When blood plasma proteins are depleted by bleeding, with return of washed red cells (plasmapheresis) it is possible to bring the dog to a steady state of low plasma protein and uniform plasma protein production on a basal diet. Such dogs are excellent test subjects by which the potency of various diet factors for plasma protein regeneration can be measured.
To regenerate plasma proteins in any significant amount the depleted dog requires food protein. Some proteins are very potent for new plasma protein production and others are utilized poorly.
Beef serum is very potent and its proteins (2.6 gm.) will produce 1 gm. of new plasma protein in the depleted dog—a potency ratio of 2.6.
Kidney protein stands at the bottom of our list and the dog needs 21 gm. of kidney protein to regenerate 1 gm. of plasma protein—a potency ratio of 21.0.
Some grain proteins approximate the potency of beef serum and may show potency ratios of 2.7 to 4.6. Some of these grain proteins appear to favor the production of globulin more than albumin in the plasma.
Skeletal muscle, gizzard (smooth muscle), lactalbumin and egg white fall into a favorable group with a potency ratio of 5.3 to 6.0.
Whole liver, liver fractions, casein, and beef heart are a little less potent and present potency ratios of 6.5 to 8.0. Many of these food substances favor the production of albumin more than globulin.
Pancreas and salmon muscle show less favorable potency ratios of 19.0 and 15.0 respectively.
Fasting periods indicate that these depleted dogs can produce little if any new plasma protein.
Iron feeding in some unexplained manner will influence body metabolism so that an excess of plasma protein will be produced.
These observations have a bearing on clinical conditions associated with hypoproteinemia and give suggestions for diet aid or control in some of these abnormal states. The make-up of the diet is obviously of great interest and it is possible that protein combinations may be more potent than a single protein or that food potency ratios may differ in health and disease.