Effects of swimming training on bone mass and the GH/IGF-1 axis in diabetic rats.

The aim of this study was to examine the influence of moderate swimming training on the GH/IGF-1 growth axis and tibial mass in diabetic rats. Male Wistar rats were allocated to one of four groups: sedentary control (SC), trained control (TC), sedentary diabetic (SD) and trained diabetic (TD). Diabetes was induced with alloxan (35 mg/kg b.w.). The training program consisted of a 1h swimming session/day with a load corresponding to 5% of the b.w., five days/week for six weeks. At the end of the training period, the rats were sacrificed and blood was collected for quantification of the serum glucose, insulin, GH, and IGF-1 concentrations. Samples of skeletal muscle were used to quantify the IGF-1 peptide content. The tibias were collected to determine their total area, length and bone mineral content. The results were analyzed by ANOVA with P<0.05 indicating significance. Diabetes decreased the serum levels of GH and IGF-1, as well as the tibial length, total area and bone mineral content in the SD group (P<0.05). Physical training increased the serum IGF-1 level in the TC and TD groups when compared to the sedentary groups (SC and SD), and the tibial length, total area and bone mineral content were higher in the TD group than in the SD group (P<0.05). Exercise did not alter the level of IGF-1 in gastrocnemius muscle in nondiabetic rats, but the muscle IGF-1 content was higher in the TD group than in the SD group. These results indicate that swimming training stimulates bone mass and the GH/IGF-1 axis in diabetic rats.

Serum electrolyte and total protein alterations in Pantaneiro horse during long distance exercise

Blood samples were taken from eight Pantaneiro horses during a 76km endurance ride. The horses were divided into two groups: 1- four horses kept on native pasture, without working and with no supplementation during one month before the ride, 2- four horses kept on native pasture with supplementation and submitted to work during one month before the ride. Serum concentration of total protein, albumin, sodium, potassium, chloride, calcium and phosphorus were measured. Samples were taken before the ride (preride), during the mid point (midride), at the end of the ride (postride) and after a 30-minute recovery period (rest). Sweat samples were collected from five horses at the end of the ride to measure sodium, potassium, and chloride. In both groups, there was a significant decrease in calcium and potassium, and an increase in sodium and phosphorus during the ride. Heart rate values after 30 minutes of rest indicated a good recovery response.

Foram colhidas amostras de sangue de oito cavalos Pantaneiro durante uma prova de resistência de 76km através do Pantanal. Um mês antes da prova os cavalos foram distribuídos em dois grupos: 1- quatro cavalos mantidos em pastagem nativa sem suplementação e sem trabalho; 2- quatro cavalos mantidos em pastagem nativa com suplementação e submetidos a trabalho. Amostras de sangue foram colhidas antes da prova (pré), durante (meio), ao final (pós) e após um período de recuperação de 30 minutos (descanso). Foram analisadas as concentrações séricas de proteína total (PT), albumina (Alb), sódio (Na), potássio (K), cloro (Cl), cálcio (Ca) e fósforo (P). No final da prova também foram colhidas amostras de suor de cinco cavalos para análise de Na, K e Cl. Durante a prova, houve diminuição significativa nos teores de Ca e K e aumento nos teores de Na e P em ambos os grupos. Os valores médios da taxa cardíaca após 30 minutos de descanso indicaram boa resposta de recuperação.