Free amino acids in the hemolymph and midgut epithelium of the silkworm, Bombyx mori (Linnaeus), infected with cytoplasmic-polyhedrosis virus

Abstract

Free amino acids in the hemolymph and midgut epithelium of the silkworm, Bombyx mori (Linnaeus), infected with the cytoplasmic-polyhedrosis virus were compared with those in the hemolymph and midgut epithelium of the healthy silkworm. Amino-acid analysis was done by ion-exchange chromatography using the amino-acid analyzer. More than 20 amino acids (ornithine, lysine, histidine, arginine, taurine, aspartic acid, threonine, serine, glutamine (and/or asparagine), proline, glutamic acid, glycine, alanine, valine, cystathionine, methionine, isoleucine, leucine, tyrosine, phenylalanine, and β-alanine) were found in the hemolymph and the midgut epithelium from healthy or diseased larvae. In the hemolymph and midgut epithelium of the diseased larva, most of the amino acids decreased. Their amount ranged from one-half to one-tenth of the normal amount, but glycine and lysine contents in the hemolymph of the diseased larvae were more than those in the hemolymph of the healthy ones. Nineteen unidentified ninhydrin-positive substances were detected in these samples, and two of them were found in the hemolymph or midgut epithelium of diseased larvae only.