Comments on testing for equivalence.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
Michael Bruss
Publications and source records attributed to Michael Bruss.
Identification and pharmacological characterization of a specific agmatine transport system in human tumor cell lines.
Specific accumulation of [(14C)]agmatine in six human intestinal tumor cell lines and in the glioma cell line SK-MG-1 was inhibited by phentolamine, idazoxan, clonidine, 1,3-di-(2-tolyl)guanidine, histamine, putrescine, spermine and spermidine. Corticosterone, desipramine, O-methylisoprenaline, cirazoline, moxonidine, l-arginine, l-lysine, verapamil, nifedipine, CdCl(2), ondansetron, and l-carnitine failed to inhibit specific [(14)C]agmatine accumulation, thus excluding that it is mediated by amino acid or monoamine carriers, by the putrescine carrier, by 5-HT(3) receptor channels, by Ca(2+) channels or by the organic cation transporters OCT1, OCT2, OCT3, OCTN1, or OCTN2. This conclusion is supported by the finding that transfection of HEK293 cells with cDNA encoding either hOCT1, hOCT2, or hOCT3 did not enhance specific [(14)C]agmatine accumulation compared to nontransfected cells. The data suggest that agmatine is accumulated by a specific agmatine transporter. Since incubation with exogenous agmatine for 24 hours increased intracellular agmatine content in all cell lines by a multiple of the basal endogenous content, the agmatine uptake system may be relevant for the regulation of the intra- and extracellular concentration of agmatine in humans.
Agmatine↗
Alpha(2A)-adrenergic versus imidazoline receptor controversy in rilmenidine's action: alpha(2A)-antagonism in humans versus alpha(2A)-agonism in rabbits.
At the alpha(2A)-autoreceptors on the sympathetic nerve terminals of the human atrial appendages and rabbit pulmonary artery, rilmenidine and oxymetazoline exhibit different properties (antagonism and agonism, respectively). These opposite pharmacodynamic properties of alpha(2)-adrenoceptor ligands seem to be due to substantial differences in the nucleotide and amino acid sequences between human and rabbit alpha(2A)-adrenoceptors. Hence, the rabbit alpha(2A)-adrenoceptor is not reliably predictive for the action of ligands at the human alpha(2A)-adrenoceptor.
Adrenergic alpha-Agonists↗