Perhexiline Therapy in Patients with Type 2 Diabetes: Dissociation Between Potentiation of Nitric Oxide Signalling and Changes in Insulin Resistance

2021 ◽  
Author(s):  
Cher-Rin Chong ◽  
Saifei Liu ◽  
Hasan Imam ◽  
Tamila Heresztyn ◽  
Benedetta Sallustio ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cardiovascular Disease ◽  
Insulin Sensitivity ◽  
Fasting Blood Glucose ◽  
Systolic Heart Failure ◽  
No Donor ◽  
Insulin Sensitizer ◽  
Markers Of Inflammation ◽  
Before And After ◽  
Sensitizing Effect

Abstract Purpose: Perhexiline (Px) has previously been utilized primarily in the treatment of otherwise refractory angina pectoris and/or systolic heart failure. In recent years, Px has also shown increasing promise as a potential chemotherapeutic agent. Px inhibits carnitine palmitoyltransferases 1 and 2 (CPT1, CPT2), which control uptake of long-chain fatty acids into mitochondria and thus represent the rate-limiting steps in their metabolism. However, occasional cases of hypoglycaemia have been reported in Px-treated patients, raising the possibility that Px may also increase sensitivity to insulin. Furthermore, Px increases anti-aggregatory responses to nitric oxide (NO), an effect which may parallel insulin sensitization. No previous studies have examined either the effect of Px on insulin sensitivity, or the relationship of such putative changes with effects on NO signalling. We therefore sought to examine these relationships in patients with stable T2D and cardiovascular disease.Methods: In 30 patients with concomitant T2D and cardiovascular disease, Px was initiated, and dosage was titrated to reach therapeutic range and to prevent toxicity. Investigations were performed before and after 2 weeks, to examine changes in insulin sensitivity, platelet responsiveness to the anti-aggregatory effects of the NO donor sodium nitroprusside (SNP), as well as other markers of inflammation and modulators of NO signaling.Results: Px substantially potentiated inhibition of ADP-induced platelet aggregation by SNP (from 16.7±3.0 to 27.3±3.7%; p=0.005). Px did not change fasting blood glucose concentrations and reduced insulin sensitivity (HOMA-IR score increased from median of 4.47 to 6.08; p=0.028), via increasing fasting plasma insulin concentrations (median 16.5 to 19.0 mU/L: p=0.014). Increases in SNP responses tended (r=-0.30; p=0.11) to be reciprocally related to increases in HOMA-IR. No patient developed symptomatic hypoglycaemia, nor was there any other short-term toxicity of Px.Conclusions: In patients with stable T2D and cardiovascular disease, Px is not an insulin sensitizer, and does not normally induce hypoglycaemia. These results effectively dissociate the NO-sensitizing effect of Px from variability in insulin signaling.

Sodium Nitrite Increases Regional Blood Flow in Patients with Sickle Cell Disease.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 2328-2328
Author(s):  
A. Kyle Mack ◽  
Roberto F. Machado ◽  
Vandana Sachdev ◽  
Mark T. Gladwin ◽  
Gregory J. Kato
Keyword(s):  
Nitric Oxide ◽  
Blood Flow ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Forearm Blood Flow ◽  
Regional Blood Flow ◽  
Cell Disease ◽  
No Donor ◽  
No Donors ◽  
Before And After

