Inborn errors of carnosine and homocarnosine metabolism.

Serum carnosinase deficiency with carnosinuria has been reported in 23 children with neurological signs and/or mental retardation. In adults four cases in one family had serum carnosinase deficiency, carnosinuria, and in addition elevated homocarnosine in CSF and in the brain. The mother was one of these cases but had no clinical symptoms; however her three children have spastic paraparesis, retinitis pigmentosa and mental retardation. Serum carnosinase deficiency alone is not the cause of the neurological symptoms. When two of the affected children consumed carnosine, anserine or homocarnosine, they metabolized these compounds much less rapidly than did two normal control individuals.

Fasting plasma amino acid concentrations in PKU children on two different levels of protein intake.

Two groups of children with phenylketonuria were treated with different amounts of protein. One group (RDA group) received protein as recommended by the U.S. Food and Nutrition Board, the other (FAO group) the amount recommended by the FAO/WHO 1973 ad hoc Expert Committee. Two of the children in the FAO group showed a decrease in length/growth velocity which raised the question of the adequacy of the protein content in the diet. Since deviations from normal plasma amino acids have been observed in protein deficient, energy-adequate diets, we examined these parameters in the PKU children. In the two children with retardation in length/growth, very high glycine values as well as very high alanine values were observed at the end of the study. These observations strengthened our suspicion that the FAO/WHO 1973 recommendations are marginal.

Cystathioninuria in a profoundly mentally retarded woman with spastic tetraplegia, deafness and abnormal liver function tests.

This article describes a profoundly mentally retarded woman with spastic tetraplegia, deafness and abnormal liver function tests with a secondary cystathioninuria. The cystathioninuria could be corrected with vitamin B6 supplementation.

A double-blind comparison of citalopram (Lu 10-171) and amitriptyline in depressed patients.

In a controlled, clinical, multicentre trial comprising a total of 43 patients (17 men and 26 women) citalopram was compared double-blindly with amitriptyline. Nineteen patients of each group were classified as endogeneously depressed, whereas four patients of the citalopram group and one of the amitriptyline group were classified as non-endogenously depressed. The patients were seriously ill with a high frequency of previous depressive episodes and of mental disorders among their closest relatives. Thirteen of the patients in either group had received antidepressants without satisfactory effect before entry into the trial. Each patient was treated for a period of at least 3 weeks with daily citalopram doses of 30-60 mg or daily amitriptyline doses of 75-225 mg. A statistically significant reduction of MADRS scores (total scores as well as each of the 10 individual items) was recorded in both groups. The only difference between the groups was a trend towards a better effect on sleep disturbances in the amitriptyline group. Side-effects were recorded more frequently in the amitriptyline group than in the citalopram group, global assessment of side effects being significantly different in favour of citalopram. It is concluded that citalopram is an effective and safe drug in the treatment of endogenous depression - probably as efficacious as amitriptyline, but with fewer side effects.

Homocarnosinosis: influence of dietary restriction of histidine.

Homocarnosinosis, an inherited disorder, is characterized by an elevated level of the dipeptide homocarnosine (Hca) in the CSF and the brain and, in addition, by carnosinuria and serum carnosinase deficiency. In three children with homocarnosinosis the biochemical aberration co-exists with paraplegia, retinitis pigmentosa, and a progressive mental deficiency. In the mother, however, only the biochemical aberration was present without clinical symptoms. In order to study whether this elevated level of Hca and increased excretion of carnosine (Car) could be reduced towards normal, a dietary regiment with restriction of histidine (His) was maintained for nearly 2 1/2 years for two of the patients, 33 and 39 years old, with homocarnosinosis associated with neurological symptoms. His was reduced by about 90% in the CSF, in the plasma and in the urine. Within 5-6 months CSF Hca was reduced by about 70%, and urinary Car by 22 and 42%. The clinical neurological symptoms, however, did not alter significantly together with these biochemical changes.

A new patient with hyperornithinaemia, hyperammonaemia and homocitrullinuria treated early with low protein diet.

The characteristic biochemical disturbances of the amino acid and pyrimidine metabolism are described and illustrated by the first case of the HHH syndrome reported in Norway. The disorder was treated with a low protein diet at an early age and the patient developed normally on this diet.

Transport and distribution of homocarnosine after intracerebroventricular and intravenous injection in the rat.

Rats were injected intracerebroventricularly (i.c.v.) or i.v. with [14C]homocarnosine (250 nmol). Distribution of the dipeptide in brain structures, transport from the brain to the blood, distribution in peripheral organs, and excretion in the urine were studied by measuring radioactivity in tissue, plasma, and urine samples by liquid scintillation counting 15-120 min after injection. After i.c.v. injection, [14C]homocarnosine was taken up into all parts of the brain investigated (highest uptake in structures close to the site of injection), it was transported to the blood, and radioactive substances were found in low concentration in muscle, spleen, and liver, in high concentration in the kidneys, and very high concentration in the urine. Investigations using high pressure liquid chromatography (HPLC) showed that no degradation took place in the brain, all radioactivity was found in the homocarnosine fraction. In the plasma 86% of the radioactivity was found in the GABA fraction presumed to be formed by cleavage of the peptide.

