OPC-21268, a non-peptide vasopressin V1 receptor antagonist, inhibited oxytocin- and vasopressin-induced contractions of myometrial strips from rats and from full-term pregnant women. OPC-21268, because of its non-peptide structure, is orally active and has been shown to lower blood pressure in a patient with congestive heart failure and in spontaneously hypertensive rats. It also attenuates vasopressin induced bradycardia in rabbits and pressor responses in rats. It has been demonstrated that OPC-21268 exerts its inhibitory action through binding to the vasopressin V1 receptors in rat liver and kidney. Finally, OPC-21268 was reported to be safe and non-toxic in healthy humans. Merck scientists showed that OPC-21268 had significant affinity for the rOTR and the hOTR. OPC-21268 has been in phase II clinical trials by Otsuka for the treatment of heart failure and hypertension. However, this research has been discontinued.

BAY-41-2272 is a direct and NO-independent soluble guanylate cyclase (sGC) stimulator. It sensitizes sGC to nitric oxide (NO), its physiological stimulator, and contains antiplatelet activity. BAY-41-2272 is an inhibitor of GCS. BAY-41-2272 inhibits platelet aggregation (IC50 = 36 nM) and phenylephrine-induced contractions of rabbit aorta (IC50 = 0.30 uM). BAY-41-2272 also reduces vascular smooth muscle growth through cAMP- and cGMP-dependent PKA and PKG pathways. BAY-41-2272 not only sensitized NO-sensitive GC toward activation by NO but also, with comparable potency, inhibited cGMP degradation by PDE5. BAY-41-2272 may provide a novel therapeutic compound for treating chronic hypoxic pulmonary hypertension.

Perindopril arginine is a stable L-arginine salt of perindopril. Perindopril, a pro-drug, is hydrolyzed to perindoprilat, which inhibits ACE in humans and in animals. It is indicated for the treatment of hypertension, heart failure and coronary artery disease. Perindopril arginine may be used in monotherapy or in combination with other classes of antihypertensive therapy.

Flosequinan is a vasodilator developed for the treatment of heart failure. The drug was marketed under the name Manoplax, however it was withdrawn by the FDA decision since it increased congestive heart failure symptoms. The exact mechanism of flosequinan action is unknown, but there are studies reporting the inhibition of PDE3 activity.

AMISOMETRADINE, a pyrimidinedione-based diuretic, is an isomer of aminometradine with less toxicity and a reasonable diuretic potency.

Deslanoside is a cardiotonic glycoside from the leaves of Digitalis lanata. It is used to treat congestive heart failure and supraventricular arrhythmias due to reentry mechanisms, and to control ventricular rate in the treatment of chronic atrial fibrillation. Deslanoside inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). It also acts on the electrical activity of the heart, increasing the slope of phase 4 depolarization, shortening the action potential duration, and decreasing the maximal diastolic potential.

Digoxin is a cardiac glycoside derived from the purple foxglove flower. In 1785, the English chemist, botanist, and physician Sir William Withering published his findings that Digitalis purpurea could be used to treat cardiac dropsy (congestive heart failure; CHF). Digoxin has been in use for many years, but was not approved by the FDA for treatment of heart failure (HF) until the late 1990s. Another FDA indication for digoxin is atrial fibrillation (AF). Digoxin also has numerous off-label uses, such as in fetal tachycardia, supra-ventricular tachycardia, cor pulmonale, and pulmonary hypertension. Digitoxin inhibits the Na-K-ATPase membrane pump, resulting in an increase in intracellular sodium and calcium concentrations. Increased intracellular concentrations of calcium may promote activation of contractile proteins (e.g., actin, myosin). Digoxin also has Para sympathomimetic properties. By increasing vagal tone in the sinoatrial and atrioventricular (AV) nodes, it slows the heart rate and AV nodal conduction.

Evans Blue (EBD) is an azo dye which has a very high affinity for serum albumin. It can be useful in physiology in estimating the proportion of body water contained in blood plasma. Evans Blue Dye is widely used to study blood vessel and cellular membrane permeability as it is non-toxic, it can be administered as an intravital dye and it binds to serum albumin – using this as its transporter molecule. The EBD–albumin conjugate (EBA) can be: (i) identified macroscopically by the striking blue colour within tissue; (ii) observed by red auto-fluorescence in tissue sections examined by fluorescence microscopy; and (iii) assessed and quantified by spectrophotometry for serum samples, or homogenised tissue. has recently been utilised in mdx mice to identify permeable skeletal myofibres that have become damaged as a result of muscular dystrophy. EBD has the potential to be a useful vital stain of myofibre permeability in other models of skeletal muscle injury and membrane-associated fragility. Evans Blue is a potent inhibitor of L-glutamate uptake into synaptic vesicles. It also inhibits AMPA and kainate receptor-mediated currents (IC50 values are 220 and 150 nM respectively). P2X-selective purinoceptor antagonist.

Fosfructose is a cytoprotective natural sugar phosphate under development by Questcor (formerly Cypros) for the potential treatment of cardiovascular ischemia, sickle cell anemia and asthma. Fosfructose acts by stimulating anaerobic glycolysis which generates adenosine triphosphate under ischemic conditions and improve the cellular energy metabolism in ischemic and hypoperfused tissues. Hypoxia forces ischemic tissue to anaerobic glycolysis for energy, which yields two molecules of ATP per glucose in contrast to 36 molecules of ATP generated during oxidative phosphorylation . Addition of exogenous Fosfructose can produce two more molecules of ATP in an uncompensated anaerobic environment and hence facilitate the recovery of ischemia tissue. Fosfructose breaks down into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate, which will further break down into two molecules of pyruvate and finally produce two molecules of ATP. Other mechanisms include inhibition of the generation of oxygen free radicals by neutrophils, stabilization of cell membranes, and maintainance of the correct xanthine dehydrogenase/oxidase ratio by preventing the depletion of phosphorylated compounds in ischemic tissues. In myocardial infarction patients, FDP can improve the hemodynamic parameters, attenuate ECG proven ischemic injury and arrhythmia, prevent ATP and creatine phosphate depletion from ischemic myocardium, reduce infarct size, and increase survival rate. Exogenously administered Fosfructose has also been proven beneficial for a variety of other ischemic organs, such as liver, kidney, bowel and even brain as a consequence of its ability to penetrate to the blood brain barrier. Fosfructose trisodium had been in phase I clinical trials for the treatment of heart transplant rejection. Fosfructose trisodium had been in phase II clinical trials for the treatment of heart failure, perioperativ eischaemia and reperfusion injury. Fosfructose trisodium had been in phase III clinical trials for the treatment of sickle cell anaemia. However, all these research has been discontinued. In China, FDP has been approved and marketed as a commercial drug.

D-ribose, a naturally occurring pentose carbohydrate, and a key component in the adenosine triphosphate (ATP) molecule. D-ribose was studied for congestive heart failure. In addition was discovered, that D-ribose significantly reduced clinical symptoms in patients suffering from fibromyalgia and chronic fatigue syndrome. Recently was published an article where were described, that d-Ribose reacted with the N-terminal valinyl residues of hemoglobin (Hb), thus producing glycated hemoglobin (HbA1c). It is known, that HbA1c is the most important marker of hyperglycemia in diabetes mellitus, which prompts future studies to explore whether D-ribose could also lead to diabetic complications.