title: Dopamine-beta-hydroxylase activity in the axillary bodies, the heart and the splanchnic nerve in two elasmobranchs, Squalus acanthias and Etmopterus spinax.
abstract: 1. The activity of dopamine-beta-hydroxylase (DBH) was examined in tissues from Squalus acanthias and Etmopterus spinax using tyramine as substrate. 2. The activity of DBH in axillary bodies in Squalus was 19040 +/- 240 nmol/g per hr and in Etmopterus 6120 +/- 245 nmol/g per hr. 3. DBH activity in nervous tissue, i.e. the splanchnic nerve (together with coeliac artery) was found to be 123 +/- 41 nmol/g per hr in Squalus and 384 +/- 62 nmol/g per hr in Etmopterus. 4. In Squalus heart DBH activity was undetectable, while Etmopterus heart had DBH activity both in atrium and ventricle, 40 +/- 13 and 18 +/- 8 nmol/g per hr respectively. 5. A small amount of DBH activity was found in Squalus blood plasma, 2 +/- 0.7 nmol/ml per hr. 6. The DBH activity gave high formation of octopamine in a wide temperature range from 24.5 to 32 degrees C.
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000096:biosynthesis; D002838:Chromaffin System / Q000201:enzymology; D004284:Dogfish / Q000378:metabolism*; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism*; D005260:Female; D005399:Fishes / Q000378:metabolism*; D005728:Ganglia, Sympathetic / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D009206:Myocardium / Q000201:enzymology*; D012754:Sharks / Q000378:metabolism*; D013153:Splanchnic Nerves / Q000201:enzymology*; D013696:Temperature
chemical_list: D002395:Catecholamines; D004299:Dopamine beta-Hydroxylase