Chronic effects of hyperproteinemia on blood volume and lymph protein concentration

The long-term effects of hyperproteinemia on blood volume and lymph protein concentration were studied in six conscious dogs over a 17-day period. Plasma protein concentration (PPC) was increased by daily intravenous infusion of approximately 300 ml of previously collected autologous plasma. By day 17 PPC had increased 2.4 g/dl, and plasma colloid osmotic pressure had increased 51%; however, blood volume was not changed. Also, at this time sulfate space, an index of extracellular fluid volume, had increased 12%, prenodal lymph protein concentration had increased from 1.6 to 5.1 g/dl, mean arterial pressure was unchanged, circulating protein mass was increased, and plasma sodium concentration was decreased slightly. In conclusion, the increase in lymph protein concentration during hyperproteinemia may indicate that interstitial fluid protein concentration also increased. This, in turn, would help to prevent any increase in the transcapillary colloid osmotic pressure gradient and thus attenuate any changes in blood volume.