Effect of Dehydroepiandrosterone on Affected and Unaffected Hindlimb Muscles in Rats with Neuropathic Pain Induced by Unilateral Peripheral Nerve Injury

PURPOSE: The purpose of this study was to examine the effect of DHEA (Dehydroepiandrosterone) on muscle weight and Type I and II fiber cross-sectional area of affected and unaffected hindlimb muscles in rats with neuropathic pain induced by unilateral peripheral nerve injury. METHODS: Neuropathic pain was induced by ligation and cutting of the left L5 spinal nerve. Adult male Sprague-Dawley rats were randomly assigned to one of two groups: The DHEA group (n=10) had DHEA injections daily for 14 days, and the Vehicle group (n=10) had vehicle injections daily for 14 days. Withdrawal threshold, body weight, food intake and activity were measured every day. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected from the both hindlimbs. Body weight, food intake, activity, muscle weight and Type I, II fiber cross-sectional area of the dissected muscles were measured. RESULTS: The DHEA group showed significant increases (p<.05), as compared to the vehicle group for muscle weight of the unaffected plantaris, and in Type II fiber cross-sectional area of the gastrocnemius muscle. The DHEA group demonstrated a higher pain threshold than the vehicle group whereas total diet intake and activity score were not significantly different between the two groups. CONCLUSION: DHEA administration for 14 days attenuates unaffected plantaris and gastrocnemius muscle atrophy.

Effect of DHEA Administration Alone or Exercise combined with DHEA before Steroid Treatment on Rat Hindlimb Muscles

PURPOSE: The purpose of this study was to determine the effect of Dehydroepiandrosterone (DHEA) administration alone or exercise combined with DHEA before steroid treatment on rat hindlimb muscles. METHODS: Male Sprague-Dawley rats were assigned to one of three groups: a steroid group (S, n=10) that had no treatment for 7 days before steroid treatment; a DHEA-steroid group (DS, n=8) that had 0.34 mmol/kg/day DHEA injection once a day for 7 days before steroid treatment and an exercise?steroid group (EDS, n=9) that ran on the treadmill combined with 0.34 mmol/kg/day DHEA injection for 7 days before steroid treatment. At 15 days all rats were anesthetized and soleus, plantaris and gastrocnemius muscles were dissected. Body weight, food intake, muscle weight, myofibillar protein content and cross-sectional area of the dissected muscles were determined. RESULTS: The DS group showed significant increases (p<.05) as compared to the steroid group in body weight, and muscle weight of gastrocnemius muscles. The EDS group showed significant increases (p<.05) as compared to the S group in body weight, muscle weight, myofibrillar protein content, and Type II fiber cross-sectional area of soleus, plantaris and gastrocnemius muscles. CONCLUSION: Exercise combined with DHEA administration before steroid treatment prevents steroid induced muscle atrophy, with exercise combined with DHEA administration being more effective than DHEA administration alone in preventing muscle atrophy.

Trastornos de la conducta alimentaria como factor de riesgo para osteoporosis / Eating disorders as risk factors for osteoporosis

Los trastornos de la conducta alimentaria son comunes en mujeres jóvenes con una prevalencia estimada de entre 4-5 por ciento. La pérdida de masa ósea es una complicación física de la anorexia nervosa y trastorno alimentario no especificado que afecta tanto a hueso cortical como trabecular. El efecto sinérgico de la desnutrición y la deficiencia de estrógenos produce una pérdida de masa ósea a través del desacoplamiento entre resorción osteoclástica y formación osteoblástica. La severidad varía dependiendo de la duración de la enfermedad, el peso menor alcanzado y la actividad física. La repercusión a largo plazo es evidente pues existe un incremento en el riesgo de fractura en las pacientes que han padecido anorexia nervosa. La primera línea de tratamiento para recuperar la masa ósea es la rehabilitación nutricia y un incremento de peso. La terapia de reemplazo hormonal podría ser efectiva si se combina con métodos anabólicos. Los términos osteopenia y osteoporosis fueron adoptados para definir la deficiencia de masa ósea en adultos. Los autores de las publicaciones que fueron revisadas utilizaron dichos términos para definir datos densitométricos en sujetos jóvenes que no han alcanzado la masa ósea pico. Sugerimos el término "hipo-osteogenesia" para definir el desarrollo deficiente de masa ósea en adolescentes o niños.