Impaired Collagen Formation in the Scorbutic Channel Catfish

Abstract

A scorbutic condition was induced in channel catfish reared in floating cages fed a commercially available floating catfish ration devoid of ascorbic acid. The major pathological conditions observed were altered pigmentation, lordosis, scoliosis, and ultimately, a broken back. Serum alkaline phosphatase activity, intravertebral collagen, and the amino acid composition of the isolated collagen were determined in the scorbutic fish and compared to values obtained from ascorbic acid-supplemented channel catfish. The serum alkaline phosphatase activity was 65% lower in the scorbutic fish than the supplemented fish. The collagen content of the vertebrae from the scorbutic fish was about 42% less on a dry weight basis than the supplemented fish. The collagen from the scorbutic fish was also found to contain significantly less hydroxyproline than the collagen from the supplemented group. These data indicated that the major ascorbic acid deficiency symptoms observed, i.e., lordosis, scoliosis, and the broken back were due to impaired collagen biosynthesis due to the absence of dietary ascorbic acid.