CC BY
6MEDICAL SCIENCES
MARKERS OF THE TUBULAR KIDNEY DAMAGE IN GENTAMICIN-INDUCED KIDNEY INJURY
TREATED WITH TAURINE
Drachuk V.,
PhD, associate professor Department of Pharmacology Zamorskii I., Doctor of Medical Sciences, professor Department of Pharmacology Shchudrova T.,
PhD, associate professor Department of Pharmacology Kopchuk T.,
PhD, associate professor Department of Pharmacology Goroshko O.,
PhD, associate professor Department of Pharmaceutical Botany and Pharmacognosy
Dikal M.
PhD, associate professor Department of Bioorganic and Biological Chemistry and Clinical Biochemistry Bukovinian State Medical University, Chernivtsi, Ukraine DOI: 10.5281/zenodo.6575777
Abstract
Despite significant advances in drug treatment and the introduction of renal replacement therapy, mortality from acute kidney damage remains high at about 35-70%, and the need for effective and safe pharmacological correction of nephropathy of various etiologies requires the pharmaceutical industry to expand directions. , as the prevalence of renal pathology in the general population is growing steadily every year. Antibacterial agents are no exception - aminoglycosides, which are potentially nephrotoxic and cause damage and death of tubular epithelial cells with the development of nephropathy in 30% of patients. Therefore, the study of new high-performance nephroprotectors is still relevant, and the main requirements for drugs of this class are safety, ability to influence the main mechanisms of damage and protection of renal tissue, antioxidant, anti-inflammatory, membrane-protective properties. Taurine is a sulfur-containing amino acid that plays an important role in the regulation of many physiological processes in the human body and has osmoregulatory h and antioxidant properties. The purpose of the study is to study the nephroprotective potential of taurine in gentamicin nephropathy, the ability to normalize the energy supply of nephrocytes and to show cytoprotective action.
Keywords: nephroprotective effect, taurine, gentamici-induced nephropathy.
Even though the concept of acute kidney damage in medicine has existed for more than 50 years, the issues of screening, diagnosis, effective prevention and treatment of this pathology remain unresolved, as loss of renal function is often associated with multiorgan failure. For the pharmaceutical community and medicine, the issue of finding new and improving existing methods of pharmacotherapy with the inclusion of etiological, pathogenetic and symptomatic routes of correction has become more acute.
To date, the main mechanisms of reactive oxygen species (ROS) generation in this pathology have been identified and it has been proven that reducing ROS formation and oxidative stress are potential pharmacotherapeutic points for the treatment of acute kidney injury (AKI), which in most cases is ischemia with acute hypoxia, which is often inevitable in clinical situations such as kidney transplantation, trauma, rhabdomyolysis, heart failure, sepsis, use of nephrotoxic drugs [1, 2, 3, 4]. Protection of renal tissue
in such situations requires the use of nephroprotectors, but today they are not separated into a separate group of drugs, and information about the nephroprotective properties of some drugs is fragmentary and not always proven. It is promising to find polytropic drugs that can counteract hypoxia and reduce the development of renal ischemia, affecting both renal circulation and the actual processes of free radical oxidation [5].
An important niche in the structure of general acute kidney damage is occupied by nephropathy caused by various nephrotoxins [6]. Antibacterial drugs are often the primary cause of toxic drug nephropathies, which significantly limits their use in clinical practice and, at the same time, they occupy a leading place in the complex treatment of infectious and inflammatory pathologies. Aminoglycosides are no exception -antibacterial agents with a broad spectrum of antimicrobial action and bactericidal effect, which are potentially nephrotoxic and cause damage and death of tubular epithelial cells with the development of
nephropathy. According to the literature, gentamicin accumulates in the cortical layer of the kidneys, where its concentration is ten times higher than the concentration in blood plasma and causes nephrotoxic reactions in 30% of patients [7, 8]. Nephrotoxic effects are realized due to the binding of phospholipids to the apical membranes of nephrocytes and the accumulation of proximal tubules in cells, which leads to disruption of phospholipid metabolism with subsequent destabilization of lysosomal membranes and release into the cytosol of a large number of enzymes.
In this regard, our attention was drawn to taurine -sulfoamino acid, which is directly involved in the regulation of many physiological processes in the body by influencing the distribution of extracellular and intracellular fluxes of calcium ions, osmoregulation, conjugation of retinoids and xenobiotics, antitoxic and neu-romodulatory effect and promoting the normalization of metabolism [9].
The aim of research was to experimentally determine the recovery of nephrocyte energy and the presence of cytoprotective potential of taurine in the development of gentamicin nephropathy in rats.
Materials and methods
Research was conducted on 24 non-linear white male rate weighting 130-180 g, maintained under the standard vivarium conditions with a constant temperature and humidity, free access to water and food. Animals were randomly divided into 3 groups (n=7): I group - intact control, II group - gentamicin-induced AKI, III group - rats, which were administered with Taurine («Sigma, USA) at a dose of 100 mg/kg. Taurine was injected intraperitoneally in a form of water solution 40 min after each gentamicin injection. Gen-tamicin-induced AKI was caused by single daily injection of 4% gentamicin sulfate solution («Galychfarm», Ukraine) at a dose of 80 mg/kg over 6 days [10]. Functional state of kidneys was evaluated on the 7th day under the conditions of water load (intragastric administration of water (37°C) in amount of 5% body weight). Rats were sacrificed, blood, urine and kidney samples were taken for analysis. The activity of GGTP in urine was determined by reaction with L-g-glutamyl-n-ni-troanilide [11] using a test kit of "Reagent" (Ukraine). Succinate dehydrogenase (SDH) activity was determined in the kidney homogenate by the potassium fer-ricyanide reduction reaction [12].
