Implication of protein kinase A for a hepato-protective mechanism of milrinone pretreatment

Milrinone is better choice for controlled low central venous pressure during hepatectomy: A randomized, controlled trial comparing with nitroglycerin

BACKGROUND

To explore the feasibility and effectiveness of controlled low central venous pressure(CLCVP)induced by milrinone during hepatectomy, and its influence on perioperative hemodynamics, blood loss and patients' recovery, comparing with the traditional method by nitroglycerin.

METHODS

52 patients who underwent elective open hepatectomy were enrolled in the study and randomly divided into two groups: milrinone (M) group and nitroglycerin (NG) group. Milrinone was infused with the rate of 0.5 μg/kg/min in group M, while nitroglycerin was given 0.2-0.5 μg/kg/min in group NG to maintain CVP≤ 5 mmHg during liver resection. The demographic variables, data of the operative procedure and intraoperative hemodynamics were recorded. The postoperative recovery profiles and pre- and post-operative haematological markers of vital organs were also collected and compared.

RESULTS

1. The blood loss of group M, no matter during liver resection or in the whole procedure, was both less than that of group NG (P < 0.05), so did the hemoglobin detected by blood gas analysis (P < 0.05). Meanwhile, time of hepatectomy and hepatic hilum occlusion were shorter in group M (P < 0.05). 2. Compared with the NG group, cardiac index (CI) and stroke volume index (SVR) were higher in group M in the operation. The norepinephrine dosage necessary in the operation was of no difference in two groups (P > 0.05). 3. Drainage indwelling time and postoperative hospital stay of group M were shorter than that of group NG (P < 0.05). Most of the blood biomarkers increased on postoperative day (POD)-1, and returned to the preoperative level on POD-7 without inter-group difference (P > 0.05). Brain natriuretic peptide precursor (Pro-BNP) in group M was higher than NG group on POD-1 (P < 0.05), and the statistical difference disappeared on POD-7.

CONCLUSION

Milrinone can effectively maintain a controlled low central venous pressure during hepatectomy. Compared with nitroglycerin, milrinone can reduce the amount of blood loss, with the benefit of better manifestation of hemodynamics and enhanced postoperative recovery.

Pretreatment with a Phosphodiesterase-3 Inhibitor, Milrinone, Reduces Hepatic Ischemia-Reperfusion Injury, Minimizing Pericentral Zone-Based Liver and Small Intestinal Injury in Rats

BACKGROUND Severe pericentral zone (zone 3)-based liver injury (LI) may become intractable, with allograft dysfunction after liver transplantation. The phosphodiesterase-3 inhibitor, milrinone, has been reported to attenuate hepatic ischemia-reperfusion injury (IRI). This study clarified how hepatic IRI involved zone 3-based LI, in which zone milrinone was effective, and whether milrinone could improve small intestinal injury (SII) with hepatic IRI. MATERIAL AND METHODS Rats were divided into sham, ischemia-reperfusion (IR), or IR+milrinone groups (n=13 per group). Milrinone was administered intraportally via intrasplenic injection, and whole hepatic ischemia was induced for 30 min. Five hours after reperfusion, serum chemistry and histopathological findings were compared. Expression of CD34 for the detection of altered sinusoidal endothelium as sinusoidal capillarization and cleaved caspase-3 as an apoptosis marker were analyzed via immunohistochemistry. Survival rates were examined after 45 min of whole hepatic ischemia. RESULTS Serum aspartate aminotransferase and direct bilirubin levels were significantly decreased in the IR+milrinone group compared with those of the IR group. The degree of LI, sinusoidal capillarization and apoptosis at zone 3 in the IR group was significantly increased compared with those at the periportal zone (zone 1). These findings at zone 3 in the IR group were improved in the IR+milrinone group. SII with villus congestion and apoptosis in the IR group was significantly attenuated in the IR+milrinone group. The 7-day survival rate was significantly elevated in the IR+milrinone group as compared with that of the IR group. CONCLUSIONS A hepatic IRI model caused zone 3-based LI and SII, which were attenuated by intraportal administration of milrinone.

