Cytochemicai and Immunocytochemical Demonstration of Acetylcholinesterase of the Prenatal Rat Lower Limb
Yuichi Umezu, Hajime Ogata (University of Occupational Environmental Health, Kitakyushu, Japan)
Abstract: Acetylcholinesterase (AChE) activities in the prenatal rat lower limbs were investigated by both cytochemistry and immunocytochemistry.
Results indicate that the epidermal cells show immunoreactions of AChE at a limited stage at prenatal day 15, and mesenchymal cells which are occasionally in contact with the basal lamina or with the adjacent myotubes begin to show AChE activities at prenatal day 17. Such AChE-positive mesenchymal cells, involved in the formation of the muscular tissues, have almost disappeared in the subepidermis by prenatal day 19.
This suggests that AChE independent of the neuromuscular system may be involved in the mesenchymal cell differentiation especially in the inductive process during myogenesis.
A NEW METHOD FOR MEASUREMENT OF STIFFNESS IN HUMAN CALF MUSCLE
Hidetoshi Takahashi , Gunnar Grimby, Ulla Svantesson, Ulrika Osterberg (Dept. of Rehabilitation Medicine Goeteborg University, Goeteborg, Sweden)
According to Morgan' s theory, tendon stiffness is constant at any force levels and muscle stiffness is correlated linearly to given force. The purpose of this study was to develop a new method to measure the stiffnesses of muscle and tendon in human calf muscles. Ten young male subjects participated in the study. Percutaneous tetanic electrical stimulation was given to right calf muscles in different levels of stimulation intensity. During the tetanus a short fast stretch was given. The changes of muscle force during the stretch were measured by a KIN-COM dynamometer. The ratio between the change of force and the displacement by stretch gives a measure of stiffness of the muscle-tendon complex. The result showed that the inverted force level and the inverted stiffness of the complex were significantly correlated. By use of this measurement at several levels of force, both muscle and tendon stiffness could be calculated separately. Test-retest reliability was demonstrated.