Detection from adrenal chromaffin cells

Detection of catecholamines from adrenal chromaffin cells... 

Vertebrates also show expression of AADC in both neural and non-neural tissues. AADC has been purified from kidney (Christenson et al., 1972), liver (Ando-Yamamoto et al., 1987), adrenal medulla (Albert et al., 1987), and pheochromocytoma (Coge et al., 1989 Ichinose et al., 1989). In the adrenal medulla dopamine is further processed into epinephrine and norepinephrine, which are released from the chromaffin cells during stress to increase heart rate and blood pressure. There are no detectable monoamines in the liver and kidney, and the function of AADC in these tissues is unknown. AADC activity has also been... 

Permeabilized secretory cells are widely used to study the final events during secretion by exocytosis. Convenient cellular models are bovine adrenal chromaffin cells in short term culture and the rat pheochromocytoma cell line PC 12. Both cell types take up labeled catecholamines and store them in secretory vesicles, from which they can be released upon stimulation. The released catecholamines can be detected in the supernatant. After permeabilization of the plasma membrane, release of catecholamines can be triggered by micromolar concentrations of Ca. ... 

The bovine adrenal chromaffin cells used by Wightman et al. typically release roughly 5 attomoles of detectable epinephrine and norepinephrine. Efforts have been made to detect smaller numbers of molecules released via exocytosis to the point where it has been reported that the release of 4700 and 6000 molecules can be detected per event from release of a small portion of transmitter in a vesicle (28, 29). 

Figure 14 Experiments with a carbon fiber electrode at a single adrenal chromaffin cell exposed to 50 pM histamine for 5 s (indicated by the long bar). A 3 s exposure to a solution containing 100 nM Ca + and 50 pM epinephrine was used to postcalibrate the microsensor (shown by the short bar). In panel A, release from a single cell was evoked by histamine exposure and resulted in the amperometric spikes due to catecholamine oxidation (lower panel). At the same time, Ca release was detected. In panel B, neither catecholamine nor Ca - release was detected from a single cell after histamine exposure. I is the fluorescence intensity. Data were obtained using a 5pm carbon fiber electrode held at 0.65 V vs. SSCE. (Reproduced from Anal. Client, with permission [45].)...

Silver is cleared from the system via the liver (Furchner et al. 1968 Scott and Hamilton 1950). Deposition of uncleared silver can occur along the renal glomerular basement membrane (Creasey and Moffat 1973 Danscher 1981 Ham and Tange 1972 Moffat and Creasey 1972) and mesangium (Day et al. 1976), and in the Kupffer cells and the sinusoid endothelium cells of the liver (Danscher 1981). Silver has also been detected intra- and extracellularly in the skin and mucosa of the tongue, in the chromaffin cells, cells of the zona glomerulosa, and zona fasciculata of the adrenal glands, and in the exocrine and endocrine sections of the pancreas (Danscher 1981). 

Pitta Bauermann et al. have applied constant distance shear force-controlled SECM to elec-trochemically image fibroblasts and adrenal chromaffin ceUs. In the case of the catecholamine-releasing chromaffin cells, the authors succeeded in amperometrically detecting the release of neurotransmitters from a single secretory vesicle, following chemical stimulation. 

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