Inhibitory Effect Of Trifluoperazine Research Articles

Inhibitory Effects of Trifluoperazine on Peripheral Proinflammatory Cytokine Expression and Hypothalamic Microglia Activation in Obese Mice Induced by Chronic Feeding With High-Fat-Diet.

Microglia and astrocytes are the glial cells of the central nervous system (CNS) to support neurodevelopment and neuronal function. Yet, their activation in association with CNS inflammation is involved in the initiation and progression of neurological disorders. Mild inflammation in the periphery and glial activation called as gliosis in the hypothalamic region, arcuate nucleus (ARC), are generally observed in obese individuals and animal models. Thus, reduction in peripheral and central inflammation is considered as a strategy to lessen the abnormality of obesity-associated metabolic indices. In this study, we reported that acute peripheral challenge by inflammagen lipopolysaccharide (LPS) upregulated the expression of hypothalamic dopamine type 2 receptor (D2R) mRNA, and chronic feeding by high-fat-diet (HFD) significantly caused increased levels of D2R in the ARC. The in vitro and in vivo studies indicated that an FDA-approved antipsychotic drug named trifluoperazine (TFP), a D2R inhibitor was able to suppress LPS-stimulated activation of microglia and effectively inhibited LPS-induced peripheral inflammation, as well as hypothalamic inflammation. Further findings showed daily peripheral administration intraperitoneally (i.p.) by TFP for 4 weeks was able to reduce the levels of plasma tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in accompany with lower levels of plasma glucose and insulin in obese mice receiving HFD for 16 weeks when compared those in obese mice without TFP treatment. In parallel, the activation of microglia and astrocytes in the ARC was also inhibited by peripheral administration by TFP. According to our results, TFP has the ability to suppress HFD-induced ARC gliosis and inflammation in the hypothalamus.

Ca2+ dependence and inhibitory effects of trifluoperazine on plasma membrane ATPase of Thermoactinomyces vulgaris.

Ca2+ enhanced the plasma membrane Ca(2+)-ATPase (PMCA) specific activities in wild-type strain 1227 and mutant strains 1278, 1286, and 1261 of Thermoactinomyces vulgaris. The Ca(2+)-ATPase specific activities showed marked increase with increasing concentrations of Ca2+ added in the form of CaCl2 in the culture medium and reached the optimum values at 0.6 mM in strains 1227, 1278, and 1286 and at 0.7 mM in strain 1261 of T. vulgaris. Trifluoperazine, a specific blocker of calmodulin, when added in vivo at concentrations of 2 microM and 8 microM along with the respective optimal concentrations of Ca2+, decreased the PMCA-specific activities to a low level in a dose-dependent manner. The results of the present investigation suggest the presence of a Ca(2+)-dependent protein activator (CaDPA) in the microenvironment constituting this enzyme; and such Ca(2+)-modulated protein has been assigned to play an important role in the enhancement of PMCA levels in this aerobic, spore-forming, thermophilic actinomycete.

Involvement of calmodulin and calmodulin-binding proteins in the differentiation of tracheary elements in Zinnia cells

Inhibitors of the action of calmodulin, such as trifluoperazine, chlorpromazine and tetracaine, prevented the differentiation of tracheary elements in isolated mesophyll cells of Zinnia elegans L. but did not prevent cell division. Differentiation was also completely inhibited by W-7, while cell division was inhibited by only 40‰. Results of pulse-treatment with trifluoperazine indicated that the inhibitory effect of trifluoperazine on differentiation was maximal immediately before the formation of secondary walls. A calmodulin-overlay method revealed the presence in Zinnia cells of calmodulin-binding proteins whose levels increased in a hormone-dependent manner during differentiation. In particular, calmodulin-binding proteins of 28 and 27 kDa appeared abruptly immediately before the formation of secondary walls. The dramatic appearance of the binding proteins required the presence of both auxin and cytokinin. Levels of calmodulin were also found to increase rapidly between 36 and 48 h of culture, prior to the formation of secondary walls. Since both auxin and cytokinin are prerequisites for the induction and progression of the differentiation of tracheary elements (Fukuda and Komamine, 1980, Plant Physiol. 65, 57–60), our results suggest that calmodulin and calmodulin-binding proteins play important roles in the progression of the differentiation of tracheary elements immediately before the formation of secondary walls.

