Opioids Preconditioning Upon Renal Function and Ischemia-Reperfusion Injury: A Narrative Review

Drug Therapies Affecting Renal Function: An Overview

Undesirable side effects of medication are inevitable. Due to the role of the kidneys in clearance and filtration, the renal system faces a unique situation when it comes to the side effects of drugs. It has an important role for different classes of drugs to be excreted, and drugs are a key factor for this system to be at risk. Medications in articles were divided into classes using the standard set by the Saudi Pharmaceutical Journal. Many drug classes cause renal insults. The top six classes were pain killers, antibiotics, proton pump inhibitors, antidiabetics, antihyperlipidemics, and agents for erectile dysfunction. Renal insults caused by these agents could vary in severity. Some drugs could cause nephrotoxicity from one dose, while others may only need continuous monitoring. Different populations also operate under different rules, as some people need dose adjustments while others who are medically free of major illnesses do not. A variety of unfavorable outcomes for the kidney could take place, such as acute kidney injury, chronic kidney disease, and end-stage renal disease, and unfortunately, some of these issues could lead to the need for renal replacement therapies. The outcome of this review paper will help multidisciplinary physicians to understand the renal side effects of the most used drug classes in the Kingdom of Saudi Arabia, their destructive mechanisms, and most importantly, the clinical presentations of renal dysfunction in relation to each class. Emphasizing these adverse effects will prevent future unfavorable outcomes, especially in commonly used drugs that are frequently prescribed for different age groups. Moreover, some of these drugs are considered to be over-the-counter medications, which makes them a serious problem that needs to be handled cautiously.

Sex Differences in Renal Function: Participation of Gonadal Hormones and Prolactin

Kidney pathophysiology is influenced by gender. Evidence suggests that kidney damage is more severe in males than in females and that sexual hormones contribute to this. Elevated prolactin concentration is common in renal impairment patients and is associated with an unfavorable prognosis. However, PRL is involved in the osmoregulatory process and promotes endothelial proliferation, dilatation, and permeability in blood vessels. Several proteinases cleavage its structure, forming vasoinhibins. These fragments have antagonistic PRL effects on endothelium and might be associated with renal endothelial dysfunction, but its role in the kidneys has not been enough investigated. Therefore, the purpose of this review is to describe the influence of sexual dimorphism and gonadal hormones on kidney damage, emphasizing the role of the hormone prolactin and its cleavage products, the vasoinhibins.

Effects of dexmedetomidine on immune function, renal function and inflammatory factors of patients undergoing percutaneous nephrolithotomy under general anesthesia

The present study was designed to determine the effects of dexmedetomidine on immune function, renal function and inflammatory factors in patients undergoing percutaneous nephrolithotomy under general anesthesia. A total of 177 patients with kidney calculi who underwent percutaneous nephrolithotomy in The Second Affiliated Hospital of Fujian Medical University were enrolled, in which 91 patients were treated with dexmedetomidine during surgery (research group) and 86 patients were not sedated during surgery (control group). The vital signs, renal function, inflammatory factors and immune function during surgery between the two groups were compared. Patients in the research group showed improved vital signs, renal function, inflammatory factors and immune function compared with the control group (P<0.05), and also experienced a significantly shorter hospitalization time (P<0.001). Therefore, the present results suggested that with a relatively high safety profile, use of dexmedetomidine for sedation can effectively protect renal and immune functions, and reduce the inflammatory response of patients during percutaneous nephrolithotomy. Thus, dexmedetomidine may have be potentially applied in clinical practice.

Opioid Preconditioning Modulates Repair Responses to Prevent Renal Ischemia-Reperfusion Injury

