PubMed · 7023205
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
R C Elston. 1981. Segregation analysis.. https://doi.org/10.1007/978-1-4615-8303-5_2
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
A series of 6-alkylaminopyridazine-3-carboxylic acid derivatives was tested for dopamine beta-hydroxylase inhibitory activity in vitro according to the method of Kruse et al. Methyl 6-alkylaminopyridazine-3-carboxylates (4) were synthesized through the reaction of methyl 6-chloropyridazine-3-carboxylate (1) with ammonia followed by the condensation with primary amines, and by the methanolysis of the resulting 6-alkylaminopyridazine-3-carboxamides (3) in methanol in the presence of boron trifluoride etherate. Among tested compounds, 6-benzylaminopyridazine-3-carboxylic acid was found to have the most potent inhibitory activity, which was in the same level of the activity of fusaric acid.
Dopamine beta-monooxygenase is shown to catalyze the oxidation of N,N,N',N'-tetramethyl-1,4-phenylenediamine (TMPD) to its cation radical in the presence of a regular substrate and molecular oxygen. The enzyme-mediated oxidation of TMPD is stoichiometrically coupled with the hydoxylation of the substrate to the corresponding enzymatic product. TMPD is kinetically well behaved as an alternate electron donor for the enzyme with a potency comparable to that of the most efficient electron donor, ascorbate. Dopamine beta-monooxygenase mediated oxidation of TMPD has been employed to design a convenient and sensitive spectrophotometric assay for the enzyme. The finding that TMPD is a well behaved facile alternate electron donor for dopamine beta-monooxygenase raises some interesting novel questions regarding the specificity and chemistry of the reduction site, which may have important implications on the reduction of active site coppers of the enzyme.
The course and distribution of neuropeptide Y (NPY)-immunoreactive (ir) nerves in the human liver was studied using immunohistochemistry. The distribution and density of NPY-ir fibers was compared with tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) immunoreactivity, two enzymes which are markers for dopamine- and noradrenaline-synthetizing neurones. NPY-immunopositive nerve fibers were densely distributed in the perivascular plexus of the portal trials, along the vena centralis, as well as close to the sinusoids and hepatocytes. The distribution of perivascular TH-ir and DBH-ir nerve fibers was similar to that of NPY-ir nerves, with the exception of intralobular nerves, where close topographical relations to individual hepatocytes and sinusoids were rarely observed. These results suggest that NPY is present in noradrenergic perivascular nerve fibers; probably of sympathetic origin and also in other parasympathetic, presumably cholinergic nerve fibers around the sinusoids.