Laterality in Direct and Indirect Inotropic Effects of Sympathetic Stimulation in Isolated Canine Heart

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Author(s)

Abstract

Although sympathetic nerve stimulation is known to increase ventricular contractility, concomitant increases in heart rate (HR) make it difficult to separate its direct inotropic effect from indirect inotropic effect through a force-frequency mechanism. We stimulated the stellate ganglia in 8 isolated canine hearts with functional sympathetic nerves. Right sympathetic stimulation at 10 Hz increased ventricular end-systolic elastance (E<sub>es</sub>) by 95.7 ± 7.5% (p < 0.001) and HR by 32.5 ± 4.2% (p < 0.05). In contrast, left sympathetic stimulation at 10 Hz increased E<sub>es</sub> by 70.7 ± 6.5% (p < 0.001) without significant changes in HR. Preventing the chronotropic response by fixed-rate pacing attenuated the E<sub>es</sub> response to right sympathetic stimulation at 5 Hz (52.0 ± 5.1 vs. 22.8 ± 2.8%, p < 0.001), but not to left sympathetic stimulation at 5 Hz (54.5 ± 3.4 vs. 53.3 ± 2.2%, NS). In the isolated canine heart, the right sympathetic nerve affected E<sub>es</sub> by both the direct inotropic effect and the indirect HR-dependent inotropic effect. In contrast, the left sympathetic nerve regulated E<sub>es</sub> primarily by its direct inotropic effect.<br>

Journal

  • The Japanese Journal of Physiology

    The Japanese Journal of Physiology 51(3), 365-370, 2001-06

    THE PHYSIOLOGICAL SOCIETY OF JAPAN

References:  22

Cited by:  2

Codes

  • NII Article ID (NAID)
    10008293883
  • NII NACSIS-CAT ID (NCID)
    AA00691224
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    0021521X
  • NDL Article ID
    5840317
  • NDL Source Classification
    ZS8(科学技術--医学--解剖学・生理学・生化学)
  • NDL Call No.
    Z53-D40
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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