Trifluoperazine and calmidazolium have multiple actions on the release of noradrenaline from sympathetic nerves of mouse atria.

The aim of this study was to determine whether the calmodulin inhibitors trifluoperazine (TFP) and calmidazolium (CMZ) could decrease the action-potential-evoked release of noradrenaline from mouse isolated atria incubated with [3H]-noradrenaline in support of the hypothesis that calmodulin is involved in neurotransmitter release. TFP (10 microM and 30 microM) significantly enhanced stimulation-induced (S-I) outflow of radioactivity from mouse atria but had no effect at 1.0 microM or 70 microM. TFP (70 microM) also significantly increased the spontaneous outflow of radioactivity. The facilitatory effect of TFP (10 microM) on S-I outflow of radioactivity persisted in either the presence of 3-isobutyl-1-methylxanthine (100 microM) or atropine (0.3 microM) indicating that this effect of TFP was not mediated through either inhibition of phosphodiesterases or through interference with presynaptic muscarinic receptors, respectively. In the presence of phentolamine, the facilitatory effect of TFP (10 microM) on S-I outflow was reduced but there was no effect on S-I outflow at 70 microM. However, in the presence of a combination of both phentolamine (1.0 microM) and the neuronal uptake blocker desipramine (1.0 microM) a significant inhibitory effect of TFP (70 microM) on the S-I outflow of radioactivity was observed, indicating that effects of TFP on presynaptic alpha-adrenoceptors and neuronal uptake had disguised an inhibitory effect on S-I noradrenaline release. Another inhibitor of the Ca(2+)-calmodulin complex, calmidazolium (CMZ, 10 microM) inhibited the S-I outflow of radioactivity but had no effect at 1.0 microM. However, CMZ (10 microM) also induced a concomitant increase in the spontaneous outflow of radioactivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective effect of calmodulin inhibitors against acute cyanide-induced lethality and convulsions in mice

The ED 50 value of cyanide as measured by induction of convulsions (tonic seizure) was significantly increased by 80% or 69% when trifluoperazine (TFP) or chlorpromazine (CHP), a specific calmodulin inhibitor was preinjected intracerebroventricularly (i.v.t.) at a dose of 0.09 μmol/body of mice. However, the ED 50 of cyanide was not significantly changed by the same dose of promethazine (PMZ), another calmodulin inhibitor. Since it is known that the inhibitory effect of TFP or CHP against calmodulin-dependent enzymes such as phosphodiesterase is 100–400-fold higher compared to PMZ, it is speculated that the inhibitory effect of TFP or CHP against cyanide-induced convulsions may be based on its strong inhibitory properties into calmodulin-dependent enzymes. On the other hand, the LD 50 value of cyanide was significantly increased by i.v.t. preadministration of TFP or CHP (0.045 μmol/body). Furthermore, the LD 50 value of cyanide was also significantly increased by the same dose of PMZ. These results suggest that there is no positive correlation between mortality and convulsions induced by cyanide.

Influence of trifluoperazine on the late stage of influenza virus infection in MDCK cells

We investigated the influence of the anticalmodulin drug, trifluoperazine (TFP) on influenza virus growth in MDCK cells. The inhibitory effect of TFP on virus growth was observed even when TFP was added at a late stage of infection. This inhibitory effect was concentration-dependent in the concentration range of 20–35 μM. At 35 μM, TFP caused a complete alteration in the distribution pattern of hemagglutinin (HA), concomitant with a decrease in the appearance of HA on the cell surface. After removal of the drug, the HA gradually began to show a normal distribution pattern and reappeared on the cell surface. The time course of rearrangement of HA was in accord with that of the recovery of cell supernatant infectivity. Scanning electron microscopic study revealed that the drug did not cause accumulation of the progeny viruses on the cell surface. The drug effect on the virus growth was reversed by the simultaneous presence of purified calmodulin (CaM). These data suggest that TFP acts as a reversible inhibitor of influenza virus morphogenesis, but not budding, by disturbing cellular CaM and/or CaM-dependent functions.