Development of a Rapid Mass Spectrometric Determination of AMP and Cyclic AMP for PDE3 Activity Study: Application and Computational Analysis for Evaluating the Effect of a Novel 2-oxo-1,2-dihydropyridine-3-carbonitrile Derivative as PDE-3 Inhibitor

A simple, quick, easy and cheap tandem mass spectrometry (MS/MS) method for the determination of adenosine monophosphate (AMP) and cyclic adenosine monophosphate (cAMP) has been newly developed. This novel MS/MS method was applied for the evaluation of the inhibitory effect of a novel 2-oxo-1,2-dihydropyridine-3-carbonitrile derivative, also named DF492, on PDE3 enzyme activity in comparison to its parent drug milrinone. Molecule DF492, with an IC₅₀ of 409.5 nM, showed an inhibition of PDE3 greater than milrinone (IC₅₀ = 703.1 nM). To explain the inhibitory potential of DF492, molecular docking studies toward the human PDE3A were carried out with the aim of predicting the binding mode of DF492. The presence of different bulkier decorating fragments in DF492 was pursued to shift affinity of this novel molecule toward PDE3A compared to milrinone in accordance with both the theoretical and experimental results. The described mass spectrometric approach could have a wider potential use in kinetic and biomedical studies and could be applied for the determination of other phosphodiesterase inhibitor molecules.

Sevoflurane has postconditioning as well as preconditioning properties against hepatic warm ischemia-reperfusion injury in rats

PURPOSE

Ischemia-reperfusion (IR) injury is inevitable after liver transplantation and liver resection with inflow occlusion. Sevoflurane has been widely used during hepatobiliary surgery and was reported to exhibit preconditioning (PreC) properties against hepatic IR injury; however, its postconditioning (PostC) properties remain unknown. This study examined whether a clinically applicable dose of sevoflurane has PostC and PreC properties against hepatic IR injury and roles of heme oxygenase-1 (HO-1).

METHODS

Warm ischemia was induced in male Wistar rats, excluding the sham group, for 1 h, followed by 3 h of reperfusion. Group C received propofol from 60 min before ischemia until the end of the experimental procedure. In the SPreC and SPostC groups, propofol was replaced by 2.5% sevoflurane for 30 min from 35 min before ischemia in the SPreC group and for 30 min from 5 min before reperfusion in the SPostC group. The SPreC+Z and SPostC+Z groups received a HO-1 inhibitor, zinc protoporphyrin (Znpp), 60 min before ischemia, and sevoflurane PreC and PostC were induced.

RESULTS

Serum aspartate aminotransferase, alanine aminotransferase, and lactic dehydrogenase levels, and histological damage scores in the SPreC and SPostC groups were significantly lower than those in group C. Inhibiting HO-1 with Znpp partially blocked these protective effects of sevoflurane. Sevoflurane PreC and PostC significantly increased the number of HO-1-positive Kupffer cells in comparison with group C, and Znpp prevented sevoflurane-induced HO-1 expression.

CONCLUSION

PostC and PreC by sevoflurane at a clinically applicable dose have equally protective effects against hepatic IR injury by increasing HO-1 expression.

Phase I clinical trial of olprinone in liver surgery

PURPOSE

Post-hepatectomy liver failure is one of the most serious complications liver surgeons must overcome. We previously examined olprinone, a selective phosphodiesterase III inhibitor, and demonstrated its hepatoprotective effects in rats and pigs. We herein report the results of a phase I clinical trial of olprinone in liver surgery (UMIN000004975).

METHODS

Twenty-three patients who underwent hepatectomy between 2011 and 2015 were prospectively registered. In the first 6 cases, olprinone (0.1 μg/kg/min) was administered for 24 h from the start of surgery. In the remaining 17 cases, olprinone (0.05 μg/kg/min) was administered from the start of surgery until just before the transection of the liver parenchyma. The primary endpoint was safety, and the secondary endpoint was efficacy. For the evaluation of efficacy, the incidence of post-hepatectomy liver failure in 20 hepatocellular carcinoma patients was externally compared with 20 propensity score-matched patients.

RESULTS

No intraoperative side effects were observed, and the morbidity rates in the analyzed cohorts were acceptable. The rate of post-hepatectomy liver failure frequency tended to be lower in the olprinone group.

CONCLUSIONS

The safety of olprinone in liver surgery was confirmed. The efficacy of olprinone will be re-evaluated in clinical trials.

