Effect of ischemia on responses of group III and IV afferents to contraction

Marc P Kaufman, K. J. Rybicki, T. G. Waldrop, G. A. Ordway

Research output: Contribution to journalArticle

214 Citations (Scopus)

Abstract

Static contraction of the hindlimb muscles of cats reflexly increases cardiovascular function, an effect that is potentiated by occlusion of the arterial supply to the working muscles. Although group III and IV afferents are known to be stimulated by and to cause the reflex cardiovascular responses to static muscular contraction, little is known about the responses of these afferents to static contraction when the arterial supply to a working muscle is occluded. We therefore recorded the impulse activity of 24 group III afferents and 30 group IV afferents with endings in the triceps surae while we statically contracted this muscle group both when the abdominal aorta was occluded and when it was patent. A χ2 analysis revealed that ischemia increased the responses to static contractions of a significantly higher percentage of group IV afferents than group III afferents (46.7% vs. 12.5%, respectively; P<0.02). In addition, two patterns of responses to ischemic contraction were observed. The first pattern was displayed by afferents (n = 10) that were stimulated by nonischemic contraction but were stimulated more by ischemic contraction. The second pattern was displayed by afferents (n=7) that were not stimulated by nonischemic contraction but were stimulated by ischemic contraction. We conclude that afferents displaying both patterns are likely to contribute to the reflex cardiovascular responses to ischemic contraction.

Original languageEnglish (US)
Pages (from-to)644-650
Number of pages7
JournalJournal of Applied Physiology Respiratory Environmental and Exercise Physiology
Volume57
Issue number3
StatePublished - 1984
Externally publishedYes

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Ischemia
Muscle Contraction
Muscles
Reflex
Abdominal Aorta
Hindlimb
Cats

ASJC Scopus subject areas

  • Physiology
  • Endocrinology

Cite this

Effect of ischemia on responses of group III and IV afferents to contraction. / Kaufman, Marc P; Rybicki, K. J.; Waldrop, T. G.; Ordway, G. A.

In: Journal of Applied Physiology Respiratory Environmental and Exercise Physiology, Vol. 57, No. 3, 1984, p. 644-650.

Research output: Contribution to journalArticle

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