The effect of trifluoperazine on muscle tension and cytoplasmic Ca2+ level in guinea pig ileum.

In guinea pig ileal muscle strips, trifluoperazine (TFP) inhibited the high K+-induced contraction with an IC50 of 1.9 microM and the Ca2+-induced contraction in skinned fiber with an IC50 of 44 microM. TFP decreased the high K+-induced increase in cytoplasmic Ca2+ level at the concentration 3 microM, which did not inhibit the contraction in skinned fiber. It is suggested that the inhibitory effect of TFP on the high K+-induced contraction is mainly due to the decrease in cytoplasmic Ca2+.

The Effect of Trifluoperazine on Muscle Tension and Cytoplasmic Ca2+ Level in Guinea Pig Ileum

In guinea pig ileal muscle strips, trifluoperazine (TFP) inhibited the high K+-induced contraction with an IC50 of 1.9 μM and the Ca2+-induced contraction in skinned fiber with an IC50 of 44 μM. TFP decreased the high K+-induced increase in cytoplasmic Ca2+ level at the concentration 3 μM, which did not inhibit the contraction in skinned fiber. It is suggested that the inhibitory effect of TFP on the high K+-induced contraction is mainly due to the decrease in cytoplasmic Ca2+.

Increase by trifluoperazine in calcium sensitivity of myofibrils in a skinned fibre from frog skeletal muscle.

1. Since it has been demonstrated that trifluoperazine (TFP) increases the affinity for Ca2+ of troponin C as well as calmodulin, the effect of TFP was examined on the Ca2+-induced tension in mechanically skinned fibres isolated from frog skeletal muscle and on Ca2+-dependent ATPase activity of myofibrils from similar frog skeletal muscle. 2. Lower concentrations of TFP increased the Ca2+ sensitivity of myofibrils without a change in the maximum tension, giving rise to a less steep tension-pCa relationship. This effect was reversible although thorough washes were necessary. The drug also enhanced myofibrillar ATPase activity, not only at low Ca2+ concentrations but also at saturating high Ca2+ concentrations. The increased affinity of troponin C for Ca2+ is difficult to accept as the sole explanation for the stimulatory effect of TFP. 3. Half of the maximum stimulating effect was obtained between 10 and 30 microM-TFP, which is similar to the reported apparent inhibition constant (Ki) for calmodulin-dependent enzyme reactions. However, the stimulating effect of TFP cannot be attributed to its inhibition of calmodulin because of the finding that this effect was independent of Ca2+. Earlier published results (e.g. Klee & Vanaman, 1982) also support this conclusion. 4. Studies on myofibrillar ATPase activity suggest that the stimulating effect of TFP is not identical in its underlying action with those of caffeine and quercetin, which are also known as Ca2+-sensitizing drugs, having a similar eventual effect on tension development. 5. Higher concentrations of TFP decreased the maximum tension induced by high concentrations of Ca2+, while enhancing the tension in the presence of low concentrations of Ca2+. Analogous findings for ATPase activity were also made. TFP concentration for half the maximum depression was about 10 times higher than that for half the maximum stimulation. This suggests that different site(s) are involved in the stimulatory and inhibitory effects of TFP, although there may be some sites in common. 6. Discussion favours the stimulating effects of TFP as being caused considerably by the affected molecular interactions among myosin, actin, tropomyosin and troponin.

