Effects of olprinone, a phosphodiesterase III inhibitor, on ischemic acute renal failure

Comparing the effects of milrinone and olprinone in patients with congestive heart failure

Phosphodiesterase-3 (PDE3) inhibitors are widely used among patients with congestive heart failure (CHF). However, no studies have compared the cardiovascular outcomes between different PDE3 inhibitors in CHF management. In this report, we retrospectively compared the clinical benefits of two PDE3 inhibitors, milrinone and olprinone, to determine which better controls the progression of CHF. A total of 288 hospitalized patients who received PDE3 inhibitors [(milrinone; n = 77 and olprinone; n = 211, respectively)] for CHF were retrospectively enrolled. The primary endpoint was defined as having a major adverse cardiovascular and cerebrovascular event (MACCE) or cardiac death by day 60. Kaplan-Meier curves and multivariate Cox proportional models were used to compare the outcomes for patients treated with milrinone and olprinone. We found no significant differences in the baseline characteristics between the two groups. In patients treated with milrinone, a greater incidence of a MACCE or cardiac death was observed (log rank; P = 0.005 and P = 0.01, respectively). Milrinone-treated patients with ischemic heart disease and chronic kidney disease (CKD) at stage ≥ 4 presented with greater incidence of MACCE (log rank; P < 0.001 and P = 0.006, respectively). Similarly, these patients were significantly more likely to succumb to cardiac death (log rank; P < 0.001 and P = 0.02). Multivariate Cox proportional hazard models demonstrated that milrinone treatment was an independent predictor of MACCE [hazard ratio (HR) 3.17; 95% CI 1.64-6.10] and cardiac death (HR 2.64; 95% CI 1.42-4.91). Oral administration of a β-blocker at discharge occurred more often in the olprinone-treated patients than in the milrinone-treated patients (63% vs. 29%, P = 0.004). We compared the outcomes of milrinone and olprinone treatment in patients with CHF. Those treated with milrinone were more likely to succumb to a MACCE or cardiac death within 60 days of treatment, which was especially true for patients with ischemic heart disease or CKD.

The effects of tadalafil on renal ischemia reperfusion injury: an experimental study

Many pharmacological agents were investigated for the prevention of renal ischemic reperfusion (I/R) injury as well as the phosphodiesterase (PDE) inhibitors. The aim of the study was to examine the possible renoprotective effect of a member in this family, tadalafil (Td) on I/R injury. Thirty-six Spraque Dawley rats were allocated to six groups as; control, sham, ischemia (I), ischemia/reperfusion (I/R), Td pretreatment ischemia (Td/I) and Td pretreatment ischemia/reperfusion (Td/IR) groups. Right nephrectomy was performed in all groups. Td was dissolved in saline solution and given as a single dose (1mg/kg) through an orogastrictube 60 min before the operation in the Td pretreatment groups. In ischemia group the left renal pedicle was occluded for 45 minutes and after than underwent left nephrectomy. In I/R group left renal pedicle was occluded for 45 minutes, reperfused for 1hour and after then underwent nephrectomy. The left kidneys were evaluated after standard laboratory procedures with regard to tubular morphology, and leukocyte infiltration. The data were analyzed by using Kruskal-Wallis test to determine differences among the groups. A p value of < 0.05 was considered significant. Renal tubular damage was significant increased in the ischemia and I/R group (Groups III and IV) when compared to those in the sham group (Group II), (p = 0.004, 0.004, respectively). Tubular damage, in the Td pretreatment ischemia (Td/I) (Group V) and Td pretreatment ischemia/reperfusion (Td/IR) (Group VI) were less than that in the ischemia group (Group III) (p= 0.010, p= 0.025, respectively). Td administration prior to the renal I/R injury attenuated these morphological disarrangements, which were observed in renal I/R. Tubular necrosis, which may be considered as an important issue of the developing renal injury, was also completely prevented with Td administration.

