Stimulation of AIDS lymphocytes with calcium ionophore (A23187) and phorbol ester (PMA): Studies of cytoplasmic free Ca, IL-2 receptor expression, IL-2 production and proliferation

1989 ◽  
Vol 119 (1) ◽  
pp. 14-21 ◽  
Author(s):  
Bo Hofmann ◽  
Jarl Moller ◽  
Erik Langhoff ◽  
Klaus Damgård Jakobsen ◽  
Niels Odum ◽  
...  
1995 ◽  
Vol 14 (2) ◽  
pp. 171-177 ◽  
Author(s):  
S G Beech ◽  
S W Walker ◽  
J R Arthur ◽  
D Lee ◽  
G J Beckett

ABSTRACT The effects of TSH and the activation of the cyclic AMP (cAMP) and Ca2+-phosphatidylinositol (Ca2+-PI) cascades on the activity and expression of the selenoenzyme thyroidal type-I iodothyronine deiodinase (ID-I) have been studied using human thyrocytes grown in primary culture. Stimulation of ID-I activity and expression was obtained with TSH and an analogue of cAMP, 8-bromo-cAMP. In the presence or absence of TSH, the addition of the phorbol ester, phorbol 12-myristate 13-acetate (PMA) together with the calcium ionophore A23187, caused a decrease in ID-I activity; a decrease in ID-I expression was also observed as assessed by cell labelling with [75 Se]selenite. PMA alone had no effect on ID-I activity in the presence or absence of TSH. A23187 alone produced a small but significant reduction in ID-I activity, but only in TSH-stimulated cells. These data provide evidence that the expression of thyroidal ID-I is negatively regulated by the Ca2+-PI cascade, and positively regulated by the cAMP cascade.


2005 ◽  
Vol 27 (3) ◽  
pp. 483-490 ◽  
Author(s):  
Ana-Maria Bamberger ◽  
Juliane Briese ◽  
Julica Götze ◽  
Insa Erdmann ◽  
Heinrich M. Schulte ◽  
...  

1989 ◽  
Vol 30 (5) ◽  
pp. 583-586 ◽  
Author(s):  
A. BERTOTTO ◽  
S. CRUPI ◽  
C. ARCANGELI ◽  
R. GERLI ◽  
F. SCALISE ◽  
...  

1983 ◽  
Vol 210 (3) ◽  
pp. 885-891 ◽  
Author(s):  
S M Felber ◽  
M D Brand

1. We have monitored the plasma-membrane potential of lymphocytes by measuring the accumulation of the lipophilic cation methyltriphenylphosphonium (TPMP+) in the presence of the uncoupler carbonyl cyanide p-trifluoromethoxyphenylhydrazone (FCCP). 2. The mitogen concanavalin A causes a decrease in TPMP+ accumulation by pig lymphocytes corresponding to a 3 mV depolarization with 2 1/2 min. Concanavalin A does not alter 86Rb+ uptake in the first 30 min. 3. In contrast concanavalin A increased TPMP+ accumulation and the rate of Rb+ uptake in mouse thymocytes. This is consistent with a previous proposal that the mitogen induces a hyperpolarization of mouse thymocytes as a result of stimulation of a Ca2+-dependent K+ channel. 4. Studies with the calcium ionophore A23187 and quinine (an inhibitor of the Ca2+-dependent K+ channel) suggest that the channel is partially closed in mouse resting thymocytes but is almost fully active in pig resting cells. Thus concanavalin A hyperpolarizes mouse thymocytes by activating the Ca2+-dependent K+ channel but cannot do so in pig lymphocytes because the channel is already maximally activated. 5. The 3mV depolarization of pig cells cannot be explained by a decrease in electrogenic K+ permeability.


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