Immunohistochemical analysis of the XXXX psoas major muscle with regards to the body side and aging.

@entity1 @entity194
The aim of our study was to explore the age related changes of the fibre type composition of the @entity1 psoas major muscle. Moreover, we wanted to compare the fibre type composition of the left and right muscle. Muscle samples were collected from 15 young and 15 old males. Type I, IIA and IIX muscle fibres were typed using myosin heavy chain identification. The serial transverse sections were analysed using a light microscope. Results of our study showed that the age-related @entity194 affected all three fibre types. Type IIA fibres were affected most profoundly while type I fibres were affected most weakly. The percentage of the different fibre types did not change during aging. There were no differences in the fibre type composition between the left and right muscle. @entity1 psoas major muscle undergoes normal aging changes with the @entity194 of all three fibre types, whereas @entity194 most profoundly affects type IIA fibres. No differences in the fibre type composition between the left and right muscle point to the equal engagement of both legs in normal everyday activities of @entity1 .