Trifluoperazine inhibits ovarian mitochondrial side-chain cleavage enzyme activity in the absence of calcium

In a previous report we described the inhibitory effect of trifluoperazine (TFP) on steroidogenesis in avian granulosa cells. To clarify the possible site of action of TFP we measured the cholesterol side-chain cleavage enzyme (CSCC) activity in a mitochondrial preparation of granulosa cells isolated from mature and developing ovarian follicles. Using a calcium free medium, TFP inhibited CSCC in a dose related manner with an IC 50 of 50 μM. Kinetic parameters (apparent K m and V max ) obtained in the presence of TFP are indicative of uncompetitive inhibition of CSCC. Moreover, enzyme activity increased during follicular maturation while the efficacy of TFP was similar in both young and mature follicles. Because the inhibitory effects of TFP were manifest in medium from which calcium was omitted, it is suggested that the drug acts independently of the calcium-calmodulin system to suppress CSCC activity.

P-109 - Inhibitory effects of trifluoperazine and W-7 on amylase release from rat parotid acinar cells

P-109 - Inhibitory effects of trifluoperazine and W-7 on amylase release from rat parotid acinar cells

Inhibitory Effects of Trifluoperazine and Chlorpromazine, Calmodulin Inhibitor, on Autoregulation of Renal Blood Flow

An intra-arterial infusion of a calmodulin inhibitor trifluoperazine (3 mg/min) or chlorpromazine (5 mg/min) caused obvious inhibition of autoregulation of renal blood flow in dogs. Simultaneous infusion of CaCl2 (30 mg/min) or Ca channel activator BAY K 8644 (5 μg/min) with these calmodulin inhibitors reduced renal blood flow, but could not block the inhibitory activity of calmodulin inhibitors on the autoregulation. The present experiment shows the contribution of the Ca-calmodulin system to the mechanism of autoregulation of renal blood flow.

Inhibitory effects of trifluoperazine and chlorpromazine, calmodulin inhibitor, on autoregulation of renal blood flow.

An intra-arterial infusion of a calmodulin inhibitor trifluoperazine (3 mg/min) or chlorpromazine (5 mg/min) caused obvious inhibition of autoregulation of renal blood flow in dogs. Simultaneous infusion of CaCl2 (30 mg/min) or Ca channel activator BAY K 8644 (5 micrograms/min) with these calmodulin inhibitors reduced renal blood flow, but could not block the inhibitory activity of calmodulin inhibitors on the autoregulation. The present experiment shows the contribution of the Ca-calmodulin system to the mechanism of autoregulation of renal blood flow.

Trifluoperazine inhibits progesterone and cyclic AMP production in granulosa cells of the hen ( Gallus domesticus)

Unstimulated (basal) as well as luteinizing hormone (LH)-promoted progesterone production in collagenase-dispersed hen granulosa cells was inhibited in a dose-related manner by two phenothiazines, trifluoperazine (TFP) and chlorpromazine (CP), both of which are known calmodulin antagonists. Using TFP, the more potent antagonist of the two, it was found that LH-stimulated cyclic AMP production was also suppressed. Moreover, TFP attenuated the steroidogenic effects of both 8-bromo-cyclic AMP and isobutylmethylxanthine but had no effect on the conversion of pregnenolone to progesterone. The inhibitory effects of TFP on steroidogenesis were reversible. It is concluded that phenothiazines inhibit steroidogenesis in ovarian granulosa cells by acting at multiple sites both proximal and distal to cyclic AMP generation without influencing the enzyme complex responsible for the conversion of pregnenolone to progesterone. The results are discussed in relation to calmodulin- and non-calmodulin-mediated actions of phenothiazines.

