PHARMACOLOGICAL EVIDENCE FOR MULTIPLE SITES OF ACTION OF PRESSURE IN MICE

  • 1 January 1981
    • journal article
    • research article
    • Vol. 8  (1) , 1-11
Abstract
The ability of 8 diverse pharmacological agents to ameliorate the high pressure nervous syndrome (HPNS) in mice was studied. Coarse tremors, complete spasms, clonic convulsions, tonic convulsions and death were the end points evaluated. The 3 anesthetics examined (N2, urethane and phenobarbital) gave good protection against all end points but especially against tonic convulsions. Marked increases (> 90 atm) were recorded in the lethal pressure in spite of a fixed linear compression. Some detailed differences among the anesthetics were noted. Of the anticonvulsants, phenytoin protected against tonic convulsions but actually exacerbated some other end points. Diazepam and trimethadione gave some protection against all phases except the tremors. Tetrahydrocannabinol and chlorpromazine had little effect. The pharmacological profiles of these end points are all different. They may represent the effects of pressure at separate and distinct sites in the CNS. The HPNS is not a single syndrome. Applications to human divers is discussed.