Free amino acids in the hemolymph of the cockroach, Blaberus discoidalis

The concentrations of free amino acids in the hemolymph of adult males of the cockroach Blaberus discoidalis were determined by automated amino acid analysis. Eighteen of the twenty standard amino acids as well as two nonstandard amino acids (hydroxyproline and ornithine) were found. Aspartic acid and cysteine were not present. Proline levels were up to 100-fold higher than those of any other amino acid. Total amino acid concentration was comparable to those reported for most other cockroaches. The reported amino acid profile formed the basis for an organ culture medium which sustained metabolic viability of isolated B. discoidalis neuroendocrine glands and brain-gland complexes for at least 24 hr.