Differences in Proliferation of Primary Cultures of Vascular Smooth Muscle Cells Taken from Male and Female Rats

1980 ◽  
Vol 17 (2) ◽  
pp. 110-116 ◽  
Author(s):  
P. Travo ◽  
G. Barrett ◽  
G. Burnstock
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Primary Cultures ◽  
Muscle Cells ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats

Endothelin-induced calcium responses in human vascular smooth muscle cells

1992 ◽  
Vol 262 (1) ◽  
pp. C148-C155 ◽  
Author(s):  
J. P. Gardner ◽  
G. Tokudome ◽  
H. Tomonari ◽  
E. Maher ◽  
D. Hollander ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Primary Cultures ◽  
Muscle Cells ◽  
Maximal Effect ◽  
Ca Channels ◽  
Single Class ◽  
Cytosolic Ph

The effects of endothelin-1 (ET) on the cytosolic free Ca (Cai) and cytosolic pH (pHi) were examined in primary cultures of human umbilical artery (HUA) vascular smooth muscle cells (VSMCs), respectively, loaded with fura-2 and 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. In 1 mM Ca, ET produced a dose-dependent, biphasic increase in the signal with a maximal effect at 400 nM ET. At this concentration, ET produced a Cai transient (mean +/- SE; a rise from basal Cai of 86 +/- 16 to 216 +/- 33 nM) that lasted for approximately 50-60 s. The Cai transient was followed by a slow but sustained increase in Cai. Both ET-induced Cai transient and posttransient Cai were attenuated in Ca deficient medium or by verapamil and nicardipine. In contrast to ET, thrombin elicited only a monophasic Cai response in HUA VSMCs. This response was also partially sensitive to Ca removal or verapamil. KCl (45 mM) depolarization did not elicit a Cai response. However, the presence of voltage sensitive Ca channels in HUA VSMCs was demonstrated by enhanced Mn uptake in cells depolarized with KCl. Both ET and thrombin treatment did not alter pHi. HUA VSMCs demonstrated a single class of ET receptors (approximately 13,000 sites/cell) with an equilibrium dissociation constant of 0.34 nM. Nicardipine did not alter ET binding. These observations suggest a dual effect of ET on the Cai profile in HUA VSMCs that is mediated by Ca mobilization and Ca entry through Ca channels. The Ca entry could include influx through receptor-operated Ca channels, voltage-sensitive Ca channels, or both, but without a direct interaction between ET and these channels.

ANF elicits phosphorylation of the cGMP phosphodiesterase in vascular smooth muscle cells

1998 ◽  
Vol 274 (2) ◽  
pp. H448-H455 ◽  
Author(s):  
Todd A. Wyatt ◽  
Allen J. Naftilan ◽  
Sharron H. Francis ◽  
Jackie D. Corbin
Keyword(s):  
Smooth Muscle ◽  
Catalytic Activity ◽  
Vascular Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Vascular Smooth Muscle Cells ◽  
Primary Cultures ◽  
Muscle Cells ◽  
Intact Cells ◽  
Cyclic Monophosphate ◽  
Allosteric Sites

Guanosine 3′,5′-cyclic monophosphate (cGMP)-binding, cGMP-specific phosphodiesterase (PDE5) is abundant in vascular smooth muscle, and this enzyme is a potent substrate for cGMP-dependent protein kinase (PKG) in vitro. Binding of cGMP to the allosteric sites of PDE5 is required for this phosphorylation to occur. Vascular smooth muscle cells (VSMC) were used to determine if PDE5 is phosphorylated in intact cells when cGMP is increased. With the use of anti-PDE5 antibodies, a phosphorylated 93-kDa protein band was immunoprecipitated from early passaged primary cultures of VSMC that had been preincubated with32Pito label cellular ATP and then treated with atrial natriuretic factor (ANF). In the absence of ANF, there was no detectable incorporation of radiolabeled phosphate into this band. Phosphorylation of the 93-kDa protein was augmented by pretreating cells with 8-bromoguanosine 3′,5′-cyclic monophosphate (8-BrcGMP) to activate PKG before addition of ANF. 8-BrcGMP, which interacts poorly with the allosteric sites of PDE5, had no effect on PDE5 phosphorylation in the absence of ANF. Phosphorylation of PDE5 in response to treatment of cells with ANF was associated with a two- to fourfold increase in PDE activity in immunoprecipitates. Multiple-passaged VSMC, which are deficient in PKG but retain PDE5, demonstrated no ANF-dependent increase in phosphorylation or catalytic activity of PDE5. However, incubation of immunoprecipitated PDE5 from these cells with purified PKG, cGMP, and a phosphorylation mixture containing [γ-32P]ATP resulted in32Piincorporation into PDE5 that was correlated with increased catalytic activity. These studies are the first to demonstrate phosphorylation of PDE5 in intact cells, thus suggesting a physiological role for this enzyme in smooth muscle regulation.

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