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.

Isoelectric focusing of myelin membrane proteins.

Human myelin was isolated from the white matter of autopsy brains. Myelin proteins were characterized by isoelectric focusing in ultrathin slab gels in a pH range from 3.5 to 10 after solubilization with urea and Nonidet P 40.

On the metabolism of ornithine in synaptosomal preparations.

The present results show that ornithine is metabolized to glutamate by isolated synaptosomes from mouse cerebral cortex. Under the experimental conditions used the glutamate was channelled further to the tricarboxylic acid cycle, and to a lesser degree to GABA. The possible significance of these metabolic pathways are discussed.

Characterization of cerebral cysteine sulfinic acid decarboxylase. Molecular parameters and inhibition studies.

The molecular properties of cysteine sulfinic acid decarboxylase (EC 4.1.1.

Diurnal levels of polyamines and activities of ornithine and S-adenosyl-L-methionine decarboxylases in mouse brain.

The levels of putrescine and spermine in mouse brain were rather constant at different times of day, as were the activities of ornithine and S-adenosyl-L-methionine decarboxylases. Contrary to an earlier report, the level of spermidine was found to be relatively constant. A possibly significant feature in the present results was the steady decline during the light period and rise during darkness of cerebral spermidine and spermine levels, the differences between maximum and minimum being about 15% for both compounds.

Partial purification of cysteine sulfinic acid decarboxylase from calf brain.

Cysteine sulfinic acid decarboxylase (EC 4.1.1.

[The radioprotective effect of iodine and its preventive action on renal calcification (author's transl)].

The protective effect of iodine against injurious damage caused by ionizing radiation was studied in 26 rats irradiated with cobalt-60 gamma rays as a single dose of 1000 rads (10 joule/kg). Twelve rats were pretreated 13 times every second day before irradiation. After irradiation they were treated daily during 21 days with 2.

Stimulation of L-ornithine and S-adenosyl-L-methionine decarboxylases by beta-(p-chlorophenyl)-gamma-aminobutyric acid in mouse tissues.

Injections of beta-(p--chlorophenyl)-gamma-aminobutyric acid caused a monophasic stimulation of the activity of neural L-ornithine decarboxylase, to reach a maximum of 9-fold compared with the control values 3 h after treatment. Stimulation of hepatic L-ornithine decarboxylase was biphasic, the activity reaching its first peak, 48-fold compared with the control values, similarly at about 3 h after administration, and returning to its initial level by 4 h, and rising to a second peak, about one-third of the magnitude of the first, about 25 h after the injection. The effect in the adrenal gland of the mouse was multiphasic, reaching its maximum, 94-fold enzyme activity compared with the control values, 7--8 h after treatment.