476 H. H. TALLAN 
TABLE TA” 
AMINO ACIDS IN BRAIN 
Concentrations in wmoles/g. Reference numbers indicated between ( ). 








Species Glycine Alanine Serine Saat Threonine Taurine Rn 
| | | 
Man Te te (127) ve) 0.53 (127) 1.45 (127) 0.08, 
(frontal I.I—2.5 
lobe) | | |(127, 162) 
Monkey 10.45, 0.58 
| | |(127, 162) 
Cattle | | | 0.054 (162) 
Cat 0:01 ies 0.94 (160) |0.72 (160) | 0.22 (160) 1.9 (160) 0.12 (162) 
(101, 160) 
Guinea-pig (2.3 (101) | | | 0.8 (12) (0.14 (162) 
Rabbit [i222 1.25 5.8 (154) | 10.58 (154) Moly 7097/ | 
|(101, 154) | (154, 164) | (12, 154) | 
Rat |O.9I—2.7 0.25—-0.96, |0.66-1.8, |0.21,0.94 |0.30—1.6 2.3—5-4, \0.18 (162) 
(7; 28, 57, |2-6 (7,285) \2.81(7,:28,,_ (G18; 135) (28557, 94, toay (7/5 MDs 
|73, 94, IOI, |51, 57, 73, |57, 73, 94 121, 126, 13, 51, 57, 
126,136) |94, 126, 126, 136) '136, 149, 73, 81, 94, 
/136) | |150, 178) |126, 136) 
Pigeon (a Sion) 
Duck | | | | | (0.009 (162) 
Hen 0.68, 1.8 0.48, I.o L077; 0.07, 0.23 |0.35-0.66 0.97-3.2 (0.027 (162) 
(126, 136) |(126, 136) |(126, 136) |(16,135)  |(16, 126, 136) |(16, 126, 136) | 
Fish 0.8 (126) |0.25 (126) |0.28 (126) | (0.66 (126) 3-4 (126) 
Tortoise 0.15 (126) |o.12 (126) |o.12 (126) 0.04 (126) 0.31 (126) 
Frog 1.6 (126) 0.24 (126) |o.20 (126) 0.15 (126) 0.048 (126) | 
Horseshoe | 0.67 (162) 
crab | | 




group, serine plays a role in lipid as well as in protein chemistry. Phosphatidyl- 
serine itself is best discussed with the other “cephalins”; the presence of serine in 
incompletely characterized phospholipids not identical with phosphatidylserine has 
also been reported**; 1”7, Free phosphoserine was provisionally identified in brain by 
RoBERTS!”° and its presence, at concentrations of about one-fifth that of serine, was 
established by PORCELLATI AND THOMPSON?*; 186, Since phosphoethanolamine and 
phosphocholine are both found in brain, the existence of phosphoserine was to be 
expected; glycerophosphoserine, on the other hand, has not yet been detected. The 
quantity of phosphoserine in nerve increases after section!*®, as does the quantity 
of serine, threonine, and of the other amino acids®®, The distribution of serine and 
threonine in parts of the human brain has been studied?2’. 
Taurine (Tables IIA and B). Extremely large variations in the taurine concentra- 
tion of the nervous tissue of various species have been reported. In invertebrate 
nerve, the very high concentrations have been regarded as necessary to help balance 
the high cation concentration: 1°; it should be noted that in squid giant nerve 
axoplasm the related 2-hydroxyethanesulfonic acid (isethionic acid) is also present 
in large amounts for presumably the same purpose*® %6, Large amounts of taurine 
occur in the retina of many species!; an estimate of the concentration in cow 
References p. 482/485 