Possible role of calmodulin in the control of histamine release from human basophil leukocytes

We investigated the possible role of calmodulin (CaM) in the control of histamine release from human basophil leukocytes using several CaM antagonists. Trifluoperazine (TFP)(10 −6 − 2 × 10 −5 M), pimozide (10 −6 − 1.5 × 10 −5 M), chlorpromazine (CPZ) (10 −5 − 10 −4 M) and promethazine (PMZ) (2 × 10 −5 − 10 −4 M) inhibited in vitro histamine secretion from human basophils induced by several immunological (antigen, anti-IgE, and formyl-L-methionyl-L-leucyl-L-phenylalanine: f-met peptide) and nonimmunological (Ca 2+ ionophore A23187 and the tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate: TPA) stimuli. Trifluoperazine sulfoxide (TFP-S) and chlorpromazine sulfoxide (CPZ-S), which have very low affinity to CaM, had practically no inhibitory effect on histamine release from human basophils. The inhibitory effect of TFP could be made irreversible by irradiating the cells with UV light. A sulfonamide derivative, the compound N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide hydrochloride (W-7) (2.5 × 10 −5 − 2 × 10 −4 M), which selectively binds to CaM, inhibited the release of histamine from basophils. In contrast, the chloride deficient analogue, W-5, which interacts only weakly with CaM, had practically no inhibiting effect. The IC 50 for enzyme release by a series of eight CaM antagonists was closely correlated (r = 0.91; p < 0.001) with the CaM specific binding, supporting the concept that these agents act by binding to CaM and thereby inhibiting histamine release. TFP and W-7 inhibited histamine release in the absence and in the presence of increasing concentrations of extracellular Ca 2+. These results emphasize the possible role of CaM in the control of histamine secretion from human basophils.

Effects of trifluoperazine and verapamil on the hydro-osmotic response to antidiuretic hormone in the urinary bladder of the toad.

To investigate the role of the intracellular calcium-calmodulin complex in the hydro-osmotic response to antidiuretic hormone (ADH), the effects of trifluoperazine (TFP), a well-established inhibitor of calmodulin-mediated functions, and of verapamil (V), a calcium entry blocker, were examined in the urinary bladder of the toad, a model for the late distal tubule and the collecting duct of the mammalian nephron. Preincubation of the hemibladders with TFP at serosal concentrations of 10(-5) and 10(-4) M was without effect on basal water flow but markedly reduced the maximal hydroosmotic response to ADH (50 mU/ml) in a dose-dependent manner as compared to control hemibladders (23.60 +/- 1.23 vs. 42.17 +/- 4.18 mg/min per hemibladder (10(-5) M TFP) and 5.43 +/- 0.59 vs. 52.50 +/- 4.67 mg/min per hemibladder (10(-4) M TFP). This inhibitory effect of TFP on the ADH-stimulated osmotic water flow persisted in the presence of naproxen (10(-5) M), a known inhibitor of prostaglandin synthesis. The hydro-osmotic response to cyclic adenosine 3',5' monophosphate (cAMP, 10(-3) M) was also significantly reduced in TFP-pretreated tissues (11.68 +/- 1.84 vs. 32.83 +/- 3.14 mg/min per hemibladder), suggesting a post-cAMP inhibitory effect of TFP. V (10(-4) M) had no effect on basal water flow but significantly reduced the hydro-osmotic effect of 50 mU/ml ADH (15.17 +/- 1.05 vs. 38.00 +/- 3.39 mg/min per hemibladder). In contrast, cAMP-stimulated osmotic water flow was significantly stimulated in V-treated tissues (48.07 +/- 1.95 vs. 27.13 +/- 1.50 mg/min per hemibladder).(ABSTRACT TRUNCATED AT 250 WORDS)

Trifluoperazine inhibits 45Ca2+ uptake and catecholamine secretion and synthesis in adrenal medullary cells.

