Forskolin perturbs cGMP as well as cAMP levels in human thyroid cells

1984 ◽  
Vol 107 (2) ◽  
pp. 225-229 ◽  
Author(s):  
Maria Luisa Brandi ◽  
Carlo M. Rotella ◽  
Andrea Lopponi ◽  
Leonard D. Kohn ◽  
Salvatore M. Aloj ◽  
...  
Keyword(s):  
Guanylate Cyclase ◽  
Cyclase Activity ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Camp Production ◽  
Thyroid Cells ◽  
Guanylate Cyclase Activity ◽  
Low Concentrations ◽  
Camp Levels ◽  
Stimulation Of

Abstract. Forskolin, at 10−11 m, stimulates guanylate cyclase activity in primary human thyroid cell cultures, but does not modify cAMP accumulation. At a 10-fold higher concentration it still stimulates guanylate cyclase activity and becomes an inhibitor of cAMP production. Above 10−9 m, forskolin stimulation of cGMP decreases, while it also becomes a stimulator of cAMP production. There is an additive effect of TSH and forskolin on cAMP production at concentrations of the diterpene which are stimulatory. Concentrations of forskolin which are inhibitory for cAMP, but stimulatory for cGMP, are inhibitory for TSH stimulation of cAMP. The addition of 8-bromo-cGMP duplicates the forskolin effect at low concentrations.

scholarly journals Methylprednisolone stimulation of guanylate cyclase activity in rat ileal mucosa

1978 ◽  
Vol 74 (5) ◽  
pp. 1062 ◽  
Author(s):  
W.G. Marnane ◽  
A.N. Charney ◽  
E.C. Boedeker ◽  
M. Donowitz
Keyword(s):  
Guanylate Cyclase ◽  
Cyclase Activity ◽  
Ileal Mucosa ◽  
Guanylate Cyclase Activity ◽  
Stimulation Of

Differential effects of interleukin 1α and 1β on cultured human and rat thyroid epithelial cells

1990 ◽  
Vol 122 (4) ◽  
pp. 520-526 ◽  
Author(s):  
Å. Krogh Rasmussen ◽  
L. Kayser ◽  
K. Bech ◽  
U. Feldt-Rasmussen ◽  
H. Perrild ◽  
...  
Keyword(s):  
Cell Line ◽  
Interleukin 1 ◽  
Cell System ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Camp Production ◽  
Thyroid Cells ◽  
Thyroid Cell Line ◽  
Interleukin 1Α ◽  
Rat Thyroid

Abstract The effects of human recombinant interleukin 1α (20 pg/1-2 μg/l) and 1β (200 pg/1-20 μg/l) on two systems of thyroid cells have been compared. The thyroglobulin and cAMP secretion and the DNA content of human thyroid cells cultured in monolayer and of continuously grown rat thyroid cells, Fischer rat thyroid cell line have been studied. The growth of the rat thyroid cell line was inhibited by interleukin 1β (20 ng/1-20 μg/l), but not by interleukin 1α. None of the cytokines changed the cAMP production of the rat thyroid cells. In contrast, both cAMP production and thyroglobulin secretion were inhibited dose-dependently by the cytokines in human thyroid cells in secondary cultures. These results caution the interpretation and extrapolation of changes induced by interleukin 1 from one cell system to the other.

Human and rat growth hormones enhance guanylate cyclase activity

1981 ◽  
Vol 240 (2) ◽  
pp. E79-E82
Author(s):  
D. L. Vesely
Keyword(s):  
Growth Hormone ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Human Growth ◽  
Growth Hormones ◽  
Cyclase Activity ◽  
Kidney Cortex ◽  
Guanylate Cyclase Activity ◽  
Rat Growth ◽  
Stimulation Of

The objective of this investigation was to determine whether physiological levels of growth hormone have part of their mechanism of action through stimulation of guanylate cyclase (EC 4.6.1.2.). Rat and human growth hormones enhanced the activity of soluble guanylate cyclase two- to fourfold in rat gracilis anticus skeletal muscle, liver, lung, heart, pancreas, and kidney cortex at a concentration of 10 nM. Dose-response relationships revealed that more than half-maximal stimulation of guanylate cyclase activity was seen at a concentration as low as 10 nM and nonstimulation of guanylate cyclase activity was seen when the concentration was decreased to 1 nM. Maximal enhancement was seen at 100 nM of growth hormone, and there was no further enhancement when the concentration was increased to the micromolar or millimolar range. Thus, the data in this investigation indicate that at concentrations at which growth hormone is known to cause its growth-promoting effects, growth hormone does cause an enhancement of the activity of the guanylate cyclase-cyclic GMP system.

