Abstract
Effects of infusing pentafraction (Pen), a synthetic hydroxyethyl starch plasma volume expander, on lung and soft tissue lymph flux were compared in nonanesthetized sheep that were protein depleted by batch plasmapheresis. Pen (5%) was infused to raise pulmonary arterial wedge pressure by 5 mmHg for 2 h (1.8 ± 0.3 l). Pen raised plasma osmotic pressure from plasmapheresis baseline (10.7 ± 2.2 mmHg; preplasmapheresis baseline, 19.6 ± 0.6 mmHg) to 18.6 ± 2.4 mmHg. After Pen, lung lymph flows peaked at 3.9 ± 2.0 times a preplasmapheresis baseline value of 1.0 (plasmapheresis baseline, 2.7 ± 0.7), but soft tissue lymph flows rose insignificantly. Plasma Pen concentrations were 2.3 ± 1.0% postinfusion and 1.6 ± 0.3% at 12 h. Pen mean molecular masses at these times, measured by high-performance liquid chromatography, were 160 ± 44 and 129 ± 23 kDa, respectively. In lung lymph, Pen concentrations were 0.8 ± 0.6% postinfusion and 0.7 ± 0.2% at 12 h, with mean molecular masses of 125 ± 44 and 112 ± 18 kDa, respectively. In soft tissue lymph Pen was nearly undetectable postinfusion, but at 12 h concentrations averaged 0.3 ± 0.2% with a mean molecular mass of 80 ± 10 kDa. The osmotic effectiveness of Pen may be related to its molecular mass, which was large enough to restrict filtration so that the plasma-to-lung lymph osmotic pressure gradient widened. Pen remained effective in the circulation for at least 24 h.
Original language | English (US) |
---|---|
Pages (from-to) | H1536-H1543 |
Journal | American Journal of Physiology - Heart and Circulatory Physiology |
Volume | 265 |
Issue number | 5 34-5 |
DOIs | |
State | Published - 1993 |
Externally published | Yes |
Keywords
- lymph flow
- microvascular filtration
- plasma osmotic pressure
- plasma protein depletion
- plasma volume expanders
ASJC Scopus subject areas
- Physiology
- Cardiology and Cardiovascular Medicine
- Physiology (medical)