Two-dimensional electrophoresis of rat serum esterases in cellulose acetate and acrylamide gradient gel

Zusammenfassung Isoenzyme von Serumesterasen wurden zuerst mit Zelluloseazetat und dann mit einem Gradientgel von Polyakrylamid mit zweidimensionaler Elektrophorese bei der Ratte untersucht. Ein neues Band, das eine starke Albuminesteraseaktivität aufweist und unempfindlich gegen 10^–3 M Physostigmin ist, wurde somit gefunden. Von 17 Esterasebändern waren 7 empfindlich auf Physostigmin, und 3 wurden auch durch Iso-OMPA gehemmt, während 284-C-51 gar keinen Effekt zeigte.

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Supported by a grant from the Sigrid Jusélius Foundation, Finland.     

Stimulation of histamine synthesis in rat mast cells by compound 48/80 in vitro

The histamine content of rat peritoneal fluid cells is doubled within 20 min by 0.5 microgram/ml of compound 48/80. Histamine catabolism inhibitors do not reproduce this effect; cells pre-incubated with alpha-fluoromethylhistidine are unresponsive to compound 48/80 which therefore activates pre-formed histidine decarboxylase rather than 'inducing' it. Non-mast cells showed no change after treatment with compound 48/80.     

A dopamine- and cyclic AMP-regulated phosphoprotein enriched in dopamine-innervated brain regions

Several mammalian neurotransmitter candidates, for example, serotonin, dopamine and noradrenaline, may exert some of their synaptic effects by regulating protein phosphorylation systems. Comparison of the regional distribution of brain phosphoproteins with neurotransmitter systems may help to identify the specific phosphoproteins involved in the functions of particular neurotransmitters. Here we report the association of one such phosphoprotein with the dopamine pathways in brain. This protein, of apparent molecular weight (MW) 32,000 (32K), seems to be present only in nervous tissue. Its regional distribution within the brain is very similar to the pattern of dopamine-containing nerve terminals; more specifically, the protein appears to be enriched in those dopaminoceptive neurones which possess D-1 receptors (dopamine receptors coupled to adenylate cyclase). The state of phosphorylation of the protein in these dopaminoceptive neurones can be regulated by both dopamine and cyclic AMP. These results suggest that the phosphoprotein may mediate certain of the trans-synaptic effects of dopamine acting on dopaminoceptive neurones.     

Mapping of an endogenous retroviral sequence to human chromosome 18

The application of recombinant DNA technologies has allowed the detection of at least three families of moderately repetitive DNA segments in the human genome that are homologous to retroviruses previously isolated from mice and primates. One of these DNA segments has been shown by nucleotide sequence comparisons to be distantly related to both Moloney murine leukaemia virus (MoMuLV) and the endogenous baboon retrovirus and to have the sequence organization characteristic of an integrated retrovirus. Isolation of the homologous locus from chimpanzee DNA indicated that the integration event preceded the evolutionary divergence of chimpanzees and man. Here we have used a panel of rodent x human somatic cell hybrids to assign the chromosomal localization of this segment, called ERV1 (endogenous retrovirus-1), to human chromosome 18 (HSA 18).     

A DNA insertion in the apolipoprotein A-I gene of patients with premature atherosclerosis

Apolipoprotein A-I (apo A-I) is the major protein constituent of high-density lipoprotein (HDL). The study of the apo A-I gene is of interest because plasma levels of HDL have been inversely correlated with the development of coronary artery disease and because polymorphisms related to this gene have been associated with hypertriglyceridaemia and premature atherosclerosis. We have recently isolated and characterized the human apo A-I gene and have shown that apo A-I and apolipoprotein C-III (apo C-III) genes are physically linked and that a polymorphism (of unknown frequency in the general population) of the apo A-I gene is inherited as a mendelian trait linked to premature atherosclerosis in an affected family (not the same polymorphism as has previously been reported to be associated with hypertriglyceridaemia). Here we report that this polymorphism is due an at least 6.5-kilobase (kb) DNA insertion in the coding region of the apo A-I gene and that there is no detectable alteration (as determined by limited genomic blotting analysis) of the apo C-III gene of these patients.     

Characterization and antithrombotic action of tissue plasminogen activator

Summary An extractive fibrinolytic enzyme has been characterized and found to belong to the class of vascular plasminogen activators. The agent has been found to have an antithrombotic action in the rabbit.Provided by Dr L. Dussourd d'Hinterland, Laboratoires Pierre Fabre, Castres, France. 1000 units have a fibrinolytic activity of about 15 PU urokinase.