Abstract Patients with sickle cell disease have decreased nitric oxide bioavailability, and studies from several groups have confirmed a blunted response to various NO donors in humans and mice with sickle cell disease. Recently published studies show that nitrite induces vasodilation in humans, apparently mediated by conversion of nitrite to NO. This study is designed to determine the potential therapeutic effect of intra-arterial nitrite infusion to restore nitric oxide dependent blood flow in the forearms of patients with sickle cell disease. Venous occlusion strain gauge plethysmography is used to measure the change of forearm blood flow in patients with sickle cell disease, before and after sequential brachial artery infusions of increasing doses of sodium nitrite. In addition, NO responsiveness before and after nitrite infusion is measured by test doses of the NO donor sodium nitroprusside (SNP). Six patients have completed the study and enrollment is continuing. These data indicate that nitrite promotes regional blood flow in patients with sickle cell disease, albeit with a blunted response compared to our healthy control subjects, in whom we previously have found increased blood flow up to 187% with comparable dosing. The significant but blunted response is consistent with the state of nitric oxide resistance to NO donors that has been seen by several groups in patients and mice with SCD. Additionally, we find in these patients that nitrite partially restores SNP responsiveness, with baseline maximal SNP responses more than doubling on average following nitrite infusion, although this finding is preliminary. No adverse effects of nitrite were seen in these six patients. Our early results support a role for nitrite as an NO donor effective in restoring NO-dependent blood flow in patients with sickle cell disease. Additional translational studies are warranted to evaluate the therapeutic effects of systemic nitrite dosing. Table 1. Forearm Blood Flow Response to Nitrite Infusion Nitrite Dose (micromole/min) Sickle Cell Disease Historical Controls P< .0001 (ANOVA) 0.4 5 +/−7.2% N=6 22 +/−3.2% N=10 4 15 +/− 11% N=6 Not infused 40 49 +/− 8.9% N=6 187 +/− 16%N=18 Table 2. Nitrite Effect on Nitroprusside Responsiveness SNP Dose (micrograms/min) Pre-Nitrite Post-Nitrite P= .02 (RM-ANOVA) N=6 0.8 +21 +/− 5.6% +33 +/− 8.3% 1.6 +15 +/− 5.9% +62 +/− 15.1% 3.2 +29 +/− 6.3% +67 +/− 11.5%

Role of nitric oxide and cAMP in prostaglandin-induced pial arterial vasodilation

1995 ◽  
Vol 268 (4) ◽  
pp. H1436-H1440 ◽  
Author(s):  
W. M. Armstead
Keyword(s):  
Nitric Oxide ◽  
Topical Administration ◽  
No Donor ◽  
Cyclic Monophosphate ◽  
Cranial Window ◽  
Pial Artery ◽  
Before And After ◽  
Arterial Dilation ◽  
Synthase Inhibitor

The present study was designed to investigate the role of nitric oxide (NO), guanosine 3',5'-cyclic monophosphate (cGMP), and adenosine 3',5'-cyclic monophosphate (cAMP) in the vasodilator response to prostaglandin (PG)I2 and PGE2 in newborn pigs equipped with a closed cranial window. PGI2 (1–100 ng/ml) produced pial arterial dilation that was blunted by nitro-L-arginine (L-NNA, 10(-6) M), an NO synthase inhibitor (9 +/- 1 vs. 2 +/- 1%, 21 +/- 1 vs. 5 +/- 3% for 1 and 100 ng/ml PGI2 respectively, n = 6; means +/- SE). PGI2-induced vasodilation was associated with increased cortical periarachnoid cerebrospinal fluid (CSF) cGMP, and these changes in cGMP were blocked by L-NNA (386 +/- 8 and 1,054 +/- 30 fmol/ml vs. 266 +/- 6 and 274 +/- 4 fmol/ml for control and PGI2 100 ng/ml before and after L-NNA respectively, n = 6). In contrast, PGI2-associated changes in CSF cAMP were unchanged by L-NNA (1,021 +/- 25 and 2,703 +/- 129 fmol/ml vs. 980 +/- 23 and 2,636 +/- 193 fmol/ml for control, PGI2 100 ng/ml before and after L-NNA, respectively, n = 6). PGE2 elicited similar changes in pial artery diameter and cyclic nucleotides; vasodilation and changes in CSF cGMP also being similarly inhibited by L-NNA. After L-NNA, topical administration of the NO donor sodium nitroprusside (SNP, 10(-9) M) increased pial artery diameter up to the resting level before L-NNA and partially restored the vasodilation elicited by PGI2 and PGE2.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin sensitivity is mediated by the activation of the ACh/NO/cGMP pathway in rat liver

