Post-mortem changes in gene expression of the muscle tissue of rainbow trout, Oncorhynchus mykiss.

A subtracted cDNA library was used to identify specific genes that increase in post-mortem muscle of rainbow trout (Oncorhynchus mykiss) during on-ice storage. Of the 200 cDNAs analyzed, 82 had significant homologies to previously identified genes from salmonids and other species such as homologues of troponin I, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and so on, whereas 40 had no significant homologies and were designated as unknown. Comparison of gene expression profiles by dot blot hybridization confirmed an increase or induction of mRNA in the muscle after 3 h of on-ice storage compared to that at 0 h after death.

Green tea polyphenols inhibit metalloproteinase activities in the skin, muscle, and blood of rainbow trout.

We have investigated the inhibitory effects of polyphenols from natural products, such as green tea, bilberry, grape, ginkgo, and apple, on rainbow trout gelatinase activities. Gelatinases from the skin, muscle, and blood of rainbow trout contained serine proteinase, metalloproteinase, and other proteinase activities as measured by gelatin zymography. The polyphenols of green tea caused the strong inhibition of some gelatinase activities when compared with those of the other products.