Hemodynamic responses elicited by systemic injections of flavin adenine dinucleotide in anesthetized rats

Flavin Adenine Dinucleotide-Related Adverse Event Necessitating Cardiopulmonary Resuscitation in an Infant

Mitochondrial rescue drugs, such as vitamin B2, are a treatment modality which can be considered in unexplained cases of cardiac arrest or impaired consciousness in which mitochondrial diseases are considered in the differential. Although case reports exist of children developing a drop in their blood pressure following administration of intravenous flavin adenine dinucleotide (FAD) sodium as vitamin B2, we present the first reported case of a child requiring cardiopulmonary resuscitation (CPR) following FAD sodium infusion for severe bradycardia and hypotension. Intravenous infusion of FAD sodium should be administered as slowly as possible, with careful monitoring of blood pressure and heart rate.

Flavine adenine dinucleotide inhibits pathological cardiac hypertrophy and fibrosis through activating short chain acyl-CoA dehydrogenase

Short-chain acyl-CoA dehydrogenase (SCAD), the rate-limiting enzyme for fatty acid β-oxidation, has a negative regulatory effect on pathological cardiac hypertrophy and fibrosis. Furthermore, flavin adenine dinucleotide (FAD) can enhance the expression and enzyme activity of SCAD. However, whether FAD can inhibit pathological cardiac hypertrophy and fibrosis remains unclear. Therefore, we observed the effect of FAD on pathological cardiac hypertrophy and fibrosis. FAD significantly inhibited PE-induced cardiomyocyte hypertrophy and AngII-induced cardiac fibroblast proliferation. In addition, FAD ameliorated pathological cardiac hypertrophy and fibrosis in SHR. FAD significantly increased the expression and enzyme activity of SCAD. Meanwhile, ATP content was increased, the content of free fatty acids and reactive oxygen species were decreased by FAD in vivo and in vitro. In addition, molecular dynamics simulations were also used to provide insights into the structural stability and dynamic behavior of SCAD. The results demonstrated that FAD may play an important structural role on the SCAD dimer stability and maintenance of substrate catalytic pocket to increase the expression and enzyme activity of SCAD. In conclusion, FAD can inhibit pathological cardiac hypertrophy and fibrosis through activating SCAD, which may be a novel effective treatment for pathological cardiac hypertrophy and fibrosis, thus prevent them from developing into heart failure.

Sex-specific programming of hypertension in offspring of late-gestation diabetic rats

BACKGROUND

The intrauterine environment strongly influences adult disease susceptibility. We used a rat model of third-trimester maternal diabetes to test the hypothesis that adult offspring exposed to hyperglycemia in utero display increased blood pressure and alterations in vascular responsiveness.

METHODS

Diabetes was induced by streptozotocin injection to pregnant rats on gestation day 13 (term 21 d) and partially controlled with insulin injections. Hemodynamic function was evaluated in 6-12-mo-old offspring.

RESULTS

Male but not female offspring of diabetic mothers (ODM) had significantly increased blood pressure as compared with controls; heart rate (HR) was similar. For both sexes, HR baroreflex responses were similar as were in vivo hemodynamic responses to angiotensin II, nitric oxide synthase inhibition, and ganglionic blockade. Aortic contractility to angiotensin II was similar in the two groups. Nitric oxide synthase inhibition and the Cu/Zn superoxide dismutase inhibitor diethyldithiocarbamate, but not the superoxide dismutase-mimetic Tempol, significantly increased contractile responses to angiotensin II in controls but not ODM. Reduced nicotinamide adenine dinucleotide phosphate-stimulated superoxide production was greater in male ODM than in controls (P < 0.05).

CONCLUSION

Exposure to hyperglycemia in utero results in sex-specific cardiovascular changes in adult offspring. Impaired nitric oxide-reactive oxygen species signaling may play a significant role in the hemodynamic phenotype of ODM.

Flavin adenine dinucleotide may release preformed stores of nitrosyl factors from the vascular endothelium of conscious rats

This study determined whether flavin adenine dinucleotide (FAD) may elicit vasodilation in conscious rats via release of preformed endothelium-derived nitrosyl factors. Injections 1-6 (inj(1-6)) of FAD (2.5 micromol/kg, IV) elicited pronounced and equivalent vasodilator responses in saline-treated rats. Inj(1) of FAD elicited pronounced vasodilation in L-NAME-treated rats pretreated with the nitric oxide (NO) synthesis inhibitor, NG-nitro-L-arginine (L-NAME; 50 micromol/kg, IV), whereas Inj(2-6) elicited progressively smaller responses such that inj(6) elicited minor responses. The vasodilator responses elicited by the endothelium-dependent agonist, acetylcholine, were markedly attenuated in L-NAME-treated rats that had received inj(1-6) of FAD but not in saline-treated rats that had received inj(1-6) of FAD. The vasodilator actions of L-S-nitrosocysteine and the NO donor, sodium nitroprusside, were not diminished after the injections of FAD in saline- or in L-NAME-treated rats. Binding studies demonstrated that the densities of muscarinic M3 receptors were increased in thoracic aorta endothelium of rats treated with L-NAME + inj(1-6) of saline or L-NAME + inj(1-6) of FAD as compared to rats treated with saline + inj(1-6) of saline or saline + inj(1-6) of FAD. The progressive loss of response to injections of FAD in L-NAME-treated rats coupled with the loss of response to acetylcholine suggests that FAD elicits the use-dependent depletion of vesicular pools of nitrosyl factors in endothelial cells that cannot be replenished in the absence of NO synthesis.