European Journal of Clinical Pharmacology

, Volume 46, Issue 6, pp 527–532

Recovery cycle of the Hoffmann reflex of tobacco smokers and nonsmokers: relationship to plasma nicotine and cotinine levels

  • E. F. Domino
  • C. Kadoya
  • S. Matsuoka
Originals

DOI: 10.1007/BF00196110

Cite this article as:
Domino, E.F., Kadoya, C. & Matsuoka, S. Eur J Clin Pharmacol (1994) 46: 527. doi:10.1007/BF00196110

Abstract

Ten normal adult tobacco smokers and 10 non-smoking volunteers 20–31 years of age were the subjects of this study. The tobacco smokers all had a history of daily tobacco smoking. They were asked to stop smoking for 12 hours prior to testing. The Hoffmann (H) reflex and its recovery cycle were measured on different days before and just after smoking one nonfiltered 0 mg, low (0.27 mg), or high (2.16 mg) nicotine containing cigarette in a randomized order. Blood samples were drawn immediately after the H reflex recordings in the tobacco smokers. The blood samples were centrifuged, the plasma removed, frozen, and later assayed for nicotine and cotinine levels.

Nonsmokers compared to tobacco smokers before smoking only had a tendency for enhanced amplitude of the recovery cycle. After smoking the nicotine containing cigarettes, the tobacco smokers had a depression of the amplitude of the H reflex recovery cycle. The amplitude of the H reflex recovery cycle at 160 ms was reduced. This decreased significantly with increasing plasma nicotine and cotinine concentrations. Individual differences were marked.

The data obtained are consistent with evidence in animals that nicotine and tobacco smoke stimulate Renshaw inhibitory neurons in the spinal cord, either directly or indirectly which leads to a skeletal muscle relaxant effect.

Key words

Hoffmann reflexTobacco smokingrecovery cycleplasma nicotineplasma cotinine

Copyright information

© Springer-Verlag 1994

Authors and Affiliations

  • E. F. Domino
    • 1
  • C. Kadoya
    • 1
    • 2
  • S. Matsuoka
    • 2
  1. 1.Department of PharmacologyUniversity of MichiganAnn ArborUSA
  2. 2.Department of NeurosurgeryUniversity of Occupational and Environmental HealthKitakyushuJapan
  3. 3.Department of PharmacologyUniversity of MichiganAnn ArborUSA