Prediction of brain and serum free amino acid profiles in rats fed graded levels of protein.

Daily weight gains and food intakes were measured in male, 120-g rats fed graded levels of dietary casein. After 14 d, serum and brain amino acid concentrations were measured. All physiological responses were tested for a functional relationship to dietary casein concentration.

Isolation, primary structure, and synthesis of alpha-endorphin and gamma-endorphin, two peptides of hypothalamic-hypophysial origin with morphinomimetic activity.

The isolation and primary structure of two peptides with morphinomimetic activity, obtained from an extract of porcine hypothalamus-neurohypophysis, are described. The amino acid sequence of the two peptides, named alpha-endorphin and gamma-endophin, was determined by mass spectrometry and danxyl-Edman methods to be H-Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr-OH and H-Tyr-Gly-Gly-Phe-Met-Thr-Ser-Glu-Lys-Ser-Gln-Thr-Pro-Leu-Val-Thr-Leu-OH, respectively. These correspond to the amino acid sequences present between residues 61 and 76 and residues 61 and 77 of the various beta-lipotropins.