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The effect of exogenous administration of glutamic acid (GL), aspartic acid (A) and glycine (G) on individual amino acids in the free amino acid pool was studied in skeletal muscles of 60- to 70-day-old normal (N) and dystrophic (D) mice. Both N and D mice received either 0.25 ml of saline (S) or 250 mg/kg weight of GL, A or G in 0.25 ml S subcutaneously for 13 days. GL, A, G or S did not cause any significant changes in the body and skeletal muscle weights of either group. Most of the individual amino acids were increased in skeletal muscles of GL-treated mice and were decreased in A- or G-treated animals compared to S administration in the N group. The picture was more dramatic in the D group: GL-induced amino acid elevations were more pronounced than the values of N- or S-treated D controls. A and G elicited amino acid increases in D mice compared to their S-treated counterparts. Most of the individual amino acids in skeletal of the D group were decreased relative to N mice after S, GL or A administration. This was evident when the D/N ratio was calculated for S, GL and A. The situation was very different after G administration since of the individual amino acids were augmented in the skeletal muscle of D mice compared to N animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Two sets of experiments were performed to investigate the nonantioxidant functions of alpha-tocopherol. Eighteen rabbits in the first set and 48 rabbits in the second set were equally divided into three groups. The first group received a basal tocopherol-deficient diet supplemented with all-rac-alpha-tocopherol for 3 wk and the second group was fed the basal diet. The third group received vitamin E supplementation for 1 wk after 2 wk of consuming a tocopherol-deficient diet. In the first set of animals, skeletal muscle concentration, metabolism and turnover of various adenine nucleotides were measured by incubating the muscles of the three groups with [8-3H]adenine. The second set of experiments investigated in vivo concentration of various adenine nucleotides before incubation with radioactive substrate and quantity of newly formed adenine nucleotides after incubation with four different specific radioactive substrates: [8-14C]ATP; [8-14C]cAMP; [8-14C]5'AMP and [8-14C]adenosine. The results expressed per milligram of DNA were compared between the tocopherol-supplemented and tocopherol-deficient rabbits. Cyclic-AMP concentration (measured after a 2-h incubation with [8-3H]adenine) was lower and 5'-AMP concentration was very high in the tocopherol-deficient rabbits. The results of incorporation studies indicated that the turnover of ATP + ADP, cAMP, 5'-AMP and adenosine was higher in the tocopherol-deficient rabbits. Administration of tocopherol to tocopherol-deficient rabbits restored the turnover of cAMP to nearly normal values. These observations provided new insights concerning nonantioxidant functions of alpha-tocopherol.

We studied the effects of graded dietary restriction on the amount and translatability of messenger RNA (mRNA) molecule coding for brain proteins during the developmental period of life. Control experiments were performed on new born, 1-, 3-, 6- and 27-week-old rats, whereas the dietary restriction studies, involving 10, 30 or 50% food deprivation, were conducted on weanling rats for periods of 3 or 24 weeks. Graded dietary restriction for 3 or 24 weeks caused a progressive reduction of the amount and translatability of mRNA in the rat brain. Complementary DNA (cDNA) probe and hybridization studies with (3H)cDNA revealed that food depriva tion elicited a shorter species of mRNA or shorter sequences of the same species of mRNA coding for brain proteins and that not all polyadenylates mRNA (poly(A)+ mRNA) sequences found in control rats were present in the dietary-restricted animals. Furthermore, it appeared that food deprivation produced a shorter species of pre- mRNA via decreased polynucleotide elongation. The mRNA content of 27-week-old rat brains increased 12.5 times in comparison to newborns, representing an augmenta tion that was progressive and related to the developmental period of life of the ani mals. The translatability of mRNA was enhanced in the brain of 3-week-old rats, as compared to 1-week-old pups, and did not show any change thereafter. From these studies, it can be concluded that graded dietary restriction considerably modified the metabolism of mRNA in the rat brain, whereas minor alterations occurred during the developmental period of life in control animals. J. Nutr. 114: 2353-2364, 1984. INDEXING KEYWORDS brain messenger RNA • content • translatability • developmental age • dietary restriction

The distribution of radioactivity in the rat has been studied following the administration of ionic 111In CI3, and of chelates of 111In with lactic, citric and acetic acids, HEDTA, bleomycin and TPP. The ionic form is excreted least, and HEDTA and bleomycin most, the others being intermediate. Allowing for differences in excretion there is no significant difference in the distribution in normal tissues of the retained part of any of the compounds studied, with the exception of TPP which gave high levels in the liver.

Variations in the content and translatability of the poly(A)+ RNA and mRNA molecules coding for myosin (M) were studied in the hind leg muscles of genetically dystrophic mice. The poly(A)+ RNA content of total skeletal muscle failed to increase normally during progression of the disease. M mRNA, isolated from dystrophic murine muscle poly(A)+ RNA, was mostly found to be associated with the 26S RNA species. The translation of M mRNA in an in vitro heterologous wheat germ system was lower at 8 and 16 weeks in the dystrophic group as compared with the controls. Analysis of the translation products via sodium dodecyl sulfate – polyacrylamide gel electrophoresis, autoradiography, and densitometric autoradiographic tracing demonstrated the gradual disappearance of a protein band corresponding to M, the major component of skeletal muscle. cDNA was synthesized, using M mRNA that was isolated and purified from normal and dystrophic mouse muscle as a template. Total radioactivity was measured in some cDNA fractions produced from normal and dystrophic mouse muscle, while other fractions were utilized for separation and sizing of cDNA by disc gel electrophoresis. The cDNA from normal muscle was hybridized with M mRNA from normal and 16-week-old dystrophic mouse muscles. The cDNA probe, hybridization experiments, and studies involving the content and synthesis of M mRNA suggest that murine muscular dystrophy elicited a shorter species of mRNA or shorter sequences of the same species of mRNA coding for M. Not all poly(A)+ mRNA sequences coding for M, found in control mice, were present in their dystrophic counterparts. In conclusion, it appears that murine muscular dystrophy produces a shorter species of pre-M mRNA via decreased polynucleotide elongation.

Mitochondria specific dye, rhodamine-123 (Rh-123), has been labeled with radioactive iodine and tissue distribution of the radiolabeled product has been studied in mice. Transplantable KHT sarcoma and a spontaneous adenomammary carcinoma served as tumor models. The FAB mass spectra of iodinated Rh-123 indicated that mono and di-iodo products were formed which, as shown by other in vitro tests, were positively charged, and were heavily taken up by the mitochondria of living cells in culture. In animals, it was observed that, initially the radioactivity was taken up by all major organs from which it cleared rapidly including that from the KHT sarcoma; but not from the spontaneous adenomammary carcinoma. As a result, the spontaneous tumors retained much higher radioactivity than the equal weight of blood (×4.3) or muscle (×9.5), and were unequivocally detectable by extermal scintigraphy. The mitochondria selectivity and the specificity of the radioiodinated Rh-123 for the tumors of epithelial origin are exciting and warrant further studies of its use in diagnosis and therapy.