INFLUENCE OF PROTEIN CONTENT UPON THE ELECTROLYTE COMPOSITION OF LYMPH AND PLASMA

Abstract

The concentration of Na^+ and Cl' is higher in renal
hilar lymph (HL) than in arterial (P) or renal
venous plasma or thoracic duct lymph (TDL). The
purpose of the present study was to test the theory
that this is the consequence of differences in protein
content of lymph and plasma rather than a reflection
of renal function. Samples of P, HL and TDL
were obtained from dogs and analysed for Na^+, Cl',
K^+ and Ca^++. The samples were then centrifuged
through an ultrafiltration membrane to remove the
protein and reanalysed for electrolyte content.
Ca^++ concentrations were reduced by 30-40% in
the (protein-free) filtrate. This was attributed to
protein binding. Na^+ and Cl' concentrations were
raised minimally (2.0 mEq/L and 5.0 mEq/L
respectively) in protein-free filtrate of plasma, but
not in protein-free filtrate of lymph. It was concluded
that the relative protein concentration in
lymph and plasma are not an important influence
on Na^+ and Cl' concentrations.