Table 73. — PA, 1 serum cholesterol, kidney weight, and kind and extent of kidney damage in rats Jed SP 



8 HVO and SPE diets 



Diet and PA 



Rats 



Average 

 age 



Average 

 PA 2 



Serum cholesterol 2 



Kidney weight 



Rating of kidney damage 



range 



Average 



Range 



Average 



Range 



Hyalin 



Cystic 



Glomer- 

 ular 



SP 8 HVO: 

 PA, none 



Less than 4.0 



4.0 to 7.9 



8.0 and over.. 



SPE: 



PA, none__ 



Less than 4.0 



4.0 to 7.9 



8.0 and over 



Number 



25 



10 



6 



1 



20 



8 



15 



12 



Days 

 426 

 493 

 520 

 544 



405 

 419 

 426 

 434 



Percent 

 



2.7 



6. 8 



17. 6 







2. 6 

 5.7 



11. 7 



Mg./lOO 

 ml. 

 117 

 129 



188 

 270 



225 

 286 

 314 



488 



Mg./lOO 

 ml. 



81-185 

 112-192 



108-278 

 270 



152-326 

 132-434 

 152-437 

 237-743 



Grams 

 1.7 



1. 5 



2. 5 



5. 2 



3 2. 2 

 2. 1 

 4. 8 



6. 1 



Grams 

 1. 2- 3. 4 

 1. 2- 2. 

 1. 8- 4. 5 



5. 2 



1. 5- 4. 7 

 1. 8- 3. 6 

 1. 6-10. 1 

 1. 8-11. 2 



/Score 



0. 3 

 . 3 



1. 5 

 2.0 



1. 2 

 1. 2 



1. 8 



2. 1 



Score 

 

 



0. 5 

 3.0 



. 4 

 



1. 5 



2. 7 



Score 

 

 



0.5 

 2. 



2 



o' 



.9 



1. 2 



1 PA represents prealbumin component or components moving more rapidly than albumin. 



2 PA values represent relative percentage of serum protein components. Cholesterol values represent milligrams 

 per 100 milliliters in serum. 



3 Omitting one rat with kidney weight of 13.2 grams — no PA and cholesterol 202 mg./lOO ml. 



PA was absent from the sera, cholesterol levels 

 were generally low and the kidney small with 

 little evidence of damage. Only 3 of the 25 rats 

 in this group had kidneys exceeding 2.0 grams 

 in weight, and only 5 had serum cholesterol levels 

 exceeding 150 mg./lOO ml. When the PA level 

 in the serum was less than 4 percent of the serum 

 proteins, cholesterol levels and kidney weights were 

 similar to those for rats with no PA in their sera. 

 When the PA level was above 4.0 percent, kidneys 

 were generally enlarged and cholesterol levels 

 exceeded 150 mg./lOO ml. in all but 1 rat. 



On SPE diet a similar trend was observed, 

 although the range of values was wide for each 

 group. In the group of 20 rats with no PA in 

 their serum protein, only 1 had a serum cholesterol 

 level in excess of 300 mg./lOO ml. and 2 of the 

 kidneys exceeded 3.0 grams in weight. Excluded 

 from the data was 1 rat with a very large kidney 

 weighing 13.2 grams. This rat had no PA in the 

 serum and a serum cholesterol of 202 mg./lOO ml. 

 In the group of 12 rats with PA levels 8 percent 

 and over, only 1 had a serum cholesterol value of 

 less than 300 mg./lOO ml.; the others had values 

 exceeding 400 mg./lOO ml. Three of the kidneys 

 weighed less than 3 grams; eight exceeded 6.0 

 grams. In general, high concentrations of PA in 

 serum proteins tended to parallel serum cholesterol 

 levels somewhat more closely than kidney size. 



Rats fed SPM, SPB, and SPPB diets.— In 

 table 74 are summarized limited data from 

 electrophoresis of the sera from rats fed SPM, 

 SPB, and SPPB diets. There were insufficient 

 data to establish the influence of age. With each 

 of these diets the fast-moving component was 

 present in the sera of some of the rats, even among 

 the relatively young animals. The highest level 

 observed was for a rat fed SPM diet, with the 

 fast-moving component representing 20 percent 

 of the serum proteins. The other serum proteins 



were present in amounts that were similar to 

 those found in rats fed SP 8 HVO or stock diets. 



Discussion. — Many factors have been shown 

 to influence the results of electrophoretic studies 

 of blood proteins, and hence to complicate com- 

 parisons of the results of such studies (28, 4-9, 133). 

 Concentration and kind of buffer, optical devices 

 used to resolve the protein concentration gradients, 

 and species, strain, sex, and age of the experi- 

 mental animals may all be determining factors. 

 Many of the investigations have dealt with at- 

 tempts to characterize certain pathological condi- 

 tions by means of the electrophoretic pattern of 

 the blood proteins. There appear to be no 

 reports of investigations comparable to those 

 included in this bulletin dealing with the electro- 

 phoretic pattern of the blood proteins of rats on 

 various dietary regimens throughout their lifespan. 



In 1945, Deutsch and Goodloe (49) investigated 

 the plasma proteins of 20 species of animals and 

 obtained evidence of a small amount of protein 

 migrating more rapidly than albumin in certain 

 species, including the rat. These authors reported 

 poor electrophoretic separation for some of the 

 proteins in the blood plasma of rats. Halliday 

 and Kekwick (83) reported, in the blood of young 

 rats, a component moving ahead of albumin, 

 possibly a second albumin, which varied in con- 

 centration from 8.6 percent at 12 days of age to 

 4.2 percent at 90 days. Total albumin increased 

 from 60 to 70 percent of the total protein during 

 this period. A preliminary report (38) from this 

 laboratory indicated the presence of high levels of 

 rapidly migrating proteins in the blood serum of 

 rats receiving a diet containing 25 percent cooked 

 dried whole egg. 



Although data on rapidly moving components 

 in the sera of rats are limited, considerable atten- 

 tion has been given to their occurrence in the sera 

 of humans, variously designated as PA (prealbu- 



89 



