CHANGES IN CYCLIC NUCLEOTIDES OF RAT THYROID BY CHRONIC ADMINISTRATION OF LATS AND TSH

1978 ◽  
Vol 88 (4) ◽  
pp. 713-720 ◽  
Author(s):  
Yukio Ochi ◽  
Shiro Hosoda ◽  
Takashi Hachiya ◽  
Yoshihiro Kajita ◽  
Manabu Yoshimura ◽  
...  

ABSTRACT The effects of LATS and TSH on the cyclic nucleotide content and enzymatic activity in rat thyroid was observed during the continuous administration of LATS or TSH for 6 days. Serum T4 and T3 levels were increased significantly compared with the saline controls. The cyclic nucleotide (cAMP and cGMP) levels and enzyme activities per wet weight of tissue were determined. The thyroid weight in both the LATS and TSH groups increased approximately two-fold, but cAMP and cGMP content per wet weight did not significantly change. Neither cyclic nucleotide showed any significant change in plasma. The cAMP-PDE activity in the thyroid significantly increased in both the LATS and TSH groups, but the cGMP-PDE activity was unchanged. Neither was cyclic nucleotide-PDE activity changed in the plasma. The ATPase activity in the thyroid increased markedly in both the LATS and TSH groups, while 5′-nucleotidase activity did not change. These data suggest that LATS and TSH appear to have a stimulatory effect on the metabolism of cAMP, but do not affect the metabolism of cGMP.

1981 ◽  
Vol 98 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Yukio Ochi ◽  
Shiro Hosoda ◽  
Takashi Hachiya ◽  
Manabu Yoshimura ◽  
Tadayoshi Miyazaki ◽  
...  

Abstract. It has recently been suggested that cyclic CMP (cCMP) has a physiological role in cell function. In this study, we examined the content of cCMP, cAMP & cGMP and each hydrolyzing enzyme (phosphodiesterase, (PDE)) in rat thyroid during administration of LATS and TSH for 7 days (Exp. 1), and also in the thyroid of rats given methylthiouracil (MTU) for 4 months (Exp. 2). Each cyclic nucleotide was determined by RIA, and PDE activity was determined according to Kuo's method. Exp. 1: the wet weight of thyroid in the LATS and TSH group increased 3 and 2 times respectively, from the control. Both the LATS and TSH groups showed increased plasma T4 and T3 levels. In both groups the cAMP content per wet weight of thyroid was increased slightly, but cGMP content did not change. In contrast, the cCMP content decreased markedly. Both the LATS and TSH groups showed an increase of cAMP-PDE activity in the thyroid, and no change of cGMP-PDE, while cCMP-PDE decreased markedly. In all groups levels of these 3 cyclic nucleotides and PDE activities in plasma were unaffected. Exp. 2: in the MTU group the thyroid weight increased 4.5 times over the control, and plasma T4 and T3 levels were extremely low. The cAMP content in whole thyroid gland and also per mg wet weight was increased markedly, but cGMP content did not change. cCMP content decreased significantly. The plasma cAMP level increased slightly, but the plasma cGMP and cCMP levels did not change. The increase of cAMP content and cAMP-PDE activity, and conversely the decrease of cCMP content and cCMP-PDE in the thyroid by LATS and TSH stimulation, suggest that cCMP may play a physiologically important role within the cells, similar to cAMP in the mechanism of hormone action.


2012 ◽  
Vol 108 (11) ◽  
pp. 955-962 ◽  
Author(s):  
Alessandra Borgognone ◽  
Fabio Pulcinelli