Epac-Rap signaling reduces cellular stress and ischemia-induced kidney failure

Renal ischemia-reperfusion injury is associated with the loss of tubular epithelial cell-cell and cell-matrix interactions which contribute to renal failure. The Epac-Rap signaling pathway is a potent regulator of cell-cell and cell-matrix adhesion. The cyclic AMP analogue 8-pCPT-2'-O-Me-cAMP has been shown to selectively activate Epac, whereas the addition of an acetoxymethyl (AM) ester to 8-pCPT-2'-O-Me-cAMP enhanced in vitro cellular uptake. Here we demonstrate that pharmacological activation of Epac-Rap signaling using acetoxymethyl-8-pCPT-2'-O-Me-cAMP preserves cell adhesions during hypoxia in vitro, maintaining the barrier function of the epithelial monolayer. Intrarenal administration in vivo of 8-pCPT-2'-O-Me-cAMP also reduced renal failure in a mouse model for ischemia-reperfusion injury. This was accompanied by decreased expression of the tubular cell stress marker clusterin-α, and lateral expression of β-catenin after ischemia indicative of sustained tubular barrier function. Our study emphasizes the undervalued importance of maintaining tubular epithelial cell adhesion in renal ischemia and demonstrates the potential of pharmacological modulation of cell adhesion as a new therapeutic strategy to reduce the extent of injury in kidney disease and transplantation.

Olprinone attenuates excessive shear stress through up-regulation of endothelial nitric oxide synthase in a rat excessive hepatectomy model

After extended hepatectomy, excessive shear stress in the remnant liver causes postoperative liver failure. Olprinone (OLP), a selective phosphodiesterase inhibitor, has been reported to improve microcirculation and attenuate inflammation. The aim of this study was to investigate the effects of OLP on shear stress in rats with an excessive hepatectomy (EHx) model. In this study, EHx comprised 90% hepatectomy with ligation of the left and right Glisson's sheaths in Lewis rats. OLP or saline was intraperitoneally administered with an osmotic pump 48 hours before EHx. To evaluate the shear stress, we measured the portal vein (PV) pressure. We also assessed sinusoidal endothelial cell injury by immunohistochemistry and electron microscopy. Furthermore, we assessed apoptosis in the liver with the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method. Treatment with OLP up-regulated hepatic endothelial nitric oxide synthase (eNOS) expression. The increase in the PV pressure due to Glisson's sheath ligation was attenuated in OLP-treated rats during a 30-minute period after ligation. Treatment with OLP preserved sinusoidal endothelial cells and reduced apoptosis in the remnant liver. The probability of survival in the OLP-treated rats was significantly better than that in the controls (33.3% versus 13.3%). Furthermore, the postoperative eNOS activity in the OLP-treated rats was higher than that in the controls. The administration of Nω-nitro-l-arginine methyl ester to OLP-treated rats eliminated the effects of OLP on PV pressure and survival after EHx. Therefore, we concluded that OLP attenuates excessive shear stress through the up-regulation of eNOS and improves the survival rate after EHx.

Olprinone, a specific phosphodiesterase (PDE)-III inhibitor, reduces the development of multiple organ dysfunction syndrome in mice

Olprinone is a specific phosphodiesterase (PDE)-III inhibitor, which has been found to have anti-inflammatory effects in addition to its main inotropic and peripheral vasodilatory effects. In the present study we investigated the effects of olprinone (0.2mg/kg, i.p.) on the development of zymosan-induced multiple organ failure in mice. Treatment with olprinone attenuated the peritoneal exudation and the migration of polymorphonuclear cells caused by zymosan. Olprinone also attenuated the lung, liver and pancreatic injury, renal dysfunction as well as the increased lung and intestine myeloperoxidase (MPO) activity caused by zymosan. Immunohistochemical analysis for inducible nitric oxide synthase (iNOS), nitrotyrosine, poly(ADP-ribose) (PAR), tumor necrosis factor-α (TNF-α) and interleuchin-1β (IL-1β) revealed positive staining in pancreatic and intestinal tissue obtained from zymosan-injected mice. The degree of staining for nitrotyrosine, iNOS, PAR, TNF-α and IL-1β was markedly reduced in tissue sections obtained from zymosan-injected mice, which had received olprinone. In addition, administration of zymosan caused a severe illness in the mice characterized by significant loss of body weight and a 60% of mortality at the end of observation period (7 days). Treatment with olprinone significantly reduced the development of systemic toxicity, loss in body weight and mortality, caused by zymosan. This study provides evidence that olprinone attenuates the degree of zymosan-induced shock in mice.

Olprinone attenuates the acute inflammatory response and apoptosis after spinal cord trauma in mice

Background

Olprinone hydrochloride is a newly developed compound that selectively inhibits PDE type III and is characterized by several properties, including positive inotropic effects, peripheral vasodilatory effects, and a bronchodilator effect. In clinical settings, olprinone is commonly used to treat congestive cardiac failure, due to its inotropic and vasodilating effects. The mechanism of these cardiac effects is attributed to increased cellular concentrations of cAMP. The aim of the present study was to evaluate the pharmacological action of olprinone on the secondary damage in experimental spinal cord injury (SCI) in mice.