2004 ◽  
Vol 287 (3) ◽  
pp. G527-G532 ◽  
Author(s):  
Maria P. Guarino ◽  
Nina C. Correia ◽  
W. Wayne Lautt ◽  
M. Paula Macedo
Keyword(s):  
Nitric Oxide ◽  
Insulin Sensitivity ◽  
Muscarinic Receptors ◽  
Wistar Rats ◽  
No Donor ◽  
Parasympathetic Nerves ◽  
Cgmp Pathway ◽  
Male Wistar Rats ◽  
Oxide Synthase

The hepatic parasympathetic nerves and hepatic nitric oxide synthase (NOS) are involved in the secretion of a hepatic insulin sensitizing substance (HISS), which mediates peripheral insulin sensitivity. We tested whether binding of ACh to hepatic muscarinic receptors is an upstream event to the synthesis of nitric oxide (NO), which, along with the activation of hepatic guanylate cyclase (GC), permits HISS release. Male Wistar rats (8–9 wk) were anesthetized with pentobarbital sodium (65 mg/kg). Insulin sensitivity was assessed using a euglycemic clamp [the rapid insulin sensitivity test (RIST)]. HISS inhibition was induced by antagonism of muscarinic receptors (atropine, 3 mg/kg iv) or by blockade of NOS [ NG-nitro-l-arginine methyl ester (l-NAME), 1 mg/kg intraportally (ipv)]. After the blockade, HISS action was tentatively restored using a NO donor [3-morpholynosydnonimine (SIN-1), 5–10 mg/kg ipv] or ACh (2.5–5 μg·kg−1·min−1 ipv). SIN-1 (10 mg/kg) reversed the inhibition caused by atropine (RIST postatropine 137.7 ± 8.3 mg glucose/kg; reversed to 288.3 ± 15.5 mg glucose/kg, n = 6) and by l-NAME (RIST post-l-NAME 152.2 ± 21.3 mg glucose/kg; reversed to 321.7 ± 44.7 mg glucose/kg, n = 5). ACh did not reverse HISS inhibition induced by l-NAME. The role of GC in HISS release was assessed using 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 5 nmol/kg ipv), a GC inhibitor that decreased HISS action (control RIST 237.6 ± 18.6 mg glucose/kg; RIST post-ODQ 111.7 ± 6.2 mg glucose/kg, n = 5). We propose that hepatic parasympathetic nerves release ACh, leading to hepatic NO synthesis, which activates GC, triggering HISS action.

Lack of role for nitric oxide in cholinergic modulation of myocardial contractility in vivo

2001 ◽  
Vol 281 (1) ◽  
pp. H198-H206 ◽  
Author(s):  
George J. Crystal ◽  
Xiping Zhou ◽  
Syed Alam ◽  
Agnieszka Piotrowski ◽  
Guochang Hu
Keyword(s):  
Nitric Oxide ◽  
Myocardial Contractility ◽  
Vagal Stimulation ◽  
Negative Inotropic Effect ◽  
Cholinergic Modulation ◽  
No Donor ◽  
Flow Transducer ◽  
Before And After ◽  
Synthase Inhibitor

