EFFECT OF DEFICIENCY IN ANIMALS 



quantities ; the vitauiia B^ requirements for metabolising fat appear 

 to be intermediate between those required for carbohydrates and 

 alcohol. "^ 



Finally, E. Sarfy ^ reported that in vitamin Bi-deficient pigeons 

 the adrenals show a small increase in adrenaline content, whilst that 

 of the blood undergoes a decrease, followed later by a reduction in the 

 amount in the adrenals and an increase in the amount in the blood. 

 Reversal of these changes occurs on administering aneurine. 



Effect in Chicks 



Chicks respond to aneurine deficiency in a very similar way to 

 pigeons and exhibit opisthotonus, owing to functional impairment of 

 the inhibitory fibre from the upper to the lower brain. In chronic 

 deficiency, leg weakness and nerve degeneration occur, the axis 

 cylinder degenerating and then the myelin sheath ; finally the cell 

 undergoes chromatolysis.^ Myelin degeneration in the peripheral 

 nerves and spinal cord is not observed in acute aneurine deficiency in 

 chicks.* Heart failure is shown by some birds, with necrosis of the 

 myocardial fibres. Actually, changes in the electrocardiogram occur 

 two days before the other s3rmptoms of vitamin B^ deficiency make 

 their appearance,^^ the changes becoming more pronounced as the 

 deficiency progresses. On administration of aneurine, the s3niiptoms 

 rapidly improve, but the electrocardiogram only slowly retruns to 

 normal. 



The blood-sugar of chicks is reduced during the first ten to fourteen 

 days on a vitamin Bi-deficient diet ; ^^ it then increases and when 

 convulsions occur it may have twice the normal, value. Injection of 

 aneurine restores the blood-sugar level to normal. Changes in the 

 nerves due to vitamin B^ deficiency have been demonstrated in tissue 

 culture experiments, 12 the length and density of nerve fibres in em- 

 bryos grown in plasma from vitamin Bi-deficient chicks and the density 

 of the spindle cells being less than in embryos grown in normal plasma ; 

 the density of the macrophages was not significantly affected. Addi- 

 tion of aneurine to the deficient plasma increased the spindle cell 

 density, but did not affect the fibre length or density. In blood clots 

 washed with sulphite to destroy aneurine, normal axon growth 

 occurred, however, and the abnormal growth in vitamin Bi-deficient 

 plasma may be due to the greater fluidity of deficient plasma. 



Effect in Rats 



Rats, when fed a diet inadequate in vitamin B^, show a steady 

 decline in weight, once the tissues have been depleted of their stores 

 of the vitamin ; this change in weight, as already mentioned (see 



47 



