Acid hydrolase activity in tissues of mice after physical stress

The activities of beta-glucuronidase and cathepsin D and the protein concentration were assayed from brain, kidney, liver, cardiac muscle and skeletal muscle (m. rectus femoris) samples from mice (Mus musculus) 1, 3, and 6 days after intermittent exhaustive (duration 100-145 min) and submaximal prolonged (duration 9 hr) running on treadmill. The activity of beta-glucuronidase in skeletal muscle strongly increased being the highest 3 days after both exertions. Cathepsin D activity also slightly increased. In cardiac muscle beta-glucuronidase activity was unaffected. Cathepsin D activity slightly increased 3 days after intermittent exhaustive exercise. The specific activities of beta-glucuronidase and cathepsin D in the liver increased 1 day after the both exertions. Simultaneously the protein concentration decreased. In the kidney beta-glucuronidase activity and protein concentration were unaffected but cathepsin D activity decreased 1 day after intermittent exhaustive exercise. In the brain protein concentration transiently decreased 3 days after the exertions. beta-Glucuronidase activity transiently decreased 1 day after intermittent exercise thereafter increasing 6 days afterwards above the control level. Cathepsin D activity decreased 1 day after intermittent exercise but was unaffected after prolonged submaximal exercise. Physical stress affected to varying extent the acid hydrolase activities in all organs studied.