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COMPONENTS OF INJURY (HAEMORRHAGE AND TISSUE ISCHAEMIA) AFFECTING CARDIOVASCULAR REFLEXES IN MAN AND RAT
Author(s) -
Little R. A.,
Randall P. E.,
Stoner H. B.,
Marshall H. W.,
Redfern W. S.
Publication year - 1984
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0144-8757
DOI - 10.1113/expphysiol.1984.sp002866
Subject(s) - medicine , bradycardia , ischemia , blood pressure , reflex , anesthesia , cardiology , valsalva maneuver , blood volume , heart rate
The effects of two components of tissue injury, namely fluid loss from the circulation and tissue ischaemia, on cardiovascular reflex activity have been studied. Moderate blood loss ( 10–20% blood volume) in the unanaesthetized rat increased the slope of the regression line relating heart period to mean arterial blood pressure and usually displaced it to the left (i.e. towards a relative bradycardia). A blood donation of 500 ml (approximately 10% blood volume) increased the Valsalva ratio in conscious man without a change in resting pulse rate. However, a 15 min period of unilateral limb ischaemia in man reduced the Valsalva ratio. The pattern of change in the pulse rat response to the Valsalva manoeuvre produced by limb ischaemia closely resembles that found previously after limb injury in man. There was no evidence that the endogenous opioids were involved in the interaction between limb ischaemia and cardiovascular reflex activity in man.