title: The metabolic effects of dopamine in man.
abstract: The metabolic effects of dopamine have been investigated by its infusion in normal man with and without simultaneous somatostatin administration. Dopamine was infused into overnight fasted men at 1.5 microgram/kg/min (n = 6) and 3.0 micrograms/kg/min (n = 5) for 120 min. Plasma dopamine concentrations at 120 min were 78 +/- 9 nmol/l and 117 +/- 17 nmol/l respectively, associated with a marginal rise in plasma noradrenaline. Dopamine (1.5 microgram/kg/min) induced an early and sustained rise in plasma glucagon (48 +/- 9 pg/ml versus 19 +/- 6 pg/ml in saline controls at 10 min, p less than 0.01) and a transient elevation in serum growth hormone which peaked to 17.7 (range 4.5-71.8) mU/l at 60 min (7.2 (range 0.6-37.7) mU/l with saline, p less than 0.05) but did not alter serum insulin, blood glucose or other metabolite levels. At 3.0 micrograms/kg/min, dopamine in addition provoked mild and transient elevations in blood glucose and serum insulin. Somatostatin (250 micrograms/h) suppressed circulating insulin, glucagon, and growth hormone levels and abolished the small hyperglycaemic effect seen with the higher dopamine dose. Somatostatin alone induced a progressive rise in circulating non-esterified fatty acid and 3-hydroxybutyrate levels reflecting insulin deficiency. This rise in NEFA and 3-hydroxybutyrate was increased by dopamine particularly at the higher dosage (plasma NEFA; somatostatin alone, 1.08 +/- 0.13 mmol/l; somatostatin plus dopamine 3 micrograms/kg/min, 1.44 +/- 0.17 mmol/l at 120 min, p less than 0.01: blood 3-hydroxybutyrate; somatostatin alone, 0.32 +/- 0.04 mmol/l; somatostatin plus dopamine 3 micrograms/kg/min, 0.56 +/- 0.12 mmol/l at 120 min, p less than 0.05). Thus: 1) dopamine at pharmacological dosage has minor effects when other endocrine mechanisms are intact, 2) it enhances lipolysis and ketogenesis during somatostatin-induced insulin deficiency; 3) the hyperglycaemia effect of the higher dopamine dose is probably mediated through stimulated glucagon secretion.
mesh_terms: D020155:3-Hydroxybutyric Acid; D000328:Adult; D000409:Alanine / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002395:Catecholamines / Q000097:blood; D004298:Dopamine / Q000494:pharmacology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005934:Glucagon / Q000097:blood; D005990:Glycerol / Q000097:blood; D013006:Growth Hormone / Q000097:blood; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006885:Hydroxybutyrates / Q000097:blood; D007328:Insulin / Q000097:blood; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D008660:Metabolism / Q000187:drug effects*; D011773:Pyruvates / Q000097:blood; D019289:Pyruvic Acid; D013004:Somatostatin / Q000494:pharmacology
chemical_list: D001786:Blood Glucose; D002395:Catecholamines; D005230:Fatty Acids, Nonesterified; D006885:Hydroxybutyrates; D007328:Insulin; D007773:Lactates; D011773:Pyruvates; D019344:Lactic Acid; D013004:Somatostatin; D019289:Pyruvic Acid; D013006:Growth Hormone; D005934:Glucagon; D000409:Alanine; D005990:Glycerol; D020155:3-Hydroxybutyric Acid; D004298:Dopamine