PLASMA SUBSTITUTES 



65 



of molecular weight. According to Squire, average 

 molecular weights of various dextrans may range 

 from 11,000 to 1,700,000 as determined by the ultra- 

 centrifuge. According to Marshall and associates 

 (6g) the Swedish dextran Macrodex used in their 

 studies as 6% dextran in 0.9 St sodium chloride was 

 slightly greater than three times water viscosity. 

 Plasma was one and one-half times water viscosity. 

 In our studies (31) a comparison was made between 

 the viscosity of 6 % dextran in saline (Abbott Labora- 

 tories) and that of dog blood at various hematocrits. 

 The blood-to-dextran viscosity ratio was i . 1 2 when 

 the hematocrit was 36. When the hematocrit was 40.5 

 the ratio was 1.23, and when the hematocrit was 

 50 it was 1.3 1. 



Roome and associates (90) studied properties of 

 various polyvinyl alcohols using grade Rh 623. They 

 found that this substance was sterilizable by auto- 

 cla\ing, that it did not gel at ordinary temperatures. 

 Its viscosity was five times that of water. Solutions of 

 2.8 and 3.8% gave osmotic pressures of 30 and 40 

 mm Hg, respectively. 



Taylor & Waters (102) studied the properties of 

 7% isinglass or fish swim bladder gelatin in 0.9% 

 saline. Its osmotic pressure was higher than that of 

 plasma (38 mm Hg). Its viscosity was twice that of 

 plasma and three times that of water, but less than 

 that of whole blood. The solution was readily sterilized 

 at 100° C for 5 min. 



F.\TE OF PLASM.\ SUBSTITUTES ON 

 INTRAVENOUS INJECTION 



In considering the use of plasma substitutes it is 

 desirable to know how long they remain in the plasma, 

 to what extent they are excreted in the urine, whether 

 or not they are metabolized, whether or not they 

 are stored for extended periods in the reticuloendo- 

 thelial system or in other organs, and whether or 

 not they produce damage to the organs in which 

 they are stored either temporarily or permanently. 

 In addition it is desirable to know whether there 

 are other pathways than the urine for elimination, 

 e.g., into the bile and by secretion into the gastro- 

 intestinal tract. 



Dick and associates (26) treated four children with 

 nephrosis by means of intra\'enous acacia. In one 

 patient who had received a total of 129 g of acacia, 

 acacia was found at necropsy in the liver, spleen, 

 kidney, lungs, lymph nodes, and bone marrow. 

 Analysis of the liver revealed 3.9 "0 acacia. The 



plasma level was 2.1 To at this time; the pericardial 

 fluid 0.6 '"i , the peritoneal fluid i . i 7c, and bile 2 %. 

 Bollman (15) stated that he gave dogs acacia intra- 

 \enously at approximately weekly intervals for 6 

 months. Ten years later liver biopsy in these animals 

 showed acacia still to be present in the liver, although 

 liver function tests were normal. Andersch & Gibson 

 (4) gave rabbits intracardiac injections of 30% 

 acacia at 2- to 4-day intervals. At necropsy 35% to 

 6o'"c of the injected amount was found in the liver, 

 with lesser amounts in the spleen, kidney, and skeletal 

 muscles. The liver cells were enlarged and vacuolated. 

 The KupfTer cells appeared to be normal. In a patient 

 who was treated for nephrosis with acacia, 43 % of 

 the injected acacia was found to be in the liver. 

 Injections of acacia had been given up to the time of 

 death. Dogs given acacia were found to have hepatic 

 retention, output of acacia into the bile, and decreased 

 excretion of bilirubin and bile acids. 



Polyvinyl Alcohol 



Roome and associates (90) gave five dogs 14. i to 

 70 g of polyvinyl alcohol, grade Rh 623. Autopsy 

 showed no evidence of storage or visceral damage in 

 these animals. Hueper (54), using a diiTerent fraction 

 of polyvinyl alcohol, gave to three rabbits daily 

 injections of 5% polyvinyl alcohol in 0.85% sodium 

 chloride. One rabbit received 10 injections of 10 ml 

 each, one receised 15 injections, one received 25 

 injections, the last 5 being 20 ml. At necropsy the 

 lungs showed peri\ascular and peribronchial eosino- 

 phils and lymphocytes with occlusion of smaller 

 blood \essels by leucocytic thrombi. The spleen 

 showed foam cells, and there were foam cells in the 

 bone marrow of the rabbit receiving the largest 

 dose. Spermatogenesis was arrested, and in the blood 

 vessels of the brain a blue material filling or coating 

 the inner walls of the blood vessels was seen. Scattered 

 pulmonary obliterative arteriosclerosis was observed. 

 Tubular degeneration was seen in the kidneys, perhaps 

 due to coating of the walls of the renal blood vessels 

 and interfering with the exchange of nutritive sub- 

 stances and metabolites. Hueper concluded that 

 polyvinyl alcohol was removed and stored principally 

 by the reticuloendothelial cells of the spleen, adrenals, 

 and li\er; and, to a lesser degree, by those of the 

 lymph nodes. The only parenchymal cells containing 

 poly\inyl alcohol were the renal tubules, adrenal 

 cortex, and some brain ganglion cells. 