Beyond Preconditioning: Postconditioning as an Alternative Technique in the Prevention of Liver Ischemia-Reperfusion Injury

Liver ischemia/reperfusion injury may significantly compromise hepatic postoperative function. Various hepatoprotective methods have been improvised, aiming at attenuating IR injury. With ischemic preconditioning (IPC), the liver is conditioned with a brief ischemic period followed by reperfusion, prior to sustained ischemia. Ischemic postconditioning (IPostC), consisting of intermittent sequential interruptions of blood flow in the early phase of reperfusion, seems to be a more feasible alternative than IPC, since the onset of reperfusion is more predictable. Regarding the potential mechanisms involved, it has been postulated that the slow intermittent oxygenation through controlled reperfusion decreases the burst production of oxygen free radicals, increases antioxidant activity, suppresses neutrophil accumulation, and modulates the apoptotic cascade. Additionally, favorable effects on mitochondrial ultrastructure and function, and upregulation of the cytoprotective properties of nitric oxide, leading to preservation of sinusoidal structure and maintenance of blood flow through the hepatic circulation could also underlie the protection afforded by postconditioning. Clinical studies are required to show whether biochemical and histological improvements afforded by the reperfusion/reocclusion cycles of postconditioning during early reperfusion can be translated to a substantial clinical benefit in liver resection and transplantation settings or to highlight more aspects of its molecular mechanisms.

Effect of milrinone on the inflammatory response and NF-kB activation in renal ischemia-reperfusion injury in mice

BACKGROUND

Milrinone increases intracellular adenosine 3',5'-cyclic monophosphate concentration and enhances vascular relaxation. Nuclear factor-kappa B (NF-kB) plays a key role in inflammatory responses during ischemia-reperfusion (I/R) injury. We aimed to investigate the effect of milrinone on the inflammatory responses and NF-kB activation in renal I/R injury in mice.

METHODS

Thirty C57BL/6 mice were allocated into 3 groups. In group S (n = 10), only right nephrectomy was done. In group C (n = 10), the left kidney was subjected to 30 min of ischemia after right nephrectomy. In group M (n = 10), milrinone (5 µg/kg) was administered before ischemia. After 24 hours of reperfusion, the serum creatinine was measured, kidney samples were obtained for histology, and expressions of NF-kB and proinflammatory cytokines were analyzed.

RESULTS

In group C, the serum creatinine concentration was markedly elevated, compared with group S. Creatinine concentration in group M was also elevated, but it was significantly lower than that in group C. Histologic evidence of renal damage was severe in group C, but it was improved in group M. In groups C and M, expression of NF-kB, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-2 (MIP-2) mRNA increased significantly compared with group S (P < 0.05). But group M showed a lower expression of NF-kB, TNF-α, ICAM-1, MCP-1 and MIP-2 mRNA than group C (P < 0.05).

CONCLUSIONS

Milrinone treatment attenuates the renal inflammatory response and activation of NF-kB, resulting in improvement of renal function and tissue injury.

Low central venous pressure with milrinone during living donor hepatectomy

Maintaining a low central venous pressure (CVP) has been frequently used in liver resections to reduce blood loss. However, decreased preload carries potential risks such as hemodynamic instability. We hypothesized that a low CVP with milrinone would provide a better surgical environment and hemodynamic stability during living donor hepatectomy. Thirty-eight healthy adult liver donors were randomized to receive either milrinone (milrinone group, n = 19) or normal saline (control group, n = 19) infusion during liver resection. The surgical field was assessed using a four-point scale. Intraoperative vital signs, blood loss, the use of vasopressors and diuretics and postoperative laboratory data were compared between groups. The milrinone group showed a superior surgical field (p < 0.001) and less blood loss (142 +/- 129 mL vs. 378 +/- 167 mL, p < 0.001). Vital signs were well maintained in both groups but the milrinone group required smaller amounts of vasopressors and less-frequent diuretics to maintain a low CVP. The milrinone group also showed a more rapid recovery pattern after surgery. Milrinone-induced low CVP improves the surgical field with less blood loss during living donor hepatectomy and also has favorable effects on intraoperative hemodynamics and postoperative recovery.