Differences in proteolytic enzyme activities during growth of the pig with different IGF-II genotypes
Van den Maagdenberg, K.; Claeys, E.; Stinckens, A.; Buys, N.; De Smet, S.
Communications in Agricultural and Applied Biological Sciences 69(2): 297-300
2004
ISSN/ISBN: 1379-1176 PMID: 15560245 Document Number: 568854
This study was conducted to evaluate the effect of insulin-like growth factor (IGF-II) genotype on the activities of proteolytic enzymes in the longissimus muscle during the growth of pigs in order to get more insight in the effect of the IGF-II genotype on the growth rate and muscle protein turnover. At approximately 4 and 8 weeks of age, fifteen (6 Qpat and 9 qpat) and ten (7 Qpat and 3 qpat) boars were slaughtered on 5 different days. Muscle samples and organs were taken within 0.5 h after slaughter and weighed. Determination of mu -calpain, m-calpain and calpastatin activities was done. The relative weight of the spleen, liver and longissimus muscle significantly increased with age, whereas that of heart was constant. The relative weight of the triceps brachii decreased, although the effect was insignificant. The activity of m-calpain and calpastatin decreased with age, however the decrease in the latter was insignificant. The ratio between m-calpain and calpastatin activity was constant. mu -calpain activity and the ratio between mu -calpain and calpastatin were similar for the pigs of the 2 age groups. Cathepsin B + L and H activities increased with age, although the effect was insignificant. The slaughter weight of pigs, relative size of the heart and relative weight of the longissimus muscle were similar for the 2 genotypes. Differences in the relative size of the spleen, liver and triceps brachii were observed, but the differences were significantly only for the spleen and triceps brachii. The m-calpain activity was higher for pigs bearing the Q allele. No differences in cathepsin H and B + L were observed. It was concluded that proteolytic enzyme activity in pigs changed with age.