Author/Editor		Chowdhury-Haque, Helena; Popoff, Michel R; Zorec, Robert
Title		Actin cytoskeleton depolymerization with Clostridium spiroforme toxin enhances the secretory activity of rat melanotrophs
Type		članek
Source		J Physiol
Vol. and No.		Letnik 521, št. 2
Publication year		1999
Volume		str. 389-95
Language		eng
Abstract		1. We measured membrane capacitance (Cm) in cultured rat melanothrops pretreated with Clostridium spiroforme toxin (CST), which spacifically depymerises cartical filamentous actin (F-actin). Phalloidin staining confirmed that CST treatment depolymerised the F-actin. 2. In controll cells, cytosol dialysis with 1 microM Ca(i)2+ incrreased Cm by 23+-4% (n=11) relative to the resting Cm 400 s after the start of patch rupture. In CST-treated cells the increase in Cm was 32+-5% (n=15), not significantly different from controls. The rate of Cm increase was affected transiently by CST treatmentr, peaking at 1 min after patch rupture. The maximal rate of cm increase was 4.27 +- 0.85 fFs-1 (n=12; measured 200 s after the start of patch rupture) in controls and 8.0 +- 1.35 fFs-1 (n=23; measured 75 s after th estart of patch rupture) in CST-treated cells (p<0.01). 3. In control cells cytosol dialysis with 0 microM Ca(i)2+ decreased Cm by 9+-3% (n=7), in CST treated cells Cm increased by 11+-3% (n=7) relative to resting Cm 400 s after the start of cytosol dialysis. The rate of change in Cm remained constant (controls: -1 to -2 fFs-1; CST treatment: 1-2 fFs-1). (Abstract truncated at 2000 characters.)
Descriptors		PITUITARY GLAND CLOSTRIDIUM BACTERIAL TOXINS CYTOSKELETON ACTINS RATS, WISTAR PATCH-CLAMP TECHNIQUES CYTOSOL CELLS, CULTURED MICROSCOPY, FLUORESCENCE TIME FACTORS