Ultrastructural radioautography of the incorporation of tritiated leucine by the rat adrenal medulla in vivo

1978 ◽  
Vol 193 (2) ◽  
Author(s):  
Sarita Benchimol ◽  
Marc Cantin
2004 ◽  
Vol 44 (7) ◽  
pp. 497-503 ◽  
Author(s):  
Tsuyoshi Akiyama ◽  
Toji Yamazaki ◽  
Hidezo Mori ◽  
Kenji Sunagawa

1995 ◽  
Vol 310 (1) ◽  
pp. 331-336 ◽  
Author(s):  
R Kirchmair ◽  
B Leitner ◽  
R Fischer-Colbrie ◽  
J Marksteiner ◽  
R Hogue-Angeletti ◽  
...  

We have established a radioimmunoassay for GE-25, a peptide present in the C-terminal end of the primary amino acid sequence of chromogranin A where it is flanked by typical proteolytic cleavage sites. Gel-filtration HPLC was used to characterize the molecular sizes of the immunoreactive molecules. The antiserum recognized not only the free peptide but also larger precursors including the proprotein chromogranin A. The tissues with the highest levels of GE-25 immunoreactivity were in decreasing order: the adrenal medulla, the three lobes of the pituitary gland, intestinal mucosa, pancreas and various brain regions. In adrenal medulla and parathyroid gland most of the immunoreactivity was found to be present as intact chromogranin A and some intermediate-sized peptides, without significant amounts of the free peptide. In anterior pituitary, and even more so in intestine, a shift to smaller peptides was seen. In the posterior and intermediate pituitary and in pancreas the predominant immunoreactive material was apparently represented by the free peptide GE-25. In reverse-phase chromatography this peptide eluted exactly like the synthetic standard, which allows a tentative identification as GE-25. In brain tissue the processing of chromogranin A was intermediate, with significant amounts of immunoreactivity corresponding to GE-25 as well as precursor proteins being present. We suggest that in those organs (endocrine pancreas, intermediate and posterior pituitary) where the major hormones are proteolytically processed there is also a concomitant proteolysis of further susceptible peptides. Since GE-25 is apparently formed in vivo and is well conserved between species it seems a good candidate for having specific physiological functions.


1981 ◽  
Vol 20 (7) ◽  
pp. 639-645 ◽  
Author(s):  
S. Govoni ◽  
I. Hanbauer ◽  
T.D. Hexum ◽  
H.-Y.T. Yang ◽  
G.D. Kelly ◽  
...  

2010 ◽  
Vol 56 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Tsuyoshi Akiyama ◽  
Toji Yamazaki ◽  
Toru Kawada ◽  
Shuji Shimizu ◽  
Masaru Sugimachi ◽  
...  

2016 ◽  
Vol 230 (3) ◽  
pp. 309-323 ◽  
Author(s):  
Sushil K Mahata ◽  
Hong Zheng ◽  
Sumana Mahata ◽  
Xuefei Liu ◽  
Kaushik P Patel

One of the key mechanisms involved in sympathoexcitation in chronic heart failure (HF) is the activation of the adrenal glands. Impact of the elevated catecholamines on the hemodynamic parameters has been previously demonstrated. However, studies linking the structural effects of such overactivation with secretory performance and cell metabolism in the adrenomedullary chromaffin cells in vivo have not been previously reported. In this study, HF was induced in male Sprague-Dawley rats by ligation of the left coronary artery. Five weeks after surgery, cardiac function was assessed by ventricular hemodynamics. HF rats showed increased adrenal weight and adrenal catecholamine levels (norepinephrine, epinephrine and dopamine) compared with sham-operated rats. Rats with HF demonstrated increased small synaptic and dense core vesicle in splanchnic–adrenal synapses indicating trans-synaptic activation of catecholamine biosynthetic enzymes, increased endoplasmic reticulum and Golgi lumen width to meet the demand of increased catecholamine synthesis and release, and more mitochondria with dilated cristae and glycogen to accommodate for the increased energy demand for the increased biogenesis and exocytosis of catecholamines from the adrenal medulla. These findings suggest that increased trans-synaptic activation of the chromaffin cells within the adrenal medulla may lead to increased catecholamines in the circulation which in turn contributes to the enhanced neurohumoral drive, providing a unique mechanistic insight for enhanced catecholamine levels in plasma commonly observed in chronic HF condition.


2013 ◽  
Vol 177 (2) ◽  
pp. 123-128 ◽  
Author(s):  
Fumiaki Komaki ◽  
Tsuyoshi Akiyama ◽  
Toji Yamazaki ◽  
Hirotoshi Kitagawa ◽  
Syuichi Nosaka ◽  
...  

1974 ◽  
Vol 286 (3) ◽  
pp. 227-238 ◽  
Author(s):  
Pierre Laduron ◽  
Paul Van Gompel ◽  
Josée Leysen
Keyword(s):  

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