VASCULAR REACTIVITY IN CATS DURING INDUCED CHANGES IN THE ACID-BASE BALANCE OF THE BLOOD.
Abstract
The aim of the present investigation was to study the mechanisms by which the cardiovascular effect of vasoconstrictor stimuli are modified during respiratory acidosis and primarily the behaviour of some vascular beds in the peripheral circulation. The reactivity (responsiveness) of peripheral vessels during acid-base shifts was estimated in the following vascular beds perfused in situ using the cats own blood and with a constant flow perfusing technique: (a) muscle vessels (skinned hind leg), (b) skin and muscle vessels (unskinned hind leg) and (c) renal vessels (kidney). Changes in reactivity during acid-base shifts were determined either as the change in the pressor response of a vasoconstrictor stimulus or as the ratio between doses elicitating the same pressor response both during the control period and during a period of changed acid-base balance. Respiratory acidosis decreased the systemic blood pressure responses to injected noradrenaline and the decrease was correlated with the degree of acidosis. To induce the same pressor response during ventilation with 20% CO2 in O2 as during a control period the dose of noradrenaline had to be increased 37 times. The decreased effect of noradrenaline on the cardiovascular system could partly be explained by a decreased reactivity of the perfused vascular beds. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1963
- Accession Number
- AD0635659
Entities
People
- Stellan Bygdeman