Table 49. — Thyroid weights of rats Jed other diets 



Strain and diet 



Rats 



Average 

 age 



Average 



weight 



loss 



Thyroid 



weights 





Average 



Range 



BHE rats 



SPE supplemented with — 



Choline, 0.5% _. .. - 



Number 

 22 

 8 

 9 

 7 

 9 



10 



7 



9 



8 



9 



4 



15 



7 



5 



10 



17 



9 



6 



6 



7 



6 



21 



19 



5 

 5 

 5 



3 

 3 



2 

 2 



4 

 3 



9 

 9 



9 

 9 



Days 

 474 

 463 

 437 

 465 

 412 



430 

 460 

 406 

 436 

 434 

 586 

 553 

 514 

 528 

 503 

 637 

 632 

 483 

 530 

 473 

 550 

 541 

 400 



428 

 425 

 430 



250 

 249 



574 

 396 



686 



577 



727 

 664 



703 

 456 



Grams 

 136 

 131 

 96 

 180 

 218 



138 



155 



142 



129 



183 



77 



98 



109 



80 



66 



172 



118 



166 



155 



178 







129 



73 



66 



35 



5 





 



207 

 133 



109 

 128 



106 



80 



74 

 81 



Mg. 



25. 4 



23. 4 



24. 1 



23. 8 

 21. 



24. 2 

 22 2 

 23! 3 

 23. 2 



25. 4 



14. 2 

 19. 9 



18. 

 17. 9 



15. 4 



19. 



16. 8 



23. 7 

 19. 4 



24. 1 

 10. 3 

 19. 5 



17. 9 



15. 6 

 19. 7 



16. 6 



12. 4 



16. 9 



21. 5 



17. 2 



19. 7 

 22.4 



16. 1 



22. 2 



12. 9 

 21. 7 



Mg. 



12. 9-42. 5 



17. 3-33. 5 



18. 2-32. 8 



18. 0-35. 7 

 9. 7-29. 7 



13. 5-39. 8 



19. 0-29. 8 

 16. 7-29. 4 

 18. 1-28. 6 

 13. 6-36. 



12. 0-15. 7 



13. 7-30. 1 



11. 2-25. 2 

 10. 6-27. 8 



10. 0-23. 3 



8. 7-32. 6 

 7. 3-26. 9 

 7. 6-36. 



9. 2-28. 2 

 18. 1-31. 4 



7. 2-13. 9 

 9. 0-45. 8 

 9. 5-28. 8 



13. 8-17. 6 



13. 1-28. 8 



12. 9-19. 5 



11. 9-12. 7 



14. 5-20. 8 



14. 6, 28. 4 

 17. 1, 17. 4 



13. 0-22. 8 

 21. 3-23. 6 



11. 3-30. 9 



15. 3-34. 1 



5. 8-20. 6 

 9. 9-49. 6 



Bj,, 0.01 mg./lOO gm ... _._ 



Choline, 0.5%+ B^, 0.01 mg./lOO gm 



B 6 , 0.5 mg./lOO gm 



Choline, 0.5%+ B 6 , 0.5 mg./lOO gm ... 



Choline, 0.5% + B 12 , 0.01 mg./lOO gm.+ B 6 , 

 0.5 mg./lOOgm . ...... 



Cholesterol, 0.46%. .. . ..... 



Cholesterol, 1.38% 



Ascorbic acid, 0.2% _ 



Ascorbic acid, 0.2%+ cholesterol, 0.46%. _ 

 SP 16 HVO 



SP8 1ard 



SP 16 lard 



SP 8 butter 



SP 16 butter 



SPa 16 HVO 



SPb 8 HVO 



SPE (fresh egg) 



SPEW 



SPEY 



SPW8HVO 



E100 



Y100 



Littermates fed — 



SPE 



Y100 



Y97+ salt mixture, 3.0%— ._. 



Diet reversal: 



Sacrificed at approximately 250 days: 

 Stock.. ... 



SPE 



Continued on — 



Stock. . . _ ... 



SPE 



Reversed at 250 days: 



Stock changed to SPE . 



SPE changed to stock 



Wistar rats 

 SP 8 HVO 



SPE 



BHE rats of parents fed Wistar stock diet 



SP 8 HVO 



SPE 





fied diet resulted in thyroids similar in size to those 

 from SP 8 HVO rats. Although large thyroids 

 were occasionally found in rats fed the diet con- 

 taining 100 percent egg, the average of 18.0 mg. 

 for the thyroids from 16 rats losing more than 100 

 grams on this diet was considerably less than the 

 24-mg. average observed for comparable SPE rats. 

 On the basis of the limited data available, there 

 was no evidence that supplementation of the diet 

 consisting of 100 percent egg yolk with salt mix- 

 ture had any marked influence on thyroid weight. 

 When feeding of SPE diet was initiated at 250 



days, thyroids tended to be smaller than when 

 this diet was fed throughout life, but more data 

 are needed to establish the significance of this 

 difference. The thyroids from Wistar rats fed 

 SP 8 HVO diet and SPE diet were similar in size 

 to those from comparable BHE rats fed these 

 diets, and no evidence for strain differences was 

 apparent from data on moribund rats. 



Discussion. — Donaldson (50) reported a value 

 of 60.9 mg. for the total thyroid weight in male 

 rats weighing 450 grams. A linear relation be- 

 tween body and thyroid weight was observed. 



61 



