EFFECTS OF INDENOLOL (YB-2), A NEW BETA-ADRENERGIC BLOCKING-AGENT, AND ITS DEXTRO ISOMER ON CENTRAL NERVOUS-SYSTEM OF MICE AND RABBITS

  • 1 January 1978
    • journal article
    • research article
    • Vol. 234  (1) , 74-87
Abstract
Central depressant actions of a new .beta.-adrenergic blocking agent, indenolol (YB-2), and its dextro isomer were studied in mice and rabbits. d-Indenolol was less active than dl-indenolol in lowering of methamphetamine group toxicity and calming of fighting behavior, though muscle relaxant, hypolocomotive and anticonvulsant effects of d-indenolol were virtually equal to those of the racemate. dl-Propranolol showed a similar profile of central depressant actions to dl-indenolol, whereas dl-practolol revealed no significant central effects in mice. The dose-response relationship between .beta.-blocking and central effects in the same animal species suggested that both taming and anti-methamphetamine group toxicity effects of dl-indenolol s.c. do not directly relate to either the peripheral .beta.-blocking or the membrane stabilizing activity. I.v. and intracerebroventricular [i.c.v.] administration of dl-indenolol resulted in suppression of pressor responses to the electrical stimulation of the brain stem of unanesthetized rabbits. Neither d-indenolol nor dl-practolol was effective against the pressor responses, suggesting that these 2 compounds acted on the CNS in a manner different from dl-indenolol even when i.c.v. administered. A possible central .beta.-adrenergic blocking effect of dl-indenolol was discussed in the light of mechanisms of an antihypertensive action of this compound.