Taurine and other free amino acids in the retina, vitreous, lens, iris-ciliary body, and cornea of the rat eye.

Levels of free amino acids were determined quantitatively in whole ocular tissues of the rat eye with aid of a sensitive amino acid analyzer. The tissues studied were the retina, vitreous, lens, iris-ciliary body, and cornea. The retina and lens contained a more concentrated free amino acid pool than other tissues.

Comparison of different myelin isolation methods by use of nonequilibrium pH gradient gel electrophoresis.

Myelin was isolated from bovine white matter by five published procedures and several modifications of two of them. Comparison of the protein profiles of the preparations by nonequilibrium pH gradient gel electrophoresis, revealed clear differences in myelin protein content and composition between preparations obtained by different methods. In isolation methods where the medium contained salts, some of the myelin proteins were solubilized, the phenomenon being most pronounced in long-period isolations in buffered CsCl solution.

Macromolecular relationships of liver nuclei and amino acid composition of total histones during bovine ontogeny.

The weight of the liver and the macromolecular composition of the liver and its nuclei during bovine ontogeny were compared. The findings suggest that bovine liver growth proceeds in three phases. The macromolecular composition of the liver nuclei was found to remain fairly constant throughout bovine ontogeny.

Resolution and purification of taurine- and GABA-synthesizing decarboxylases from calf brain.

The present work describes a procedure for the co-purification of cysteine sulfinate decarboxylase (CSAD) and glutamate decarboxylase (GAD) from calf brain. A crude enzyme preparation was first made from brain homogenate by acid precipitation and ammonium sulphate fractionation. Subsequent fractionation of the decarboxylase preparation by cation exchange chromatography on CM-Sepharose CL-6B revealed the existence of a specific CSAD enzyme, which has no GAD activity.

Developmental changes in mouse brain polyamine metabolism.

Mouse brain ornithine decarboxylase (ODC) activity is high at the time of birth, whereas S-adenosyl-L-methionine decarboxylase (SAM-DC) activity is low. ODC activity, and putrescine, spermidine and spermine concentrations decline rapidly during postnatal development to the low level characteristic of mature brains, while SAM-DC activity behaves in the opposite manner. The fluctuations in mouse brain polyamine metabolism are in accord with those found in the rat.