Author/Editor		Fazarinc, G; Bavdek, S; Lorger, J
Title		Postnatalne histokemične in morfometrične spremembe v skeletnem mišičju domačega prašiča
Translated title		Postnatal histochemical and morphometric changes in the muscles of the domestic pig
Type		članek
Source		Zb Vet Fak Univ Ljublj
Vol. and No.		Letnik 28, št. 2
Publication year		1991
Volume		str. 151-65
Language		slo
Abstract		In two mustles (m. trapezius thoracis, m. longissimus dorsi) of the domestic pig muscle fiber types were determined on the basis of myosin ATP-ase and SDH-ase activity. The proportion and size of the myofiber types were defined in three different age groups (newbornes 3 week old pigs, 6 months old pigs). On the basis of myosin ATP-ase activity, t.he slow contractile type I myofibres and fast contractile type II myofibres were distinguished. Type II myofibers were devided into three subtypes: IIB, IIA and IIC. On the basis of SDH-ase activity of oxidative and metabolic mixed fibers were distinguished, in which the activity of enzyme is expressed (SDH+-), and glycolitic fibers where SDH-ase activity (SDH-) is not expressed. In the trapezius muscle of the newbornes a larger proportion of type I (21.9 per cent ) and IIC (10.5 per cent ) is present than in the longissimus muscle (4.5 per cent , 5.2 per cent ). On the basis of SDH-ase activity no distinction between the fibers in newbornes is obvious. During the first three weeks the proportion of type I myofibers is increased in both muscles. The transformation is taking course through the subtypes IIA and IIC. In the period from three weeks to six months the proportion of slow contracting myofibers (type I SDH +) is increasing in the trapezius muscle. In the longissimus muscle the number of fast contracting glycolitic myofibers (type IIB SDH-) is increasing during the same period. In some IIB SDH- myofibers of the longissimus muscle hydropic degenerative changes were observed as conse quence of the intensive anaerobic glycolysis in this type of myofibers.
Descriptors		MUSCLES SWINE MUSCLES AGE FACTORS HYDROGEN-ION CONCENTRATION MYOSIN ATPASE MYOSIN SUCCINATE DEHYDROGENASE