Partial purification and pharmacology of peripheral-type benzodiazepine receptors.

This report describes the results obtained with a new photoaffinity ligand for the "peripheral-type" benzodiazepine binding site (PBS), using a digitonin solubilized preparation from rat heart or adrenals. The specific binding activity of the solubilized adrenal preparation is higher than 50 pmol/mg protein, with binding properties and pharmacological specificity identical to the membrane bound PBS. The apparent molecular weight of the solubilized PBS, determined by gel filtration is 215 KDa.

Photoaffinity labeling of peripheral-type benzodiazepine-binding sites.

The use of a novel photoaffinity label for the peripheral-type benzodiazepine-binding site is described. This compound, PK 14105, has high affinity (4 nM) and selectivity for cardiac benzodiazepine-binding sites. Under ultraviolet light, PK 14105 couples covalently to an 18,000-Da membrane protein which apparently corresponds to the (or a part of the) cardiac benzodiazepine-binding site.

Dihydropyridine and peripheral type benzodiazepine binding sites: subcellular distribution and molecular size determination.

Electrophysiological and pharmacological studies have shown that peripheral-type benzodiazepine receptors modulate voltage-sensitive calcium channels in the heart. We have compared these binding sites with binding sites for [3H]dihydropyridines, which are believed to label such channels. Although no direct or allosteric interaction could be demonstrated between the two sites, their subcellular distribution--sarcolemma and ryanodine-sensitive sarcoplasmic reticulum--was parallel.

Characterization of solubilized "peripheral type" benzodiazepine binding sites from rat adrenals by using [3H]PK 11195, an isoquinoline carboxamide derivative.

"Peripheral type" benzodiazepine binding sites have been solubilized with digitonin. Binding site density for the solubilized material is increased 1.7 times compared to membranes.

[L-Methionine treatment of Parkinson's disease: preliminary results].

Eleven patients with previously untreated Parkinson's disease were treated with L-Methionine for periods from 2 weeks to 6 months. The treatment was well supported and good improvement in clinical signs, particularly akinesia and rigidity, appeared within approximately three weeks, the effect on tremor being less marked. Therapeutic effects were similar to those observed with L-dopa treatment.