scholarly journals Kinetics of exocytosis in adrenal chromaffin cells

1997 ◽  
Vol 8 (2) ◽  
pp. 133-140 ◽  
Author(s):  
Kevin D. Gillis ◽  
Robert H. Chow
PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e75845 ◽  
Author(s):  
Virginia García-Martínez ◽  
José Villanueva ◽  
Cristina J. Torregrosa-Hetland ◽  
Robert Bittman ◽  
Ashlee Higdon ◽  
...  

Neuron ◽  
1994 ◽  
Vol 13 (5) ◽  
pp. 1119-1129 ◽  
Author(s):  
Frank T. Horrigan ◽  
Richard J. Bookman

2012 ◽  
Vol 90 (6) ◽  
pp. 791-801 ◽  
Author(s):  
Nan Wang ◽  
Andy K. Lee ◽  
Lei Yan ◽  
Michael R. Simpson ◽  
Amy Tse ◽  
...  

Catecholamine-containing small dense core granules (SDCGs, vesicular diameter of ∼100 nm) are prominent in carotid glomus (chemosensory) cells and some neurons, but the release kinetics from individual SDCGs has not been studied in detail. In this study, we compared the amperometric signals from glomus cells with those from adrenal chromaffin cells, which also secrete catecholamine but via large dense core granules (LDCGs, vesicular diameter of ∼200–250 nm). When exocytosis was triggered by whole-cell dialysis (which raised the concentration of intracellular Ca2+ ([Ca2+]i) to ∼0.5 µmol/L), the proportion of the type of signal that represents a flickering fusion pore was 9-fold higher for glomus cells. Yet, at the same range of quantal size (Q, the total amount of catecholamine that can be released from a granule), the kinetics of every phase of the amperometric spike signals from glomus cells was faster. Our data indicate that the last phenomenon involved at least 2 mechanisms: (i) the granule matrix of glomus cells can supply a higher concentration of free catecholamine during exocytosis; (ii) a modest elevation of [Ca2+]i triggers a form of rapid “kiss-and-run” exocytosis, which is very prevalent among glomus SDCGs and leads to incomplete release of their catecholamine content (and underestimation of their Q value).


Author(s):  
Joe A. Mascorro ◽  
Robert D. Yates

Extra-adrenal chromaffin organs (abdominal paraganglia) constitute rich sources of catecholamines. It is believed that these bodies contain norepinephrine exclusively. However, the present workers recently observed epinephrine type granules in para- ganglion cells. This report investigates catecholamine containing granules in rabbit paraganglia at the ultrastructural level.New Zealand white rabbits (150-170 grams) were anesthetized with 50 mg/kg Nembutal (IP) and perfused with 3% glutaraldehyde buffered with 0.2M sodium phosphate, pH 7.3. The retroperitoneal tissue blocks were removed and placed in perfusion fluid for 4 hours. The abdominal paraganglia were dissected from the blocks, diced, washed in phosphate buffer and fixed in 1% osmic acid buffered with phosphate. In other animals, the glutaraldehyde perfused tissue blocks were immersed for 1 hour in 3% glutaraldehyde/2.5% potassium iodate buffered as before. The paraganglia were then diced, separated into two vials and washed in the buffer. A portion of this tissue received osmic acid fixation.


1997 ◽  
Vol 73 ◽  
pp. 226
Author(s):  
Kazuo Minakuchi ◽  
Hitoshi Houchi ◽  
Masanori Yoshizumi ◽  
Yasuko Ishimura ◽  
Kyoji Morita ◽  
...  

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