Methodology/Principal Findings

Traumatic SCI is characterized by an immediate, irreversible loss of tissue at the lesion site, as well as a secondary expansion of tissue damage over time. Although secondary injury should be preventable, no effective treatment options currently exist for patients with SCI. Spinal cord trauma was induced in mice by the application of vascular clips (force of 24 g) to the dura via a four-level T5–T8 laminectomy. SCI in mice resulted in severe trauma characterized by edema, neutrophil infiltration, and production of inflammatory mediators, tissue damage, apoptosis, and locomotor disturbance. Olprinone treatment (0.2 mg/kg, i.p.) 1 and 6 h after the SCI significantly reduced: (1) the degree of spinal cord inflammation and tissue injury (histological score), (2) neutrophil infiltration (myeloperoxidase activity), (3) nitrotyrosine formation, (4) pro-inflammatory cytokines, (5) NF-κB expression, (6) p-ERK1/2 and p38 expression and (7) apoptosis (TUNEL staining, FAS ligand, Bax and Bcl-2 expression). Moreover, olprinone significantly ameliorated the recovery of hind-limb function (evaluated by motor recovery score).

Conclusions/Significance

Taken together, our results clearly demonstrate that olprinone treatment reduces the development of inflammation and tissue injury associated with spinal cord trauma.

Apart from the other members of PDE inhibitors' family, enoximone does not enhance renal ischemic reperfusion injury: the effects of enoximone on renal ischemia reperfusion

Many pharmacological agents were investigated for the prevention of renal ischemic reperfusion (IR) injury as well as the phosphodiesterase (PDE) inhibitors. The aim of the study was to examine the possible renoprotective effect of enoximone as a member of this family on IR injury. Thirty-six Wistar-Albino rats were allocated to six groups. Sham (S) and control groups (E1, E2) only received 0.09% NaCl, 5 mg/kg and 10 mg/kg enoximone via caudal caval vein, respectively. In ischemia (I) and treatment groups (IE1, IE2), the rats were subjected to bilateral renal artery occlusion and were given 0.09% NaCl, 5 mg/kg and 10 mg/kg enoximone in the same route, respectively. Bilateral kidneys were removed at the sixth hour of laparotomy for histopathological and biochemical analysis, such as superoxide dismutase, myeloperoxidase, malonyldialdehyde, and nitric oxide end products. Blood samples were taken in order to evaluate renal function tests. The data were analyzed by using one-way analysis of variance, and p < .05 was considered to be statistically significant. The worst results were achieved in ischemia group (p < .05). Treatments groups showed nearly similar findings with this group (p < .05). There was no significant difference between control and sham groups. In this study, we found that apart from the other members of the PDE inhibitors' family, enoximone did not contribute to the attenuation of IR injury of kidney.

Novel pharmacological approaches to the treatment of renal ischemia-reperfusion injury: a comprehensive review

Renal ischemia-reperfusion (I-R) contributes to the development of ischemic acute renal failure (ARF). Multi-factorial processes are involved in the development and progression of renal I-R injury with the generation of reactive oxygen species, nitric oxide and peroxynitrite, and the decline of antioxidant protection playing major roles, leading to dysfunction, injury, and death of the cells of the kidney. Renal inflammation, involving cytokine/adhesion molecule cascades with recruitment, activation, and diapedesis of circulating leukocytes is also implicated. Clinically, renal I-R occurs in a variety of medical and surgical settings and is responsible for the development of acute tubular necrosis (a characteristic feature of ischemic ARF), e.g., in renal transplantation where I-R of the kidney directly influences graft and patient survival. The cellular mechanisms involved in the development of renal I-R injury have been targeted by several pharmacological interventions. However, although showing promise in experimental models of renal I-R injury and ischemic ARF, they have not proved successful in the clinical setting (e.g., atrial natriuretic peptide, low-dose dopamine). This review highlights recent pharmacological developments, which have shown particular promise against experimental renal I-R injury and ischemic ARF, including novel antioxidants and antioxidant enzyme mimetics, nitric oxide and nitric oxide synthase inhibitors, erythropoietin, peroxisome-proliferator-activated receptor agonists, inhibitors of poly(ADP-ribose) polymerase, carbon monoxide-releasing molecules, statins, and adenosine. Novel approaches such as recent research involving combination therapies and the potential of non-pharmacological strategies are also considered.