SUMMARY Aim We investigated the effect of carbohydrate availability and euglycaemic hyperinsulinaemia on intramuscular and plasma amino acids in 14 healthy men (age 26.5 ± 0.9 years, b.m.i. 22.9 ± 0.5 kg/m2).Methods Insulin was infused (1.5 mU/kg/min) for 240 min both after a carbohydrate depleting exercise and after carbohydrate loading. Muscle samples were taken before and after hyperinsulinaemia. Plasma and intramuscular amino acid concentrations were measured.Results Insulin‐mediated glucose disposal was similar after carbohydrate depletion (65.2 ± 1.9 μmol/kg/min) and loading (66.9 ± 2.8 μmol/kg/min). Carbohydrate depletion was associated with decreased alanine and increased branched chain amino acid (BCAA) concentrations in muscle and plasma. Blood lactate was lower after carbohydrate depletion (477 ± 25 μmol/l) than loading (850 ± 76 μmol/l, p < 0.001). In carbohydrate depletion, hyperinsulinaemia resulted in a greater increase in intramuscular (from 927 ± 48 nmol/g muscle to 2029 ± 104 nmol/g muscle, p < 0.001), than plasma (from 197 ± 6.7 μmol/l to 267 ± 11 μmol/l, p < 0.001) alanine. After carbohydrate loading muscle alanine did not rise significantly (from 1546 ± 112 nmol/g muscle to 1781 ± 71 nmol/g muscle) whereas plasma alanine decreased (from 339 ± 26 μmol/l to 272 ± 13 μmol/l, p < 0.05).Conclusions (1) Carbohydrate availability has profound effects on the interrelationship between glucose and amino acid metabolism and on the form of storage for glucose‐derived carbons. (2) For most amino acids changes in plasma levels of amino acids are not related to changes in concentrations of intramuscular amino acids during hyperinsulinaemia.

The effects of intermittent (1 sec on/1 sec off) 45-Hz magnetic fields on quantitative electroencephalogram (EEG) were studied using 12 female rats. The animals were exposed for 24 hr to three different conditions: 1000 A/m (1.26 mT), 100 A/m (126 mu T), and sham exposure. The cortical EEG was recorded before and after each exposure, and the power spectrum of the EEG was calculated. Exposure at 100 A/m produced statistically significant decreases in the delta (1-4 Hz) and theta (4-8 Hz) bands and increased activities in the beta (12-20 Hz) and 30-60 Hz bands. Smaller changes were seen at 1000 A/m than at 100 A/m. The changes seen were more pronounced 15 min after the end of exposure than immediately after it. At 30 min after exposure most differences from the preexposure values had disappeared.

In a Finnish kindred consisting of 192 descendants from two marriages of a male ancestor born in 1868, the lumbar spines of 105 of the 170 living members were X-rayed. Spondylolysis was found in 22 individuals. In addition, six of them had spondylolisthesis, four had spina bifida occulta, and two had a transitional lumbar/sacral vertebra. Seven members of the kindred without spondylolysis had spina bifida occulta and 10 had transitional lumbar vertebrae. The pedigree is consistent with autosomal dominant inheritance and incomplete (about 75%) penetrance for spondylolysis. It raises the question of a common aetiology for several congenital disturbances in the formation of lumbar vertebrae and possibly supports the concept of variable expressivity of a "spondylolysis gene".