ABSTRACT
Injuries to the extremities from stingray barbs are not uncommon along the Australian seaboard. Cardiac injuries from stingray barbs are rare, even worldwide, and all but one have been fatal. We report a survivor of a cardiac injury caused by a stingray barb. Penetration of a body cavity by a stingray barb requires early surgical referral and management.
Subject(s)
Bites and Stings/physiopathology , Coronary Vessels/injuries , Heart Injuries/etiology , Skates, Fish , Adult , Animals , Bites and Stings/therapy , Heart Injuries/surgery , Humans , Male , Pericardial Effusion/etiology , Treatment OutcomeSubject(s)
5-Hydroxytryptophan/pharmacology , Brain/metabolism , Dihydroxyphenylalanine/pharmacology , Dopamine/metabolism , Polyribosomes/metabolism , Receptors, Drug , Serotonin/metabolism , Animals , Apomorphine/pharmacology , Aromatic Amino Acid Decarboxylase Inhibitors , Binding Sites , Brain/drug effects , Brain/ultrastructure , Cyproheptadine/pharmacology , Enzyme Inhibitors/pharmacology , Female , Haloperidol/pharmacology , Heart/drug effects , Male , Methysergide/pharmacology , Myocardium/metabolism , Pimozide/pharmacology , Polyribosomes/drug effects , Polyribosomes/ultrastructure , RatsABSTRACT
Brain polysomes are disaggregated in rats given moderate to large doses of d-amphetamine sulfate; this response is rapid in onset, lasts for at least 4-6 hr, and varies with the age of the animal. Pretreatment with a dopamine receptor blocking agent, haloperidol or pimozide, blocks the amphetamine-induced disaggregation.
Subject(s)
Brain/ultrastructure , Dextroamphetamine/pharmacology , Dopamine/metabolism , Polyribosomes/drug effects , Receptors, Drug , Animals , Brain/metabolism , Dextroamphetamine/antagonists & inhibitors , Haloperidol/pharmacology , Male , Pimozide/pharmacology , RatsSubject(s)
Brain/metabolism , Dihydroxyphenylalanine/pharmacology , Leucine/metabolism , Nerve Tissue Proteins/biosynthesis , Protein Biosynthesis/drug effects , Animals , Brain/cytology , Brain/drug effects , Carbon Radioisotopes , Centrifugation, Density Gradient , Chromatography, Ion Exchange , Kinetics , Lysine/metabolism , Male , Polyribosomes/drug effects , Polyribosomes/metabolism , Rats , Ribosomes/metabolism , Time FactorsSubject(s)
Brain/drug effects , Levodopa/pharmacology , Nerve Tissue Proteins/biosynthesis , Polyribosomes/drug effects , 5-Hydroxytryptophan/pharmacology , Animals , Aromatic Amino Acid Decarboxylase Inhibitors , Brain/metabolism , Brain/ultrastructure , Carbon Radioisotopes , Decarboxylation , Depression, Chemical , Dihydroxyphenylalanine/metabolism , Dihydroxyphenylalanine/pharmacology , Dopamine/metabolism , Drug Interactions , Enzyme Inhibitors/pharmacology , Hydrazines/pharmacology , Leucine/metabolism , Lysine/metabolism , Male , Methyldopa/metabolism , Norepinephrine/metabolism , Norepinephrine/pharmacology , Rats , S-Adenosylmethionine/metabolism , Time FactorsABSTRACT
The disaggregation of brain polysomes which is produced by giving large doses of (L)-dopa to rats is not reproduced by administering its metabolite, 3-O-methyldopa, by giving D-dopa, which also depletes the brain of S-adenosylmethionine but is not converted to catecholamines, or by giving the L-dopa after a decarboxylase inhibitor. Polysome disaggregation is potentiated by the prior administration of a monoamine oxidase inhibitor, indicating that formation of a catecholamine is an obligatory requirement. These observations suggest that the mechanism by which L-dopa disaggregates brain polysomes involves its conversion to dopamine within the majority of brain cells.
Subject(s)
Brain/drug effects , Dihydroxyphenylalanine/pharmacology , Dopamine/pharmacology , Ribosomes/drug effects , Animals , Benzyl Compounds/pharmacology , Brain/cytology , Brain/metabolism , Brain Chemistry , Carboxy-Lyases/antagonists & inhibitors , Dihydroxyphenylalanine/administration & dosage , Dihydroxyphenylalanine/analysis , Dihydroxyphenylalanine/metabolism , Dopamine/analysis , Hydrazines/pharmacology , Injections, Intraperitoneal , Male , Methyldopa/administration & dosage , Methyldopa/analysis , Methyldopa/pharmacology , Norepinephrine/analysis , Norepinephrine/pharmacology , Rats , Rats, Inbred Strains , S-Adenosylmethionine/analysis , Serine/pharmacologyABSTRACT
One hour after administration of L-dopa (50 to 300 milligrams per kilogram), there is a marked disaggregation of brain polysomes in immature rats. Adult animals show a similar response, but require larger doses of the amino acid (500 milligrams per kilogram). Single doses of L-dopa significantly elevate amounts of tryptophan in the brain; hence their effect on polysomes does not result from the unavailability of this amino acid.
