Il sistema calpaina/calpastatina in 3 muscoli dell'arto pelvico di struzzo African Black. Studio istochimico, immunoistochimico e morfometrico

In the present research a description of the pelvic limb musculature of ostrich (African Black) was given. Muscle tissues were obtained from three muscles namely: Gastrocnemius pars externa, Tibialis .cranialis caput tibiale, Tbialis cranialis caput femorale. Haematoxilin-eosin technique was used to verify the morphologic aspect of the tissues (fibers integrity). The histochemical results revealed the presence of three fibre types only in the gastrocnemus pars extena uscle : slow-twitch oxidative fibres (SO), fast-twitch oxidative glycolytic fibres (FOG) and fast-twitch glycolytic fibres (FG), while in the other muscles FG fibres were absent. The percentage distribution of fibres types showed a higher incidence of SO compared to FOG fibres in Tibialis cranialis caput tibiale and tibialis cranialis caput femorale. In the Gastrocnemius pars externa muscle the FG fibres outnumber the other fibres, followed by SO and FOG fibres.The results of the analysis of variance showed significant muscle x fibre interactions for every morphometric parameter evaluated. The immunohistochemical results showed the localization of calpain and calpastatin in the muscles object of study. These molecules are involved in the degradation of same myofibrillar proteins and therefore they are relevant factor for meat quality. The brief activity period of the calpain/calpastatin system could explain, in the ostrich, a shorter hanging period.