In the present investigation insulin-induced hypoglycemia was used as a powerful stimulus to rapidly release epinephrine from the adrenal medulla. Insulin injection raised epinephrine 16-fold and doubled norepinephrine plasma levels. The aim of this attempt was to induce β-adrenergic receptors (β-ARs) sequestration in vivo on mononuclear leukocytes (MNLs). The number of total and surface β-ARs was significantly increased 30 minutes after insulin administration, with only partial recovery at 90 minutes. No detectable receptor sequestration was observed: surface receptors were about 90% of total receptors in all the conditions examined. Isoproterenol- stimulated cyclic adenosine monophosphate (cAMP) accumulation was also increased after 30 minutes (+66%) and 90 minutes (+65%) of insulin injection. Basal and forskolin-stimulated intracellular cAMP values were unchanged. We conclude that, even after a strong release of catecholamines, β-AR redistribution cannot be demonstrated on MNLs.
|Number of pages||5|
|Journal||The Journal of Laboratory and Clinical Medicine|
|Publication status||Published - 1992|
ASJC Scopus subject areas
- Pathology and Forensic Medicine