Profiles of secreted neuropeptides and catecholamines illustrate similarities and differences in response to stimulation by distinct secretagogues

Abstract

The goal of this study was to define profiles of secreted neuropeptide and catecholamine neurotransmitters that undergo co-release from sympathoadrenal chromaffin cells upon stimulation by distinct secretagogues. Chromaffin cells of the adrenal medulla participate in the dynamic responses to stress, especially that of ‘fight and flight’, and, thus, analyses of the co-release of multiple neurotransmitters is necessary to gain knowledge of how the stress response regulates cell-cell communication among physiological systems. Results of this study demonstrated that six different secretagogues stimulated the co-release of the neuropeptides Met-enkephalin, galanin, NPY, and VIP with the catecholamines dopamine, norepinephrine, and epinephrine. Importantly, the quantitative profiles of the secreted neurotransmitters showed similarities and differences upon stimulation by the different secretagogues evaluated, composed of KCl depolarization, nicotine, carbachol, PACAP, bradykinin, and histamine. The rank-orders of the secreted profiles of the neurotransmitters were generally similar among these secretagogues, but differences in the secreted amounts of each neurotransmitter occurred with different secretagogues. Epinephrine among the catecholamines showed the highest level of secretion. (Met)enkephalin showed the largest levels of secretion compared to the other neuropeptides examined. Levels of secreted catecholamines were greater than that of the neuropeptides. These data support the hypothesis that profiles of secreted neuropeptide and catecholamine neurotransmitters show similarities and differences upon stimulation by distinct secretagogues. These results illustrate the co-release of concerted neurotransmitter profiles that participate in the stress response of the sympathoadrenal nervous system.

Simultaneous monitoring of monoamines, amino acids, nucleotides and neuropeptides by liquid chromatography-tandem mass spectrometry and its application to neurosecretion in bovine chromaffin cells

“…Another interesting result was that AD and NA levels were 1000 times higher than those found for neuropeptides, especially MENK. Likewise, Podvin and co‐workers found the same proportions in large dense core secretory vesicles of BCCs . Winkler et al found a 0.4 M catecholamine concentration in adrenal large dense‐core vesicles, in contrast to our findings in BCCs (0.95 × 10 −3 M cell −1 for AD and 0.45 × 10 −3 M cell −1 for NA) if the pertinent conversion is made from our data in µg ml −1 (5 × 10 6 cells) Figure A.…”

“…NA, AD and DA levels have also been determined using electrochemical detection, and NA, AD, DA and 5‐HT have been studied using HPLC‐MS in BCCs . Gu et al analyzed catecholamines and their metabolites in an adrenal gland sample, and Podvin et al determined the vesicular content of neuropeptides and catecholamines in BCCs by radioimmunoassay.…”

Differential Properties of Venom Peptides and Proteins in Solitary vs. Social Hunting Wasps

“…This nonapeptide acts on smooth muscles with contractions or relaxations. In the neuronal cells of vertebrates, bradykinin evokes a release of neuropeptides (galanin, neuropeptide Y, and vasoactive intestinal peptide) and catecholamines (dopamine, norepinephrine, and epinephrine) by depolarizing nerve terminals [ 25 , 103 ].…”

Whole genome expression profiling associates activation of unfolded protein response with impaired production and release of epinephrine after recurrent hypoglycemia

“…Another set of genes, encoding several neuropeptides (including PENK, NPY and galanin) which are co-released with catecholamines in neuronal activity-dependent manner ([ 44 ]), were also significantly increased in the 2RH0 group ( Table 1 , Fig 6A , S1 Table ). Our data are consistent with previously reported long lasting overexpression of several neuropeptides in response to stress (including acute hypoglycemia, [ 45 ], [ 46 ], [ 47 ]).…”