Tratamento neonatal com aloxana em ratos: efeitos do exercício
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Data
2004-08-03
Autores
Oliveira, Camila Aparecida Machado de [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O exercício físico tem sido recomendado na prevenção do diabetes mellitus não insulino dependente (NIDDM), mas os mecanismos envolvidos nessa intervenção ainda não são bem conhecidos. Modelos experimentais oferecem oportunidade para o estudo dessa questão. Ratos tratados com streptozotocina no período neonatal têm sido empregados como modelo de NIDDM, porém, pouco se sabe sobre o modelo de diabetes neonatal induzido por aloxana. Com o objetivo de analisar os efeitos metabólicos da administração neonatal de aloxana, ratos recém nascidos (2 e 4 dias), de ambos os sexos, receberam a droga (200 mg/Kg p.c.-i.p.). Como controles foram utilizados ratos injetados com veículo (tampão citrato). Aos 28, 60 e 90 dias de idade os animais foram avaliados quanto a: glicemia de jejum, glicemia após administração de glicose e tolerância à glicose oral (GTTo). Os resultados mostraram maior glicemia no GTTo (p>0,05) até os 60 dias nos grupos tratados com a droga, regredindo aos 90 dias em ambos os sexos. Aos 90 dias os animais foram sacrificados por decapitação. Ficou evidente que os machos que receberam a aloxana aos dois dias foram os mais prejudicados, mostrando os menores teores de insulina e razão proteína/DNA pancreáticos e os níveis mais elevados de A.G.L. sangüíneo (p<0,05). Concluindo, embora a intolerância à glicose seja transitória, a recuperação dos animais é incompleta, pois algumas alterações metabólicas persistem. Em outra série de experimentos, visando avaliar os efeitos do treinamento aeróbio sobre a manifestação das alterações metabólicas causadas pela aloxana, ratos recém nascidos (2 dias) receberam aloxana (200 mg/Kg de peso corporal) via intraperitoneal. Como controles foram utilizados ratos injetados com veículo (tampão citrato)... (Complete abstract, click electronic address below).
The present study was designed to analyse the metabolic effects of neonatal alloxan administration. Male and female newborn rats (2 and 4 days old) received alloxan (200 mg/Kg b.w.-i.p.). Vehicle injected rats were used as control. At 28, 60 and 90 days old the animals were evaluated with respect to: fasting glycemia, non-fasting glycemia and oral glucose tolerance (GTTo). The results showed higher glycemia during the GTTo (p>0,05) in the alloxan injected rats than in controls at the 60th day old, but not at the 90th day. At 90 days old, the animals were sacrified by decapitation. It was clearly demonstrated that the male rats receiving alloxan at the 2nd day of life were the most affected by the drug. They showed the lowest pancreatic insulin content and protein/DNA ratio and the highest serum F.F.A. levels (p<0,05). In conclusion, although the glucose intolerance is transitory, the animals rehabilitation is incomplete, since some metabolic alterations remain. In another series of experiment, to analyse the effects of aerobic physical training on the manifestation of the metabolic effects of alloxan, male newborn rats (2 days old) received alloxan (200 mg/Kg b.w.) intraperitoneally. Vehicle injected rats (citrate buffer) were used as control. After weaning, part of the alloxan treated rats were submitted to 1-h day-1, 5-day week-1 swimming, with an overload equivalent to 3% of the body weight. At 28, 60 and 90 days old the animals were submitted to a glucose (GTTo) and insulin (ITTsc) tolerance test. Forty eight hours after the last tolerance test, and to the trained animals, 48 hours after the last training, the animals were sacrificed by decapitation. Although the hyperglycaemia is transitory in the sedentary alloxan treated animals, some alterations remain: high serum F.F.A. levels, low pancreatic insulin content; which can be harmful to homeostasis maintenance. The rehabilitation... (Complete abstract, click electronic address below).
The present study was designed to analyse the metabolic effects of neonatal alloxan administration. Male and female newborn rats (2 and 4 days old) received alloxan (200 mg/Kg b.w.-i.p.). Vehicle injected rats were used as control. At 28, 60 and 90 days old the animals were evaluated with respect to: fasting glycemia, non-fasting glycemia and oral glucose tolerance (GTTo). The results showed higher glycemia during the GTTo (p>0,05) in the alloxan injected rats than in controls at the 60th day old, but not at the 90th day. At 90 days old, the animals were sacrified by decapitation. It was clearly demonstrated that the male rats receiving alloxan at the 2nd day of life were the most affected by the drug. They showed the lowest pancreatic insulin content and protein/DNA ratio and the highest serum F.F.A. levels (p<0,05). In conclusion, although the glucose intolerance is transitory, the animals rehabilitation is incomplete, since some metabolic alterations remain. In another series of experiment, to analyse the effects of aerobic physical training on the manifestation of the metabolic effects of alloxan, male newborn rats (2 days old) received alloxan (200 mg/Kg b.w.) intraperitoneally. Vehicle injected rats (citrate buffer) were used as control. After weaning, part of the alloxan treated rats were submitted to 1-h day-1, 5-day week-1 swimming, with an overload equivalent to 3% of the body weight. At 28, 60 and 90 days old the animals were submitted to a glucose (GTTo) and insulin (ITTsc) tolerance test. Forty eight hours after the last tolerance test, and to the trained animals, 48 hours after the last training, the animals were sacrificed by decapitation. Although the hyperglycaemia is transitory in the sedentary alloxan treated animals, some alterations remain: high serum F.F.A. levels, low pancreatic insulin content; which can be harmful to homeostasis maintenance. The rehabilitation... (Complete abstract, click electronic address below).
Descrição
Palavras-chave
Patologia, Exercícios físicos, Diabetes, Aloxana, Treinamento físico
Como citar
OLIVEIRA, Camila Aparecida Machado de. Tratamento neonatal com aloxana em ratos: efeitos do exercício. 2004. 82 f. Dissertação (mestrado) - Universidade Estadual Paulista, Instituto de Biociências de Rio Claro, 2004.