contractile properties of rat skeletal muscles following storage at 4 degrees c the purpose of this study was to assess the potential of preservation solutions for protecting skeletal muscle function during storage at 4 degrees c the soleus and the cutaneus trunci ct from the rat were stored for 2 8 or 16 h at 4 degrees c in university of wisconsin solution uw htkbretschneider solution htk or krebshenseleit solution kh after storage muscles were stimulated electrically to analyse the isometric contractile properties such as the maximum tetanic tension p0 histological analysis was also performed in separate experiments the effect of the diffusion distance on muscle preservation was studied by bisecting the soleus after 8 h of storage in uw or htk the contractile properties of the ct were similar to those of the control whereas those of the soleus were reduced p0 values of 16 and 69 of control in uw and htk respectively at 16 h the contractile properties of the ct po 28 were again better preserved than those of the soleus p0 9 muscle function deteriorated most after storage in kh p0 at 16 h soleus 3 ct 17 the bisected soleus was equally well preserved as the ct po of bisected soleus at 8 h in uw and htk 86 the functional data corresponded well with the histological data which showed increasing muscle fibre derangement with increasing storage time for both muscles and all solutions the threshold stimulus current increased with increasing storage time control 01 ma 16 h 12 ma and was strongly correlated with the deterioration in contractile properties it is concluded that at 4 degrees c muscle is preserved better in uw and htk intracellularlike solutions than in kh extracellularlike solution the soleus and ct were best protected in htk the diffusion distance is a critical factor for successful preservation of muscle function at 4 degrees c the reduced function after 16 h of storage at 4 degrees c was caused by hypercontraction and necrosis of about 25 of the muscle fibres and by deterioration of the electrical component of excitationcontraction coupling of the remaining fibres