Structure and subunit composition of GABA(A) receptors.

GABA(A) receptors are the major inhibitory neurotransmitter receptors in the brain and are the site of action of many clinically important drugs. These receptors are composed of five subunits that can belong to eight different subunit classes. If all GABA(A) receptor subunits could randomly combine with each other, an extremely large number of GABA(A) receptor subtypes with distinct subunit composition and arrangement would be formed.

Establishment of a continuous cell line from a human carcinoid of the small intestine (KRJ-I).

A new continuous cell line from a human malignant carcinoid of the small intestine (KRJ-I) was established. The cells showed morphological and immunocytochemical features of the tumor of origin and expressed estrogen receptors. The cells are growing as a suspension, forming multicellular aggregates and spheroids.

Reduced tumour incidence in mice with inherited seborrhoeic dermatitis.

121 mice homozygous for the gene seb (inherited seborrhoeic dermatitis) and their 142 unaffected heterozygous littermates were kept for their natural lifespan. Heterozygotes showed 84.1% total tumour incidence in males and 95.

Creatine reduces collagen accumulation in the kidneys of diabetic db/db mice.

In the present study, we tested the hypothesis whether creatine, a metabolite of arginine metabolism, shares the pharmacological activities of arginine reducing collagen accumulation in the diabetic kidney. Ten db/db mice were given, for 3 months, a solution containing a daily dosage of creatine of 50 mg/kg body weight. Eleven db/db mice served as controls.

New continuous cell-line from human medullary-thyroid carcinoma - sinj - phenotypic analysis and invivo carcinogenesis.

SINJ is a new continuous human cell line derived from a lymph node metastasis of a probably sporadic medullary thyroid carcinoma. It is compared to MTC-SK, another medullary thyroid carcinoma cell line, established earlier (1). SINJ has been continuously cultivated in vitro for two years.

Evidence for the existence of differential O-glycosylated alpha 5-subunits of the gamma-aminobutyric acidA receptor in the rat brain.

Polyclonal antibodies were raised to synthetic peptides having amino acid sequences corresponding with the N- or C-terminal part of the gamma-aminobutyric acidA (GABAA) receptor alpha 5-subunit. These anti-peptide alpha 5(2-10) or anti-peptide alpha 5(427-433) antibodies reacted specifically with GABAA receptors purified from the brains of 5-10-day-old rats in an enzyme-linked immunosorbent assay and were able to dose-dependently immunoprecipitate up to 6.3 or 13.

N-deglycosylation and immunological identification indicates the existence of beta-subunit isoforms of the rat GABAA receptor.

beta 2- and beta 3-subunits of GABAA receptors purified from the brains of 5-10-day-old rats were investigated in the intact or completely N-deglycosylated state using the beta-subunit-specific monoclonal antibody bd-17 and polyclonal antibodies directed against synthetic amino acid sequences specific for the GABAA receptor beta 2- or beta 3-subunits. The present results seem to indicate the existence of two different isoforms of the beta 3-subunit and several different isoforms of the beta 2-subunit of the GABAA receptor which probably are produced by alternative splicing.

Biological activity of alpha-alkyl-amino acids.

A series of alpha-alkyl-amino acids were tested for some biological functions in the mouse (OF-1 Himberg) by adding them to the animal chow (30 mg/kg/day) for a period of six weeks. No differences in fluid or food uptake could be observed during the feeding period, as compared to a control group. Histology of liver and kidney did not show any changes.

[The tumor spectrum of Him:OFA rats].

The longevity and incidence of spontaneous tumors was investigated in 92 male and 182 female rats of the Sprague-Dawley (SD) derived stock Him: OFA. The overall tumour incidence was 85.9% in males and 97.

Identification of alpha 2- and alpha 3-subunits of the GABAA-benzodiazepine receptor complex purified from the brains of young rats.

Polyclonal antibodies were raised to synthetic amino acid sequences of the bovine GABAA receptor alpha 2- and alpha 3-subunits and purified by affinity chromatography on a column coupled with the respective peptide. Anti-peptide alpha 2(416-424) and anti-peptide alpha 3(459-467) antibodies immunoprecipitated GABAA receptors and recognized a protein of 53 kDa (P53) and 59 kDa (P59), respectively, in Western blots of GABAA receptors purified from the brains of 5-10 day old rats. P53 as well as P59 are specifically photolabeled by [3H]flunitrazepam and are recognized by the alpha-subunit specific monoclonal antibody bd 28.

The effect of substance L on glucose-mediated cross-links of collagen in the diabetic db/db mouse.

Genetically diabetic mice (db/db) were given 50 mg/kg body weight/day substance L, a nontoxic basic amino acid and compared to control diabetic mice without treatment. The oral administration of the compound was started at the age of 3 months and the animals were sacrificed at the age of 7 months. No adverse effects were observed in animals given the substance L.

Inherited seborrheic dermatitis--a new mutant in mice.

A new mutation, affecting skin and hair, occurred in an expansion colony of Him:OF1 mice. Test crosses showed that a single autosomal recessive gene was responsible for this trait. Homozygotes have sparse greasy fur and lower viability and fertility than normal littermates.

[Effect of superoxide dismutase on an arthritis model in the rabbit. A scanning electron microscopy study].

The effect of superoxide dismutase (SOD) was studied in an experimental arthrosis model (fixation arthrosis in rabbits). Out of a total of 40 animals, 20 of which were to be treated with SOD and 20 with placebos, 5 animals each were given padded stiffened bandages to immobilize their right knee joints for 1 week, 2 weeks, 3 weeks and 4 weeks respectively. After removing the bandage and a two-week recovery period the SOD or placebo treatment respectively was begun.

Induction of arthritic processes by synovial fluids of rheumatoid arthritis patients in long-term experiments with mice.

Diluted synovial fluids derived from three patients with rheumatoid arthritis (RA) and applied subcutaneously once as a single dose in Swiss mice caused arthritic processes after a long period of latency (10 months). The arthritis-inducing effect was enhanced by storing the original synovial fluids at 4 degrees C for three months. The effects were followed histologically for at least 18 months.

Effects of burns on amino acid levels in rat plasma, liver and muscle.

In this study the influence of a severe catabolic situation (scalding and nitrogen deprivation) on amino acid (AA) metabolism was investigated in an experimental rat model. Scalding of 25 per cent of the total body surface area (TBSA) and hypocaloric alimentation (5.6 kcal per 100 g rat per day, no nitrogen) resulted in mean daily nitrogen losses of -0.

[Histologic studies of the effect of superoxide dismutase on an arthrosis model in rabbits].

The effect of the enzyme superoxide dismutase (SOD) on experimentally induced osteoarthritis was investigated. Immobilization of the right knee of rabbits over variable periods (1-4 weeks) was used as the model for the study. SOD was applied intraarticularly.

The effect of a cartilage bone marrow extract on experimentally induced osteoarthrosis in the knee joints of rabbits. A scanning electron microscopic study.

The development of osteoarthrosis following a partial meniscectomy on the knee cartilage of rabbits (Chinchilla hybrids) was monitored with a scanning electron microscope. Simultaneously, a study was made of the effect of the cartilage bone marrow extract Rumalon trademark on the development of the osteoarthrotic changes. Twelve days after the operation, osteoarthrotic changes were evident in the untreated operated joints.