A role for intracellular calcium and calmodulin in the release of triiodothyronine from human thyroid-cell monolayer cultures

1984 ◽  
Vol 4 (8) ◽  
pp. 695-702 ◽  
Author(s):  
C. A. Ollis ◽  
R. Davies ◽  
D. S. Munro ◽  
S. Tomlinson
Keyword(s):  
Intracellular Calcium ◽  
Cell Monolayer ◽  
Calcium Ionophore ◽  
Cytosolic Calcium ◽  
Human Thyroid ◽  
Free Calcium ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Calmodulin Antagonist ◽  
Low Concentrations

Human thyroid cells in monolayer responded to acute stimulation by TSH with an increase in the secretion of T3. This process appeared to be dependent on a rise in the cytosolic calcium concentration since the antagonist of intraceliular calcium mobilization, TMB-8, was found to inhibit the release of T3 in response to TSH. The importance of intracellular calcium was further shown using the agent veratridine which increases the free calcium level within cells; veratridine potentiated the stimulation of T3 secretion by TSH and itself stimulated the release of T3 to a level higher than that seen in the presence of TSH alone. The calcium ionophore A23197 produced a biphasic effect on T3 secretion from human thyroid monolayers; at low concentrations, A23187 caused a decrease in both unstimulated and TSH-stimulated T3 secretion but above a concentration of 1 μM, T3 secretion was increased. The calmodulin antagonist W7 was found to inhibit T3 release in response to TSH, indicating a role for calmodulin in mediating the effects of intracellular calcium on T3 secretion.

Cation-dependent vitamin D activation of human renal cortical guanylate cyclase

1984 ◽  
Vol 246 (1) ◽  
pp. E115-E120 ◽  
Author(s):  
D. L. Vesely ◽  
D. Juan
Keyword(s):  
Vitamin D ◽  
Guanylate Cyclase ◽  
Cellular Level ◽  
Cyclase Activity ◽  
Rat Tissues ◽  
Response Curves ◽  
Guanylate Cyclase Activity ◽  
Manganese Ion ◽  
Maximal Stimulation ◽  
Stimulation Of

The objective of this investigation was to determine whether physiological levels of vitamin D and its metabolites have part of their mechanisms of action through stimulation of guanylate cyclase (EC 4.6.1.2). These sterols enhanced both soluble and particulate guanylate cyclase activities as well as cGMP levels two- to threefold in human and rat tissues. At a concentration of 1 nM, 1,25(OH)2D3 greater than 25(OH)D3 greater than vitamin D3 greater than 24,25(OH)2D3 = 25,26(OH)2D3 = vitamin D2. Dose-response curves revealed that maximal stimulation of guanylate cyclase by these sterols was at 1 nM and that there was no augmented guanylate cyclase activity at 0.01 nM. The precursors of vitamin D, cholesterol and 7-dehydrocholesterol, had no effect on guanylate cyclase activity. The activation of guanylate cyclase activity by the vitamin D sterols required the presence of manganese ion. Calcium was not as efficient as manganese in optimizing basal or hormone-stimulated guanylate cyclase activity. Vitamin D and its metabolites failed to stimulate adenylate cyclase (EC 4.6.1.1) activity. The data in this investigation suggest that guanylate cyclase may play a role in the mechanism of action of vitamin D at the cellular level.

Angiotensin II stimulates guanylate cyclase activity in aorta, heart, and kidney

1981 ◽  
Vol 240 (4) ◽  
pp. E391-E393
Author(s):  
D. L. Vesely
Keyword(s):  
Angiotensin Ii ◽  
Mechanism Of Action ◽  
Guanylate Cyclase ◽  
Rat Aorta ◽  
Cellular Level ◽  
Cyclase Activity ◽  
Response Curves ◽  
Guanylate Cyclase Activity ◽  
Maximal Stimulation ◽  
Stimulation Of

The objective of the present investigation was to determine whether angiotensin II at physiological levels has part of its mechanism of action through stimulation of the activity of guanylate cyclase (EC 4.6.1.2), the enzyme that catalyzes the conversion of guanosine triphosphate to cyclic GMP. Angiotensin II enhanced guanylate cyclase activity three-to fivefold in rat aorta, heart, and kidney at a concentration of 1 nM. Dose-response curves revealed that near maximal stimulation of guanylate cyclase with angiotensin II was observed at a concentration as low as 10 pM. The guanylate cyclase cofactor manganese was necessary for the maximal enhancement of guanylate cyclase by angiotensin II. The data in this investigation suggest that guanylate cyclase may play a role in the mechanism of action of angiotensin II at the cellular level.

scholarly journals Methylprednisolone stimulation of guanylate cyclase activity in rat small intestinal mucosa: Possible role in electrolyte transport

1981 ◽  
Vol 81 (1) ◽  
pp. 90-100 ◽  
Author(s):  
William G. Marnane ◽  
Yuan-Heng Tai ◽  
Robert A. Decker ◽  
Edgar C. Boedeker ◽  
Alan N. Charney ◽  
...  
Keyword(s):  
Intestinal Mucosa ◽  
Guanylate Cyclase ◽  
Electrolyte Transport ◽  
Cyclase Activity ◽  
Small Intestinal Mucosa ◽  
Guanylate Cyclase Activity ◽  
Small Intestinal ◽  
Stimulation Of
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