Homocystinuria treated with pyridoxine.

Four cases of homocystinuria with lens luxation have been examined. As judged from the plasma amino acid pattern, they all responded well on pyridoxine treatment. Two of them discontinued the treatment on their own, and one of these died at the age of 17 years. The lens luxation progressed in one case despite adequate treatment. Scanning electron microscopy of one lens revealed partly broken zonules, abnormal zonular attachment, and a spongy appearance of the capsule proper. Hoping that adequate treatment will reduce more serious complications such as thromboembolism in these patients, it is concluded that an early diagnosis largely depends on the ophthalmologist, who should perform the silver-nitroprusside test, specific for homocystinuria, in all patients with non traumatic lens luxation.

Determination of ophidine in human urine.

Ophidine (beta-alanyl-3-methylhistidine) was first detected in the urine of two patients and later in two members of the laboratory staff loaded with whale meat, by column chromatography, high-voltage paper electrophoresis and two-dimensional paper chromatography. The ophidine peak was detected between homocarnosine and dimethylarginine using a lithium buffer gradient in column chromatography. In paper chromatography the ophidine spot was detected at a position close to anserine and homocarnosine. The ophidine in the urine from the patients was of dietary origin since it was absent in the urine a few weeks later.

Changes in plasma amino acid distribution and urine amino acids excretion during prolonged heavy exercise.

Venous plasma and urine amino acids and urea were measured in ten well-trained men, aged 23--45 years, in connection with a 70 km cross-country ski race, lasting 4.39--6.04 h, leading to slight dehydration. The estimated urea production rate during the race was of the order 7.6 mumol/min, kg b.wt, i.e. twice the rate for such men on ordinary protein intake, during ordinary activity, thus suggesting increased protein catabolism. The race led to a fall of the total plasma amino acid concentration to about 60% of the pre-race level. In particular, the branched chain amino acids (valine, iso-leucine, leucine) and alanine were markedly reduced, whereas the S-containing amino acids (taurine, cystine, methionine) and the aromatic (phenylalanine, tyrosine, trytophan, histidine) and glutamine/glutamate were increased, unchanged or only moderately reduced. It is concluded that prolonged heavy exercise is accompanied by increased protein catabolism and changes in the plasma amino acid concentrations similar to those observed during prolonged starvation, but differing from those seen at heavy exercise of less than 2 h duration or prolonged exercise of moderate intensity.

Amino acid concentrations in plasma and erythrocytes in aregeneratory and haemolytic anaemias.

The concentrations of unbound amino acids in erythrocytes and in plasma from 7 normal individuals, 11 patients with various types of aregeneratory anaemia, and 4 patients with hereditary haemolytic anaemias were determined on a Technicon Amino Acid Analyzer (Perry et al 1970). Most amino acids were normally found in higher concentrations in plasma than intracellularly. Cystine, methionine and trypotophan were almost exclusively present in plasma. Aspartic acid, however, was mainly found in erythrocytes, and glutathione only in erythrocytes. Glutamic acid and ornithine were more concentrated in the cells, while glycine and asparagine showed approximately the same concentrations in erythrocytes as in plasma. In the patients, plasma amino acids showed little deviations from normal, but in the erythrocytes there were striking changes. Erythrocyte glutamic acid concentrations were moderately to markedly elevated in all patients studied, and glycine concentrations in 13 out of 15 patients. In addition, the following amino acids were increased intracellularly in more than one patient: glutamine (8 patients), serine (7), asparagine (5), threonine (4), taurine (3), alanine (2), valine (2), ornithine (2), lysine (2), citrulline (2). Aspartic acid was decreased in erythrocytes from 4 patients with aregeneratory and 1 with haemolytic anaemia.

The switch mechanism in periodic catatonia and manic-depressive disorder.

Both in periodic catatonia and in manic-depressive disorders sudden switches occur in behavior, in the autonomic nervous system and in the catecholamine metabolism during the transition from interval or depression into catatonia or mania. Both the manic and the catatonic attacks seem to be superimposed on the basic depressive or schizophrenic illnesses. The attacks can be counteracted or suppressed by psychotropic drugs such as alpha-methyldopa, disulfiram, reserpine, haloperidol or chloropromazine which interfere with the catecholamine metabolism or their receptor sites. The involvement of the catecholamines may however be secondary to primary defects in the thyroid, the hypothalamus or the limbic system. The strict periodicity in periodic catatonia points to an accumulation of some active metabolite which may be produced centrally during the interval. At a certain level it may trigger the switch-mechanism and then be reduced during the catatonic phase. In periodic catatonia both the basic schizophrenic disease as well as the periodic manifestations are compensated by thyroxine-thyroid treatment.