More Resistant Tendons Obtained from the Association of Heteropterys aphrodisiaca and Endurance Training

• Grant number: 11/09754-2
• Support Opportunities: Regular Research Grants - Publications - Scientific article
• Start date: July 01, 2011
• End date: December 31, 2011
• Field of knowledge: Biological Sciences - Morphology - Cytology and Cell Biology
• Principal Investigator: Mary Anne Heidi Dolder
• Grantee: Mary Anne Heidi Dolder
• Host Institution: Instituto de Biologia (IB). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil

Abstract

Objective: To investigate the effects of Heteropterys aphrodisiaca infusion on the tendon properties and extracellular matrix of rats under endurance training.Methods: Wistar rats were grouped as follows: CS- control sedentary, HS- H. aphrodisiaca sedentary, CT-control trained, HT- H. aphrodisiaca trained. The training protocol consisted in running on a motorized treadmill, five times a week, with weekly increase in treadmill velocity and duration of 11 weeks, consisting in 3 weeks of adaptation and 8 weeks of training. Control groups received water while the HS and HT groups received H. aphrodisiaca infusion (dose: 35 mg/animal/day) daily by gavage for the 8 weeks of training. Achilles tendons were frozen for biochemical and biomechanical analysis or preserved in Karnovsky's fixative, then processed for histomorphological analysis by conventional and polarized light microscopy.Results: The noncollagenous protein levels diminished in the animals of CT group, confirming the data of SDS-PAGE analysis. The hydroxyproline content increased in the HT group. Biomechanical analysis showed significant increase in maximum stress and modulus of elasticity of the tendons of the HT animals. The MMP-2 activity trended to be reduced in the HT group. The compression region of tendons of HT animals had a stronger and more intense metachromasy, which suggests increase in glycosaminoglycan concentration in this region of the tendon, although the sulfated glycosaminoglycan levels were statistically similar among the four groups. The most intense birefringence was observed in both compression and tension regions of the tendon of HT animals, which may indicate a higher organizational level of collagen bundles.Conclusion: The association of endurance training with H. aphrodisiaca resulted in stronger and better-prepared tendons to support high loads from intense muscle contraction. This association stimulated tendon remodeling, promoting higher collagen content and probably increased cross-links. Despite the clear anabolic effects of Heteropterys aphrodisiaca and the endurance exercise association, no side effects were observed, such as those found for synthetic anabolic androgenic steroids. (AU)