Because of a possible relationship between schizophrenia and celiac disease, a condition in some individuals who are sensitive to wheat gluten proteins in the diet, there has been interest in observations that peptides derived from wheat gluten proteins exhibit opioid-like activity in in vitro tests. To determine the origin of the peptides exhibiting opioid activity, wheat proteins were fractionated by size (gel filtration), by charge differences (ion exchange chromatography) and by differences in hydrophobicity (reversed-phase HPLC). These fractions were hydrolyzed by pepsin or pepsin and trypsin and the resulting peptides separated by gel filtration chromatography. The separated peptides were tested for opioid-like activity by competitive binding to opioid receptor sites in rat brain tissue in the presence of tritium-labeled dihydromorphine. The peptides showed considerable differences in activity; while some peptides exhibited no activity, 0.5 mg of the most active peptides were equivalent to 1 nM of morphine in the binding assay. The most active peptides were derived from the gliadin fraction of the gluten complex.

Animals↗

PubMedDate not supplied

Lithium metabolism and intracellular electrolytes.

Lithium chloride was administered orally to swine and two different types of sheep, HK and LK. There was a pre-lithium 16-fold variation in intracellular sodium (LK greater than HK greater than swine) and a 6.5-fold variation in the intracellular potassium (swine greater than HK greater than LK). Collected plasma and erythrocytes were analyzed for lithium, sodium and potassium. The ratio of erythrocyte lithium/plasma lithium was directly related to the pre-lithium erythrocyte sodium concentration and inversely related to the pre-lithium erythrocyte potassium concentration.

Animals↗