UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Vascular smooth muscle and red cell sodium and potassium in haemorrhagic shock measured by lithium substitution analysis Day, Brian


A new method of measuring intracellular Na and K using Li substitution was applied to a study of vascular smooth muscle and red cell Na changes in haemorrhagic shock. A rat haemorrhagic shock model was used. Controlled haemorrhage was allowed with a syringe reservoir and the arterial blood pressure was maintained at 30 mm Hg. In a pilot study, using 20 rats, the plasma Na and plasma K were monitored. A fall in plasma Na and a rise in plasma K were observed. Both returned towards normal following retransfusion and recovery for one hour. In vascular smooth muscle, significant changes in both cell Na and K occurred following a 2 hour period of haemorrhagic shock. The vascular smooth muscle cell Na in control animals was 27.0±1.5 mEq/kg dry weight and 42.7±1.4 mEq/kg dry weight in the shocked animals (P<0.001). The cell K was 127.8±6.0 in the control animals and 74.7±4.2 in the shocked animals. In red cell studies, significant increases in red cell Na were found. The red cell Na in controls was 7.09±0.29 mEq/litre cells, whilst in the shocked animals the red cell Na was 8.26±0.33 mEq/litre cells (P<0.025). This was associated with a small but not statistically significant fall in red cell K. In both sets of experiments, the plasma Na and K were monitored and similar changes to those of the pilot study were found. Following retransfusion and recovery for 1 hour in the vascular tissue study and 2 hours in the red cell study, no significant recovery of cellular Na or K occurred. The results of these studies are consistent with a significant impairment of cell membrane function in haemorrhagic shock. The importance of both normal vascular responses and red cell function following severe haemorrhage is obvious. The fact that both may be impaired may have important implications in relation to the treatment and prognosis of haemorrhagic shock.

Item Media

Item Citations and Data


For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.