Despite intensive investigation, the role of nitric oxide (NO) in cholinergic modulation of myocardial contractility remains unresolved. The left anterior descending coronary artery of 34 anesthetized, open-chest dogs was perfused via an extracorporeal circuit. Segmental shortening (SS) was measured with ultrasonic crystals and coronary blood flow (CBF) was measured with an ultrasonic flow transducer. An intracoronary infusion of ACh (20 μg/min) was performed, with CBF held constant, under baseline and during dobutamine, CaCl2, or amrinone at doses increasing SS by ∼50% (10 μg/min, 15 mg/min, and 300 μg/min ic, respectively). ACh-induced responses during dobutamine were also assessed following treatment with the NO synthase inhibitor N G-nitro-l-arginine methyl ester (l-NAME; 300 μg/min ic for 15 min). The effects of sodium nitroprusside (SNP; 80 μg/min ic), an exogenous NO donor, bradykinin (2.5 μg/min ic), a nonmuscarinic releaser of endothelial NO, and bilateral vagal stimulation (before and after l-NAME) were evaluated during dobutamine. ACh had no effect on SS under baseline or during CaCl2, but it decreased SS during dobutamine or amrinone (−23 ± 4% and −30 ± 5%, respectively). Vagal stimulation also reduced SS during dobutamine. l-NAME did not alter the ACh- or vagal-induced decreases in SS during dobutamine. Neither SNP nor bradykinin affected SS during dobutamine. In conclusion, ACh and vagal stimulation have a negative inotropic effect during stimulation of the β-adrenergic receptors that is independent of NO. The persistence of this effect during amrinone suggests that a mechanism downstream from adenylate cyclase is involved.

Blockade of hepatic nitric oxide synthase causes insulin resistance

1999 ◽  
Vol 277 (1) ◽  
pp. G101-G108 ◽  
Author(s):  
Parissa Sadri ◽  
W. Wayne Lautt
Keyword(s):  
Nitric Oxide ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Methyl Ester ◽  
Nitric Oxide Synthase ◽  
Insulin Response ◽  
No Donor ◽  
Peripheral Insulin Resistance ◽  
Oxide Synthase ◽  
Liver Insulin Resistance

The hypothesis was tested that insulin sensitivity, previously shown to depend on a functional hepatic parasympathetic reflex, was mediated by hepatic production of nitric oxide (NO). Insulin sensitivity was measured using the rapid insulin sensitivity test. N-nitro-l-arginine methyl ester (l-NAME, 2.5 and 5.0 mg/kg iv) and N-monomethyl-l-arginine (l-NMMA, 0.73 mg/kg), nitric oxide synthase (NOS) antagonists, caused insulin resistance in rats. Intraportal administration ofl-NAME at a dose of 1.0 mg/kg significantly reduced the response to insulin (54.9 ± 5.2%); however, administration of the same dose ofl-NAME intravenously did not cause a significant decrease in insulin response. Intraportal, but not intravenous, administration of 3-morpholinosydnonimine (SIN-1, 5.0 mg/kg), a NO donor, partially reversed the insulin resistance caused byl-NMMA. Intraportal administration of SIN-1 (10.0 mg/kg) completely restored insulin sensitivity after l-NMMA or surgical denervation of the liver. Insulin resistance produced by denervation was not further increased by NOS blockade. These results suggest that blockade of NOS causes peripheral insulin resistance secondary to blockade of the hepatic parasympathetic reflex release of hepatic insulin-sensitizing substance in response to insulin.

Nitric oxide exerts feedback inhibition on EDHF-induced coronary arteriolar dilation in vivo

2000 ◽  
Vol 279 (2) ◽  
pp. H459-H465 ◽  
Author(s):  
Yasuhiro Nishikawa ◽  
David W. Stepp ◽  
William M. Chilian
Keyword(s):  
Nitric Oxide ◽  
Feedback Inhibition ◽  
Coronary Microcirculation ◽  
No Donor ◽  
Control Value ◽  
Before And After ◽  
Arteriolar Vasodilation ◽  
Dose Dependent ◽  
Cytochrome P 450