SummaryCyclic nucleotide-dependent inhibition of platelets represents the most important physiological way to limit thrombus formation. cAMP and cGMP increase in platelets as a consequence of prostacyclin and nitric oxide production by endothelial cells and act through PKA and PKG, respectively. The cytosolic concentration of cyclic nucleotides in platelets is regulated by AC- and GC-dependent synthesis and PDE-dependent degradation. In some cells cyclic nucleotides are eliminated also through MRP4/5/8-dependent efflux. As only MRP4 is expressed in platelets, at high levels in dense granules, we determined its role in the elimination of cyclic nucleotides from platelet cytosol. We studied the effects of MRP4 inhibition on cAMP/cGMP effects in platelets. Cyclic nucleotide inhibitory effects triggered by cAMP and cGMP-elevating agents on platelet aggregation are strongly enhanced by MRP4 inhibition and so is cyclic nucleotide-dependent phosphorylation of the common substrate VASP. MRP4 inhibition decreases cAMP concentration in platelet granules and both cAMP and cGMP compete with an established substrate of MRP4 (fluo-cAMP) for entrance in granules. Here we provide the first evidence of the transport of cyclic nucleotides mediated by MRP4 as part of their physiological mechanism of elimination in human platelets, which might represent a novel target to increase cyclic nucleotide-dependent inhibition.


1981 ◽  
Vol 59 (7) ◽  
pp. 489-493 ◽  
Author(s):  
Selma Zimmerman ◽  
Arthur M. Zimmerman ◽  
Helen Laurence

Cyclic nucleotide levels were determined in division-synchronized Tetrahymena and the effect of Δ9-tetrahydrocannabinol (THC) on the cyclic nucleotide levels was studied. In non-drug-treated division-synchronized cells, there was no statistically significant variation in the level of cAMP and cGMP during the G2 period, preceding the first division. During the free running cell cycle (the interval of time between the first and second synchronous division) the twofold increase in the level of cAMP was statistically significant; however the variation in the level of cGMP was not statistically significant.THC caused a lowering of cAMP and cGMP levels throughout the 4-h experimental treatment. The suppression of cAMP and cGMP levels altered the cyclic nucleotide pattern of the cell cycle. The cAMP pattern was changed particularly in the G2 period preceding the first synchronous division, and immediately after division during the free running cell cycle. THC treatment caused division delays of approximately 8–15 min in the onset of the first and second synchronous division. However, the duration of the free running cell cycle (110–120 min) was unchanged. The suppression of cyclic nucleotide levels resulting from THC treatment is discussed in relation to delays in the division schedule.Nous avons déterminé le taux des nucléotides cycliques chez Tetrahymena se divisant de façon synchrone et nous avons étudié l'effet du Δ9-tétrahydrocannabinol (THC) sur le taux de ces nucléotides cycliques. Dans les cellules non traitées, se divisant de façon synchrone, il n'existe aucune variation statistiquement significative dans les teneurs du cAMP et du cGMP durant la période G2 précédant la première division. Durant le cycle cellulaire sans division (l'intervalle de temps entre la première et la seconde division synchrone), la teneur du cAMP augmente de deux fois, une augmentation statistiquement significative; cependant, la variation du taux du cGMP n'est pas statistiquement significative.


2020 ◽  
Vol 21 (13) ◽  
pp. 1371-1384 ◽  
Author(s):  
Vivek K. Sharma ◽  
Thakur G. Singh ◽  
Shareen Singh

Defects in brain functions associated with aging and neurodegenerative diseases benefit insignificantly from existing options, suggesting that there is a lack of understanding of pathological mechanisms. Alzheimer’s disease (AD) is such a nearly untreatable, allied to age neurological deterioration for which only the symptomatic cure is available and the agents able to mould progression of the disease, is still far away. The altered expression of phosphodiesterases (PDE) and deregulated cyclic nucleotide signaling in AD has provoked a new thought of targeting cyclic nucleotide signaling in AD. Targeting cyclic nucleotides as an intracellular messenger seems to be a viable approach for certain biological processes in the brain and controlling substantial. Whereas, the synthesis, execution, and/or degradation of cyclic nucleotides has been closely linked to cognitive deficits. In relation to cognition, the cyclic nucleotides (cAMP and cGMP) have an imperative execution in different phases of memory, including gene transcription, neurogenesis, neuronal circuitry, synaptic plasticity and neuronal survival, etc. AD is witnessed by impairments of these basic processes underlying cognition, suggesting a crucial role of cAMP/cGMP signaling in AD populations. Phosphodiesterase inhibitors are the exclusive set of enzymes to facilitate hydrolysis and degradation of cAMP and cGMP thereby, maintains their optimum levels initiating it as an interesting target to explore. The present work reviews a neuroprotective and substantial influence of PDE inhibition on physiological status, pathological progression and neurobiological markers of AD in consonance with the intensities of cAMP and cGMP.


