Nineteen tyrosine auxotrophs of the ciliated protozoan Tetrahymena thermophila have been isolated and biochemically examined. These mutants are defective in the conversion of phenylalanine to tyrosine; this is analogous to the defect that causes phenylketonuria in humans. After nitrosoguanidine mutagenesis and self-fertilization, progeny clones were screened for tyrosine auxotrophy and positive...

By screening of culture filtrates of fungi and streptomyces for activity in inhibit dopa decarboxylase the following isoflavone compounds were obtained: psi-tectorigenen (I), genistein (II), orobol (IV), 8-hydroxygenistein (V) and a new compound (III). III was elucidated to be 3', 4', 5, 7-tetrahydroxy-8methoxy isoflavone. Among these isoflavones, IV and III showed the strongest activity in inh...

We report that two isoforms of Drosophila tyrosine hydroxylase protein are encoded via alternatively spliced exons. The major isoform (Type II) contains a novel acidic extension of 71 amino acids in the amino-terminal regulatory domain, which is likely to alter the regulatory properties of the tyrosine hydroxylase protein. The minor isoform (Type I) corresponds to the cDNA sequence reported pre...

Robert H. Roth, Phyllis M. Salzman and Victor H. Morgenroth, III Departments of Pharmacology and Psychiatry Yale University School of Medicine New Haven, Connecticut 06510 Communicated by: Parkhurst A. Shore (Received B July 1974; accepted 23 July 1974) In peripheral noradrenergic neurons an increase in impulse flow results in an acceleration of norepinephrine biosynthesis. This increase in tra...

The influence of serotonin afferents on tyrosine hydroxylase expression in differentiating neurons of the rat arcuate nucleus was studied in vivo and in vitro. In the in vivo study, pchlorophenylalanine inhibited serotonin synthesis in fetal brain from the 11th to the 20th embryonic day. We then used semiquantitative immunocytochemistry to evaluate tyrosine hydroxylase levels in neurons of the ...

Renal ischemia produces renal sympathoexcitation that is responsible for the development of ischemic acute kidney injury. The present study examined changes in the sympathetic nerve function in mice. Ischemic acute kidney injury was induced by occlusion of both renal pedicles. Renal ischemia/reperfusion increased blood urea nitrogen and plasma creatinine and expression of tyrosine hydroxylase, ...

Regulation of tyrosine hydroxylase expression by antidepressant treatments was investigated in the locus coeruleus (LC), the major noradrenergic nucleus in brain. Rats were treated chronically with various antidepressants, and tyrosine hydroxylase levels were measured in the LC by immunoblot analysis. Representatives of all major classes of antidepressant medication-including imipramine, nortri...

After demonstration of the decarboxylation of 3,4-dihydroxyphenylalanine (dopa)’ to dopamine (I), the pathway for biosynthesis of norepinephrine shown in Fig. 1 was proposed. Although evidence for this pathway was well established by isot,opic procedures (2, 3), it was not until 1960 that Levin, Levenberg, and Kaufman (4) succeeded in isolating and characterizing the third enzyme in the series,...

BACKGROUND Sensitive monitoring of minimal residual disease may improve the treatment of neuroblastoma in children. To detect and monitor neuroblastoma cells in blood and bone marrow, we developed a quantitative method for the analysis of tyrosine hydroxylase mRNA. METHODS We used real-time reverse transcription-PCR. The calibrator was constructed from a segment of tyrosine hydroxylase mRNA t...

The effect of repeated administration of 3,4-methylenedioxymethamphetamine (MDMA) on the expression of tyrosinc hydroxylase and preprocholecystokinin (CCK) messenger RNAs in substantia nigra was examined by in situ hybridisation histochemistry. Sections hybridised with 35S-labelled oligonucleotides were subjected to computerised image analysis to determine the densiw of silver grains above posi...