We tested the hypothesis that nitric oxide (NO) inhibits endothelium-derived hyperpolarizing factor (EDHF)-induced vasodilation via a negative feedback pathway in the coronary microcirculation. Coronary microvascular diameters were measured using stroboscopic fluorescence microangiography. Bradykinin (BK)-induced dilation was mediated by EDHF, when NO and prostaglandin syntheses were inhibited, or by NO when EDHF and prostaglandin syntheses were blocked. Specifically, BK (20, 50, and 100 ng · kg−1 · min−1 ic) caused dose-dependent vasodilation similarly before and after administration of N G-monomethyl-l-arginine (l-NMMA) (3 μmol/min ic for 10 min) and indomethacin (Indo, 10 mg/kg iv). The residual dilation to BK withl-NMMA and Indo was completely abolished by suffusion of miconazole or an isosmotic buffer containing high KCl (60 mM), suggesting that this arteriolar vasodilation is mediated by the cytochrome P-450 derivative EDHF. BK-induced dilation was reduced by 39% after inhibition of EDHF and prostaglandin synthesis, and dilation was further inhibited by combined blockade withl-NMMA to a 74% reduction in the response. This suggests an involvement for NO in the vasodilation. After dilation to BK was assessed with l-NMMA and Indo, sodium nitroprusside (SNP, 1–3 μg · kg−1 · min−1ic), an exogenous NO donor, was administered in a dose to increase the diameter to the original control value. Dilation to BK was virtually abolished when administered concomitantly with SNP duringl-NMMA and Indo ( P < 0.01 vs. before SNP), suggesting that NO inhibits EDHF-induced dilation. SNP did not affect adenosine- or papaverine-induced arteriolar dilation in the presence ofl-NMMA and Indo, demonstrating that the effect of SNP was not nonspecific. In conclusion, our data are the first in vivo evidence to suggest that NO inhibits the production and/or action of EDHF in the coronary microcirculation.

Hepatic glutathione and nitric oxide are critical for hepatic insulin-sensitizing substance action

2003 ◽  
Vol 284 (4) ◽  
pp. G588-G594 ◽  
Author(s):  
Maria P. Guarino ◽  
Ricardo A. Afonso ◽  
Nuno Raimundo ◽  
João F. Raposo ◽  
M. Paula Macedo
Keyword(s):  
Nitric Oxide ◽  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Methyl Ester ◽  
Insulin Action ◽  
Wistar Rats ◽  
Treated Group ◽  
Synthesis Inhibitor ◽  
No Donor ◽  
Hepatic Glutathione

We tested the hypothesis that hepatic nitric oxide (NO) and glutathione (GSH) are involved in the synthesis of a putative hormone referred to as hepatic insulin-sensitizing substance HISS. Insulin action was assessed in Wistar rats using the rapid insulin sensitivity test (RIST). Blockade of hepatic NO synthesis with N G-nitro-l-arginine methyl ester (l-NAME, 1.0 mg/kg intraportal) decreased insulin sensitivity by 45.1 ± 2.1% compared with control (from 287.3 ± 18.1 to 155.3 ± 10.1 mg glucose/kg, P < 0.05). Insulin sensitivity was restored to 321.7 ± 44.7 mg glucose/kg after administration of an NO donor, intraportal SIN-1 (5 mg/kg), which promotes GSH nitrosation, but not after intraportal sodium nitroprusside (20 nmol · kg−1 · min−1), which does not nitrosate GSH. We depleted hepatic GSH using the GSH synthesis inhibitor l-buthionine-[ S,R]-sulfoximine (BSO, 2 mmol/kg body wt ip for 20 days), which reduced insulin sensitivity by 39.1%. Insulin sensitivity after l-NAME was not significantly different between BSO- and sham-treated animals. SIN-1 did not reverse the insulin resistance induced by l-NAME in the BSO-treated group. These results support our hypothesis that NO and GSH are essential for insulin action.