2009 ◽  
Vol 423 (3) ◽  
pp. 401-409 ◽  
Author(s):  
Karina Matthiesen ◽  
Jacob Nielsen

To date eleven human PDE (3′,5′-cyclic nucleotide phosphodiesterase) families have been identified. Of these, five families contain non-catalytic tandem GAF (cGMP-specific and -stimulated phosphodiesterases, Anabaenaadenylate cyclases and Escherichia coliFhlA) domains, GAFa and GAFb, in the N-terminal part of the enzyme. For PDE2A, PDE5A and PDE6 the GAF domains have been shown to bind cGMP with high affinity. For PDE2A and PDE5A this ligand binding has been shown to stimulate the catalytic activity of the enzyme. PDE10A and PDE11A are the two most recently described PDEs and it has been suggested that their GAF domains bind to cAMP and cGMP respectively. We have developed a scintillation proximity-based assay to directly measure cyclic nucleotide binding to the PDE2A, PDE10A and PDE11A GAF domains, and in the present study we demonstrate binding of cyclic nucleotides to the PDE10A and PDE11A GAF domains. We show that these non-catalytic sites bind cAMP and cGMP respectively with much higher affinity than has previously been suggested using indirect assessment of the interaction. The GAFb domain of PDE10A binds cAMP with a Kd of 48 nM and the GAFa domain of PDE11A binds cGMP with a Kd of 110 nM. The effect of cyclic nucleotides binding to the GAF domains on the enzyme activity was investigated through the use of modified cyclic nucleotides. In contrast with other GAF domain-containing PDEs, and with what has previously been predicted, ligand binding to the GAF domains of PDE10A and PDE11A does not stimulate catalytic activity.


2019 ◽  
Vol 29 (12) ◽  
pp. 5022-5036 ◽  
Author(s):  
Dahdjim B Betolngar ◽  
Élia Mota ◽  
Arne Fabritius ◽  
Jacob Nielsen ◽  
Charlotte Hougaard ◽  
...  

Abstract The calcium-regulated phosphodiesterase 1 (PDE1) family is highly expressed in the brain, but its functional role in neurones is poorly understood. Using the selective PDE1 inhibitor Lu AF64196 and biosensors for cyclic nucleotides including a novel biosensor for cGMP, we analyzed the effect of PDE1 on cAMP and cGMP in individual neurones in brain slices from male newborn mice. Release of caged NMDA triggered a transient increase of intracellular calcium, which was associated with a decrease in cAMP and cGMP in medium spiny neurones in the striatum. Lu AF64196 alone did not increase neuronal cyclic nucleotide levels, but blocked the NMDA-induced reduction in cyclic nucleotides indicating that this was mediated by calcium-activated PDE1. Similar effects were observed in the prefrontal cortex and the hippocampus. Upon corelease of dopamine and NMDA, PDE1 was shown to down-regulate the D1-receptor mediated increase in cAMP. PDE1 inhibition increased long-term potentiation in rat ventral striatum, showing that PDE1 is implicated in the regulation of synaptic plasticity. Overall, our results show that PDE1 reduces cyclic nucleotide signaling in the context of glutamate and dopamine coincidence. This effect could have a therapeutic value for treating brain disorders related to dysfunctions in dopamine neuromodulation.


2007 ◽  
Vol 53 (6) ◽  
pp. 1053-1060 ◽  
Author(s):  
Isabella Russo ◽  
Paola Del Mese ◽  
Gabriella Doronzo ◽  
Alessandro De Salve ◽  
Mariantonietta Secchi ◽  
...  