In isolated adrenal medullary cells, carbamylcholine and high K+ cause the calcium-dependent secretion of catecholamines with a simultaneous increase in the synthesis of 14C-catecholamines from [14C]tyrosine. In these cells, trifluoperazine, a selective antagonist of calmodulin, inhibited both the secretion and synthesis of catecholamines. The stimulatory effect of carbamylcholine was inhibited to a greater extent than that of high K+. The inhibitory effect of trifluoperazine on carbamylcholine-evoked secretion of catecholamines was not overcome by an increase in either carbamylcholine or calcium concentration, showing that inhibition by trifluoperazine occurs by a mechanism distinct from competitive antagonism at the cholinergic receptor and from direct inactivation of calcium channels. Doses of trifluoperazine that inhibited catecholamine secretion and synthesis also inhibited the uptake of radioactive calcium by the cells. These results suggest that trifluoperazine inhibits the secretion and synthesis of catecholamines mainly due to its inhibition of calcium uptake. Trifluoperazine seems to inhibit calcium uptake by uncoupling the linkage between calcium uptake by uncoupling the linkage between cholinergic receptor stimulation and calcium channel activation.

Biological properties of a calcium-modulator protein from Phycomyces blakesleeanus

1. 1. A modulator protein having properties similar to calmodulin-like proteins could be detected in Phycomyces the first day of growth. 2. 2. The modulator protein from Phycomyces was partially purified to a specific activity of 9,000 Units/mg protein. 3. 3. The modulator protein was similar to calmodulin with respect to: (a) the ability to stimulate a calcium-plus-calmodulin-dependent cAMP phosphodiesterase from bovine brain; (b) the inhibitory effect of trifluoperazine in this process; (c) the stimulation of the (Ca 2+ + Mg 2+)-ATPase from human erythrocyte membranes. 4. 4. Maximum effect of modulator protein in the above mentioned reactions was achieved at micromolar calcium concentrations.

Calcium dependence and contraction in somite formation

The existence of a calcium-dependent contractile process in the formation of somites from segmental plate mesoderm was investigated using a Ca 2+ agonist and Ca 2+ and calmodulin antagonists. The contributions of cell movement and apical constriction in the segmentation process were assessed using SEM of normal and drug-treated somite and segmental plate tissue. Explants that contained segmental plates of stage 14–15 chick embryos were cultured on vitelline membranes in calcium and magnesium-free (CMF) Hanks' solution, liquid culture medium, and medium containing drugs. Ca 2+ ionophore A23187 promoted the rapid completion of one new somite pair. CMF halted segmentation. The Ca 2+ antagonists verapamil and papaverine reversibly inhibited segmentation. Theophylline did not inhibit segmentation, suggesting that the effects of the Ca 2+ antagonists are not due to inhibition of phosphodiesterase activity. These results suggest that somitogenesis is Ca 2+-dependent. Two drugs that inhibit the binding of calmodulin, chlorpromazine and trifluoperazine (TFP), halted segmentation. The inhibitory effect of TFP was reversible. The effects of TFP on somites were compared with those of cytochalasin D. The contribution of microtubules to cell shape and movement in somitogenesis was examined by incubation with nocodazole, a reversible inhibitor of tubulin polymerization. Cell elongation and somitogenesis were inhibited.

Inhibition by trifluoperazine of glycogenolytic effects of phenylephrine, vasopressin, and angiotensin II.

The effects of trifluoperazine on the activation of glycogenolysis by various hormones were studied in perfused rat liver. Trifluoperazine significantly inhibited glycogenolytic effect of phenylephrine and angiotensin II by lowering maximal response, and that of vasopressin by shifting the dose-response curve to the right, while alpha-antagonist phentolamine was inhibitory only to phenylephrine. Phosphorylase activation of phenylephrine was inhibited by trifluoperazine in parallel with glycogenolytic response. The increase in 45Ca2+ efflux induced by phenylephrine, angiotensin II, and vasopressin was also inhibited by the agent. These inhibitory effects of trifluoperazine were not related to the change in tissue cyclic AMP or cyclic GMP levels. On the other hand, neither the glycogenolytic effect of glucagon, cyclic AMP, and N6,O2-dibutyryl cyclic AMP nor phosphorylase activation by glucagon was affected by trifluoperazine. Thus, trifluoperazine specifically inhibits the activation of glycogenolysis by Ca2+-dependent hormones.