Ticlopidine Facilitates the Deaggregation of Human Platelets Aggregated by Thrombin

1994 ◽  
Vol 71 (01) ◽  
pp. 091-094 ◽  
Author(s):  
M Cattaneo ◽  
B Akkawat ◽  
R L Kinlough-Rathbone ◽  
M A Packham ◽  
C Cimminiello ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Platelet Aggregation ◽  
Prostaglandin E1 ◽  
Human Platelet ◽  
Adenosine Diphosphate ◽  
Human Platelets ◽  
Before And After ◽  
Normal Human ◽  
Platelet Aggregates ◽  
Induced Aggregation

SummaryNormal human platelets aggregated by thrombin undergo the release reaction and are not readily deaggregated by the combination of inhibitors hirudin, prostaglandin E1 (PGE1) and chymotrypsin. Released adenosine diphosphate (ADP) plays an important role in the stabilization of thrombin-induced human platelet aggregates. Since ticlopidine inhibits the platelet responses to ADP, we studied thrombin-induced aggregation and deaggregation of 14C-serotonin-labeled platelets from 12 patients with cardiovascular disease before and 7 days after the oral administration of ticlopidine, 250 mg b.i.d. Before and after ticlopidine, platelets stimulated with 1 U/ml thrombin aggregated, released about 80–90% 14C-serotinin and did not deaggregate spontaneously within 5 min from stimulation. Before ticlopidine, hirudin (5× the activity of thrombin) and PGE1 (10 μmol/1) plus chymotrypsin (10 U/ml) or plasmin (0.06 U/ml), added at the peak of platelet aggregation, caused slight or no platelet deaggregation. After ticlopidine, the extent of platelet deaggregation caused by the same inhibitors was significantly greater than before ticlopidine. The addition of ADP (10 μmol/1) to platelet suspensions 5 s after thrombin did not prevent the deaggregation of ticlopidine-treated platelets. Thus, ticlopidine facilitates the deaggregation of thrombin-induced human platelet aggregates, most probably because it inhibits the effects of ADP on platelets.

The Effect on Health of Some Cardiovascular Risk Factors

2017 ◽  
Vol 68 (10) ◽  
pp. 2237-2242
Author(s):  
Germaine Savoiu Balint ◽  
Mihaiela Andoni ◽  
Ramona Amina Popovici ◽  
Laura Cristina Rusu ◽  
Ioana Citu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Vascular Reactivity ◽  
Vascular Wall ◽  
Dose Effect ◽  
Organ Bath ◽  
Before And After ◽  
Specific Receptors ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Relaxing Response

Arterial endothelium produces a large ramge of active factors which are indispensable for modulation of vasomotor tone and maintenance of vascular wall integrity. From these factors, nitric oxide (NO), wich is released by the endothelial cells as a response to acetylcholine or adenosine action on specific receptors, plays an important role.NO is the result of oxidation process of L-arginine into L-citrulline, under the action of endothelial nitric oxide synthase (NOSe), wich is activated by intracelluar Ca2+ - calmodulin complex . Our study, performed in isolated organ bath, analyzed vascular reactivity of 12 guinea pigs� thoracic aorta rings. After phenylephrine -PHE 10-5 mol/L precontraction, the dose-effect curves for acetylcoline � ACH, adenosine 5� phosphate - 5�ADP and sodium nitroprusside � SNP were determined, before and after incubation of preparation, for 1 hour, with 5% hydrosoluble cigarettes smoke extract (CSE). Statistic analysis, performed with the use of t pair test and ANOVA parametric test, showed that incubation of vascular preparation with 5% CSE has increased the contractile response to PHE 10-5 mol/L (p[0.05), has reduced the endothelium-dependent relaxing response to ATP 10-5 mol/L (p[0.001) and 5�ADP 10-5 molo/L (p[0.001), but has not significantly modified the endothelium-independent relaxing response to SNP 10-5 mol/L (p=0.05). As a conclusion, vascular rings incubation with 5% CSE induced a decrease of endothelium NO synthesis under the action of AXH and 5�ADP, but did not change the smooth muscle fiber respomse in the presence of NO released by SNP.

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