Co-release of enkephalin and catecholamines from cultured adrenal chromaffin cells

Abstract

The opioid peptides Leu-enkephalin and Met-enkephalin are stored intraneuronally in the brain where they are thought to act as neurotransmitters and/or neuromodulators. Evidence for their release from nerve terminals has come from biochemical and pharmacological studies in vitro with brain tissue slices and synaptosomes. Enkephalins also exist in the peripheral nervous system in nerve cell bodies and axon terminals in the gastrointestinal tract, sympathetic ganglia and adrenal gland. In the adrenal gland, high levels of enkephalins are present both in axon terminals of the splanchnic nerve and in the adrenal medullary chromaffin cells where they are stored together with the catecholamines in the chromaffin granules. Stimulation of the adrenal gland in vivo or the perfused gland in vitro causes release of catecholamines and enkephalins into the adrenal vein. However, it is not clear whether the origin of the released enkephalins is the adrenal medullary chromaffin cells or the enkephalin-containing splanchnic nerve terminals that innervate the medulla. We now show that enkephalin and catecholamines are released together from primary cultures of bovine adrenal medullary chromaffin cells by nicotine in a Ca2+-dependent manner.

Glucocorticoids elevate the level of enkephalin‐like peptides in neuroblastoma × glioma hybrid cells

“…Agonists or antagonists for both receptors are without clearcut reproducible effects. This is in contrast to the adrenal medulla where acetylcholine causes via a nicotinic cholinergic receptor [26] a significant release of opioid peptides from the chromaffin cells [4]. This difference may be due to differences in the state of differentiation or the cholinergic receptors involved.…”

Genetically Engineered Human Mesenchymal Stem Cells Produce Met-Enkephalin at Augmented Higher Levels in Vitro

“…Although chromaffin cells are not very immunogenic and purified patients with terminal cancer (4,11,26). Adrenal medulary chromaffin cells synthesize and release several comxenogeneic chromaffin cells can minimize immunorejection, even a small number of passenger cells (i.e., fipounds, including enkephalins and catecholamines (5,23). These agents reduce pain sensitivity when injected dibroblast and endothelial cells) in the transplant preparation are highly immunogenic (2,10).…”

“…After the transfection, GFP expression was checked with a Leica fluorescent microscope. of nociception (3,5,6,15,25). Following transfection, the expression of human PPE (hPPE) and green fluorescent Gene Expression Analysis by RT-PCR protein (GFP) genes and the production of Met-enkephalin in MeSCs were examined by RT-PCR and an immuFour days after transfection, hPPE and GFP gene expressions were analyzed by RT-PCR.…”

Alternative modes of enkephalin biosynthesis regulation by reserpine and cyclic AMP in cultured chromaffin cells.

“…The bovine adrenal medulla also contains high levels of enkephalin peptides and has been used as starting material both for the purification and sequencing of preproenkephalin peptides and for cloning and sequencing complementary DNA to preproenkephalin messenger RNA (mRNAenk) (3)(4)(5)(6). In addition, primary cultures of bovine adrenomedullary cells have been used as a model system to examine enkephalin peptide co-release with catecholamines and the regulation of enkephalin biosynthesis by hormones and pharmacological agents (7)(8)(9)(10)(11)(12). In this study, we examined whether the effects of two types of pharmacological agents known to increase enkephalin peptide levels in chromaffin cells (9,10,12) could be accounted for by increased enkephalin gene transcription, which would be reflected in increased cellular mRNAenk, or if post-transcriptional events such as mRNA translation or preproenkephalin processing might be regulat- (12) was measured by radioimmunoassay, using an enkephalin antiserum (RB-4) provided by Steve Sabol (National Heart, Lung, and Blood Institute, National Institutes of Health).…”