Progression to renal damage by ischemia-reperfusion injury (IRI) is the result of the dysregulation of various tissue damage repair mechanisms. Anesthetic preconditioning with opioids has been shown to be beneficial in myocardial IRI models. Our main objective was to analyze the influence of pharmacological preconditioning with opioids in renal function and expression of molecules involved in tissue repair and angiogenesis. Experimental protocol includes male rats with 45 min ischemia occluding the left renal hilum followed by 24 h of reperfusion with or without 60 min preconditioning with morphine/fentanyl. We analyzed serum creatinine and renal KIM-1 expression. We measured circulating and intrarenal VEGF. Immunohistochemistry for HIF-1 and Cathepsin D (CTD) and real-time PCR for angiogenic genes HIF-1α, VEGF, VEGF Receptor 2 (VEGF-R2), CTD, CD31 and IL-6 were performed. These molecules are considered important effectors of tissue repair responses mediated by the development of new blood vessels. We observed a decrease in acute renal injury mediated by pharmacological preconditioning with opioids. Renal function in opioid preconditioning groups was like in the sham control group. Both anesthetics modulated the expression of HIF-1, VEGF, VEGF-R2 and CD31. Preconditioning negatively regulated CTD. Opioid preconditioning decreased injury through modulation of angiogenic molecule expression. These are factors to consider when establishing strategies in pathophysiological and surgical processes.

N-Acetylaspartylglutamate (NAAG) Pretreatment Reduces Hypoxic-Ischemic Brain Damage and Oxidative Stress in Neonatal Rats

N-acetylaspartylglutamate (NAAG), the most abundant peptide transmitter in the mammalian nervous system, activates mGluR3 at presynaptic sites, inhibiting the release of glutamate, and acts on mGluR3 on astrocytes, stimulating the release of neuroprotective growth factors (TGF-β). NAAG can also affect N-methyl-d-aspartate (NMDA) receptors in both synaptic and extrasynaptic regions. NAAG reduces neurodegeneration in a neonatal rat model of hypoxia-ischemia (HI), although the exact mechanism is not fully recognized. In the present study, the effect of NAAG application 24 or 1 h before experimental birth asphyxia on oxidative stress markers and the potential mechanisms of neuroprotection on 7-day old rats was investigated. The intraperitoneal application of NAAG at either time point before HI significantly reduced the weight deficit of the ischemic brain hemisphere, radical oxygen species (ROS) content and activity of antioxidant enzymes, and increased the concentration of reduced glutathione (GSH). No additional increase in the TGF-β concentration was observed after NAAG application. The fast metabolism of NAAG and the decrease in TGF-β concentration that resulted from NAAG pretreatment, performed up to 24 h before HI, excluded the involvement mGluR3 in neuroprotection. The observed effect may be explained by the activation of NMDA receptors induced by NAAG pretreatment 24 h before HI. Inhibition of the NAAG effect by memantine supports this conclusion. NAAG preconditioning 1 h before HI results in a mixture of mGluR3 and NMDA receptor activation. Preconditioning with NAAG induces the antioxidative defense system triggered by mild excitotoxicity in neurons. Moreover, this response to NAAG pretreatment is consistent with the commonly accepted mechanism of preconditioning. However, this theory requires further investigation.

Sialic acid-modified dexamethasone lipid calcium phosphate gel core nanoparticles for target treatment of kidney injury

Acute kidney injury (AKI) is a common clinical disease with high morbidity and mortality. Glucocorticoids are drugs that effectively relieve AKI, but the systemic side effects of long-term use limit their use. Herein, we constructed sialic acid-modified dexamethasone sodium phosphate (Dsp)-loaded lipid calcium phosphate gel core nanoparticles (SA-NPs) for the targeted treatment of ischemia-reperfusion (I/R)-induced AKI to improve efficacy and reduce side effects. The obtained nanoparticles could effectively encapsulate Dsp with 66.8% encapsulation efficiency and 4.56% (w/w) drug content. In vitro release indicates that the nanoparticles have a certain sustained release effect and have the characteristics of acid-sensitive release. And SA-NPs significantly increased the cellular uptake and kidney accumulation respectively through the combination of SA and E-selectin receptors overexpressed in inflamed vascular endothelial cells. Besides, the in vivo pharmacokinetic studies showed that Dsp-loaded SA-NPs significantly increased the residence time in the body and their plasma half-life was 1.7 times that of free Dsp. SA-NPs significantly improved the renal function, decreased the level of pro-inflammatory factors, and adjusted the oxidative stress factors and apoptotic proteins compared to free Dsp solution in pharmacodynamic studies. Moreover, little negative effects on blood glucose and bone mineral density were observed. Our study might provide a new strategy for the safe and effective targeting treatment of AKI or other related inflammatory diseases.