Phencyclidine, Lysergic Acid Diethylamide, and Mescaline: Cerebral Artery Spasms and Hallucinogenic Activity
Science – May 29, 1981
Source: OpenAlex
Summary
PCP, LSD, and mescaline induced significant contraction in isolated cerebral arteries, with LSD showing the highest potency. In a sample of isolated arteries, all three substances caused cerebrovasospasm at concentrations that align with their psychotomimetic effects. Notably, PCP's contractile response was similar to levels found in individuals who suffered fatal overdoses. Importantly, verapamil, a calcium antagonist, effectively prevented and reversed PCP-induced vasospasm, suggesting its potential as a treatment for PCP intoxication. This highlights distinct receptors for PCP in cerebral blood vessels.
Abstract
Phencyclidine (PCP), lysergic acid diethylamide (LSD), and mescaline produced potent contractile responses on isolated basilar and middle cerebral arteries, where, in terms of potency, LSD > mescaline > PCP. All three drugs produced cerebrovasospasm in a concentration range which parallels that needed for their psychotomimetic and intoxicating actions. Specific receptors for PCP, which subserve contraction and differ from those for LSD and mescaline, are found in cerebral arteries. Concentrations of PCP that produced near-maximum contractile responses on cerebral arteries were similar to those in the blood and brain of human subjects who had died from PCP overdoses. A specific calcium antagonist, verapamil, readily prevented (and reversed) PCP-induced vasospasm. This study provides direct evidence for PCP receptors in cerebral blood vessels, the biologic action of which can be reversed by a calcium antagonist; the clinical use of the latter could prove invaluable in treating PCP-intoxicated victims.