CHRONIC BIFEMELANE HYDROCHLORIDE ADMINISTRATION ENHANCES MUSCARINIC CHOLINERGIC RECEPTOR-BINDING IN THE SENESCENT RAT-BRAIN

In senescent rats, the binding ability of muscarinic cholinergic receptors (MCR) was markedly decreased in the cerebral cortex, hippocampus, thalamus, and the striatum compared with young adult rats. This decrease was markedly improved by chronic administration of bifemelane hydrochloride (bifemelane). In view of the findings that bifemelane markedly inhibits the decrease in acetylcholine (ACh) associated with cerebral ischemia, and that it improves amnesia induced by scopalamine, it may be inferred that bifemelane between in situ malignant melanoma and other melanin-containing in situ malignancies has been presented. All types of malignant melanoma which originate within the epidermis or epithelium have an in situ phase and show horizontal growth, and small early forms defy classification. The classification of the most common types of malignant melanoma has been revised. Although the level of invasion and tumor thickness are useful prognostic and therapeutic parameters, their determination is crude and subject to several shortcomings.