Abstract Background: Impairment of platelet response to antiaggregatory agents is seen in individuals with central obesity and may play a role in the increased cardiovascular risk associated with obesity. In this study we evaluated whether this impairment involves the antiaggregatory pathways regulated by cAMP and cGMP. Methods: We obtained platelet-rich plasma from 12 obese individuals and 12 controls. We investigated the effects of the cyclic nucleotide analogs 8-pCPT-cAMP (10–500 μmol/L) and 8-pCPT-cGMP (10–500 μmol/L) on ADP-induced platelet aggregation as assessed by decreased light scattering. We assessed the activation of cAMP- and cGMP-dependent protein kinases by measuring phosphorylation of the vasodilator-stimulated phosphoprotein (VASP) at Ser157 and Ser239. Results: The antiaggregatory effect of both cyclic nucleotide analogs was impaired in obese individuals compared to controls, with mean (SE) half-maximal inhibitory concentrations (IC50) (after 20-min incubation) of 123 (33) μmol/L vs 5 (1) μmol/L, respectively, for 8-pCPT-cAMP (P <0.01) and of 172 (43) μmol/L vs 17 (8) μmol/L, respectively, for 8-pCPT-cGMP (P <0.01). The Homeostasis Model Assessment Index of Insulin Resistance was independently correlated with cyclic nucleotide analog IC50. In obese individuals, VASP phosphorylation at Ser157 and Ser239 in response to cyclic nucleotides was significantly lower than in controls. Conclusions: In central obesity the reduced ability of cyclic nucleotides to inhibit platelet aggregation is associated with reduced activation of their specific kinases. Because cyclic nucleotides help regulate platelet antiaggregation, alteration of this ability is consistent with platelet hyperactivity in obesity.


2011 ◽  
Vol 11 (S1) ◽  
Author(s):  
Katharina Werner ◽  
Frank Schwede ◽  
Hans-Gottfried Genieser ◽  
Jörg Geiger ◽  
Elke Butt

1994 ◽  
Vol 266 (4) ◽  
pp. H1494-H1501 ◽  
Author(s):  
H. Parfenova ◽  
M. Shibata ◽  
S. Zuckerman ◽  
C. W. Leffler

The role of cyclic nucleotides and prostanoids in cerebrovascular reactivity to increased carbon dioxide was investigated in anesthetized and artificially ventilated newborn pigs equipped with closed cranial windows. Pial arteriolar diameter was measured, and cortical periarachnoid cerebrospinal fluid (CSF) was collected from beneath the cranial window for determination of adenosine 3',5'-cyclic monophosphate (cAMP), guanosine 3',5'-cyclic monophosphate (cGMP), and prostanoids. Progressively increasing arterial PCO2 (PaCO2) from normocapnia (33 +/- 1 mmHg) to hypercapnia (final PaCO2, 83 +/- 2 mmHg) resulted in dose-dependent pial arteriolar dilation and concomitant increases in cAMP, cGMP, and 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha) in cortical CSF. N omega-methyl-L-arginine, N omega-nitro-L-arginine, N omega-nitro-L-arginine methyl ester, methylene blue, and LY 83583 did not inhibit cerebral vasodilation or the increases in cortical cAMP/cGMP induced by hypercapnia. Indomethacin abolished the vasodilatory response to hypercapnia and attenuated the hypercapnia-induced increases in cAMP and cGMP. Prostacyclin analogues increased both cAMP and cGMP levels in cortical CSF and induced pial arteriolar dilation (iloprost > carbaprostacyclin). The present data suggest that in newborn pigs cyclic nucleotides are involved in cerebral vasodilation in response to hypercapnia via a prostanoid-dependent mechanism.


1985 ◽  
Vol 248 (5) ◽  
pp. H745-H749 ◽  
Author(s):  
G. Bkaily ◽  
N. Sperelakis

The role of guanosine 5'-cyclic monophosphate (cGMP) in the regulation of the ionic slow channels in heart muscle is less well known than that of adenosine 3,'5'-cyclic monophosphate (cAMP). The effects of intracellular injection of cAMP and cGMP in cultured chick embryonic heart (ventricular) cells by the liposome method were studied. Injection of cAMP into the cells induced spontaneous slow action potentials that could be blocked by verapamil and nifedipine. Injection of cGMP blocked on-going slow action potentials, and this effect was reversed by increasing cAMP. Thus both cAMP and cGMP are involved in the regulation of the slow calcium channels in myocardial cells, and the two cyclic nucleotides are antagonistic.


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