TY  - JOUR
A1  - Walz, Bernd
A1  - Zimmermann, Bernhard
A1  - Seidl, Siegfried
T1  - Intracellular Ca2+ concentration and latency of light-induced Ca2+ changes in photoreceptors of the honeybee drone
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Walz, Bernd
A1  - Baumann, Otto
A1  - Zimmermann, Bernhard
A1  - Ciriacy-Wantrup, E.v.
T1  - Caffeine- and ryanodine-sensitive Ca2+-induced Ca2+ release from the endo plasmatic reticulum in honeybee photoreceptors
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
A1  - Walz, Bernd
T1  - Serotonin-induced intercellular calcium waves in salivary glands of the blowfley Calliphora erythrocephala
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
T1  - Calcium store depletion activates two distinct calcium entry pathways in secretory cells of the blowfly salivary gland
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
A1  - Walz, Bernd
T1  - The mechanism mediating regenerative intercellular Ca2+ waves in the blowfly salivary gland
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Walz, Bernd
A1  - Ukhanov, Kyrill
A1  - Zimmermann, Bernhard
T1  - Actions of neomycin on electrical light responses : Ca2+ release and intracellular Ca2+ changes in photoreceptors of the honeybee drone
Y1  - 2000
SN  - 0340-7594
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
T1  - Control of insP(3)-induced Ca2+ oscillations in permeabilized blowfly salivary gland cells : contribution of mitochondria
Y1  - 2000
SN  - 0022-3751
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
T1  - Subcellular organization of agonist-evoked Ca2+ waves in the blowfly salivary gland
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Zimmermann, Bernhard
A1  - Dames, Petra
A1  - Walz, Bernd
A1  - Baumann, Otto
T1  - Distribution and serotonin-induced activation of vacuolar-type H+-ATPase in the salivary glands of the blowfly Calliphora vicina
Y1  - 2003
ER  - 
TY  - JOUR
A1  - Dames, Petra
A1  - Zimmermann, Bernhard
A1  - Schmidt, Ruth
A1  - Rein, Julia
A1  - Voss, Martin
A1  - Schewe, Bettina
A1  - Walz, Bernd
A1  - Baumann, Otto
T1  - cAMP regulates plasma membrane vacuolar-type H+-ATPase assembly and activity in blowfly salivary glands
N2  - Reversible assembly of the V0V1 holoenzyme from V-0 and V-1 subcomplexes is a widely used mechanism for regulation of vacuolar-type H+-ATPases (V-ATPases) in animal cells. in the blowfly (Calliphora vicina) salivary gland, V- ATPase is located in the apical membrane of the secretory cells and energizes the secretion of a KCl-rich saliva in response to the hormone serotonin. We have examined whether the CAMP pathway, known to be activated by serotonin, controls V-ATPase assembly and activity. Fluorescence measurements of pH changes at the luminal surface of isolated glands demonstrate that CAMP, Sp-adenosine-3',5'-cyclic monophosphorothioate, or forskolin, similar to serotonin, cause V-ATPase-dependent luminal acidification. In addition, V-ATPase-dependent ATP hydrolysis increases upon treatment with these agents. Immunofluorescence microscopy and pelleting assays have demonstrated further that V, components become translocated from the cytoplasm to the apical membrane and V-ATPase holoenzymes are assembled at the apical membrane during conditions that increase intracellular cAMP. Because these actions occur without a change in cytosolic Ca2+, our findings suggest that the cAMP pathway mediates the reversible assembly and activation of V-ATPase molecules at the apical membrane upon hormonal stimulus
Y1  - 2006
UR  - http://www.pnas.org/
U6  - https://doi.org/10.1073/pnas.0600011103
SN  - 0027-8424
ER  - 
TY  - JOUR
A1  - Rein, Julia
A1  - Zimmermann, Bernhard
A1  - Hille, Carsten
A1  - Lang, Ingo
A1  - Walz, Bernd
A1  - Baumann, Otto
T1  - Fluorescence measurements of serotonin-induced V-ATPase-dependent pH changes at the luminal surface in salivary glands of the blowfly Calliphora vicina
N2  - Secretion in blowfly salivary glands is induced by the neurohormone serotonin and powered by a vacuolar-type H+- ATPase (V-ATPase) located in the apical membrane of the secretory cells. We have established a microfluorometric method for analysing pH changes at the luminal surface of the secretory epithelial cells by using the fluorescent dye 5-N- hexadecanoyl-aminofluorescein (HAF). After injection of HAF into the lumen of the tubular salivary gland, the fatty acyl chain of the dye molecule partitions into the outer leaflet of the plasma membrane and its pH-sensitive fluorescent moiety is exposed at the cell surface. Confocal imaging has confirmed that HAF distributes over the entire apical membrane of the secretory cells and remains restricted to this membrane domain. Ratiometric analysis of HAF fluorescence demonstrates that serotonin leads to a reversible dose-dependent acidification at the luminal surface. Inhibition by concanamycin A confirms that the serotonin-induced acidification at the luminal surface is due to H+ transport across the apical membrane via V-ATPase. Measurements with pH-sensitive microelectrodes corroborate a serotonin-induced luminal acidification and demonstrate that luminal pH decreases by about 0.4 pH units at saturating serotonin concentrations. We conclude that ratiometric measurements of HAF fluorescence provide an elegant method for monitoring V-ATPase-dependent H+ transport in the blowfly salivary gland in vivo and for analysing the spatiotemporal pattern of pH changes at the luminal surface
Y1  - 2006
UR  - http://jeb.biologists.org/
U6  - https://doi.org/10.1242/Jeb.02187
SN  - 0022-0949
ER  -