uninfected controls (p = 0.0055). In contrast, body mass (p = 0.003), liver volume (p = 0.0405), spleen volume (p = 0.0124), lung volume (p = 0.0033) and faecal (p = 0.0064) and tissue egg density (p = 0.0002) were significantly higher for infected mice fed a high-fat diet. From these findings, it is suggested that a high-fat diet has a prominent effect on the course of chronic schistosomiasis mansoni in mice

High fat diet has a prominent effect upon the course of chronic schistosomiasis mansoni in mice

Submitted by Sandra Infurna ([email protected]) on 2018-09-24T15:52:48Z No. of bitstreams: 1 renatah_neves_etal_IOC_2009.pdf: 570687 bytes, checksum: 6315cd7d245227d964f94c5b3afce860 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2018-09-24T16:02:21Z (GMT) No. of bitstreams: 1 renatah_neves_etal_IOC_2009.pdf: 570687 bytes, checksum: 6315cd7d245227d964f94c5b3afce860 (MD5)Made available in DSpace on 2018-09-24T16:02:21Z (GMT). No. of bitstreams: 1 renatah_neves_etal_IOC_2009.pdf: 570687 bytes, checksum: 6315cd7d245227d964f94c5b3afce860 (MD5) Previous issue date: 2009Universidade do Estado do Rio de Janeiro. Centro Biomédico. Faculdade de Ciências Médicas. Departamento de Microbiologia, Imunologia e Parasitologia. Laborartório de Helmintologia Romero Lascasas Porto. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Helmintos Parasitos de Vertebrados. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Laboratório de Morfometria e Morfologia Cardiovascular. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Instituto de Biologia. Laboratório de Morfometria e Morfologia Cardiovascular. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Helmintos Parasitos de Vertebrados. Rio de Janeiro, RJ, Brasil.Universidade do Estado do Rio de Janeiro. Centro Biomédico. Faculdade de Ciências Médicas. Departamento de Microbiologia, Imunologia e Parasitologia. Laborartório de Helmintologia Romero Lascasas Porto. Rio de Janeiro, RJ, Brasil.This study investigated whether a long-term high-fat diet has an effect on the outcome of chronic murine schistosomiasis mansoni compared to a standard diet. Swiss Webster female mice (3 weeks old) were fed each diet for up to six months and were then infected with 50 Schistosoma mansoni cercariae. Their nutritional status was assessed by monitoring total serum cholesterol and body mass. Infected mice were examined 6-17 weeks post infection to estimate the number of eggs in faeces. Mice were euthanised the next day. Total serum cholesterol was lower in infected mice in comparison to uninfected controls (p = 0.0055). In contrast, body mass (p = 0.003), liver volume (p = 0.0405), spleen volume (p = 0.0124), lung volume (p = 0.0033) and faecal (p = 0.0064) and tissue egg density (p = 0.0002) were significantly higher for infected mice fed a high-fat diet. From these findings, it is suggested that a high-fat diet has a prominent effect on the course of chronic schistosomiasis mansoni in mice