All studies were conducted in accordance with European Union Directive 2010/63/EU «On the protection of animals used for scientific purposes».
The results were processed using SPSS Statistics 17.0 software. The differences between the samples
were estimated using the Student's t test (in case of normal distribution). The minimum significance level was accepted at p<0.05.
Results and discussion
It is proved that an important trigger for the development of pathobiochemical reactions that occur when nephrocytes are damaged is energy deficiency, which in turn leads to necrosis and apoptosis. In turn, hypoxia leads to the formation of complex cascade reactions, which are based on successive changes in the properties of mitochondrial enzyme complexes. In the first (compensatory) stage, the NAD / NADH-dependent oxidation pathway is activated, which does not cause significant changes in the concentration of intracellular macroergic phosphates and the functional activity of epitheliocytes. However, further oxygen deficiency is accompanied by suppression of respiratory chain function, resulting in a decrease in ATP content [13]. The development of energy deficiency causes dysfunction of active ion transport channels, destabilization of cell membranes and the development of mitochondrial dysfunction. The main manifestations of the latter are a decrease in ATP levels, activation of cell death mechanisms and enhanced production of ROS mitochondria [14]. Mitochondrial function is closely linked to maintaining cellular redox balance due to the presence of a powerful antioxidant system.
Taurine selected for research is an important component of antioxidant protection. Literature data show a multifaceted complex use of taurine in various fields of medicine, but experimentally sound reviews of their use in AKI are extremely rare, so the task of studying their impact on the course of AKI of various etiologies remains relevant [15].
Since oxidative stress plays a key role in the pathogenesis of gentamicin-induced AKI, directly increasing the production of ROS in mitochondria, the study of succinate dehydrogenase (SDH) activity with its compensatory protective, energy-modulating function reveals the restoration of functional activity of nephrocytes.
In this experimental study, the simulation of gentamicin nephropathy, as expected, led to severe renal dysfunction as a manifestation of the toxic effects of antibacterial agents. In the group of animals of model pathology, a significant decrease in the activity of the SDH enzyme by 4.5 times was observed, which indicates a violation of the energy-synthesizing function of nephrocyte mitochondria (see Fig. 1). In the taurine group, the activity of SDH was significantly increased by
c '53
-m
o
!-h
CP
00 S
X
C
(U
ta C
'[3 o
M
13
S c
14
12
10
6 4 2 0
□ Control
Gentamicin-Induced AKI
□ Gentamicin induced AKI+ Taurine (100 mg/kg)
8
Figure 1. Succinate dehydrogenase activity in the kidney tissue of rats with gentamicin-induced AKI Note. Statistically significant differences with group data: intact control - # (p<0,05), Gentamicin-Induced AKI - * (p<0,05).
An important confirmation of the protective cytoprotective effect of the drug is the determination of the activity of the enzyme gamma-glutamyl transpeptidase (GGTP) in urine, an enzyme localized in the brush border of the epithelium of the proximal renal tubules, increased activity which is a marker of damage
Thus, in animals of the model pathology group, an increase in enzyme activity of 18.5 times was observed. In contrast, taurine showed a 4.8-fold decrease in enzyme activity (p <0.01), confirming its cytoprotective effect. (see Fig. 2).
and necrosis of renal tubular epithelial cells.
6 5,5 5 4,5 O 4 ¿i 3,5 3
|2,5
1,5 1
0,5 0
□ Control
□ Gentamicin-Induced AKI
□ Gentamicin-Induced AKI+Taurine
(100 mg/kg)
Figure 2. Gamma-glutamyltranspeptidase activity in the urine of rats with gentamicin-induced AKI Note. Statistically significant differences with group data: intact control - # (p<0,05), Gentamicin-Induced AKI - * (p<0,05).
Conclusion. Based on the results of the research, the nephrotoxic effect of gentamicin was established, which leads to significant damage to the cells of the proximal tubules of the kidneys, which is manifested by a violation of the energy supply of their functional capacity. Therapeutic and prophylactic use of taurine reduced the degree of damage and prevented the
occurrence of significant renal impairment, which confirms their nephroprotective activity. A significant increase in the activity of the SDH enzyme with the use of taurine was found, which indicates an increase in the energy-synthesizing function of nephrocytes under the influence of the studied drugs. The cytoprotective effect was verified by a decrease in the activity of
GGPT in the group of taurine-treated animals, limiting the prevalence of histopathological changes.
The results of experimental studies indicate nephroprotective activity of taurine, which is realized by normalization of energy supply of nephrocytes and cytoprotective action, which justifies the feasibility of further studies to expand the range of taurine and optimize pharmacotherapy of renal pathology.
References
1. Oxidant mechanisms in renal injury and disease / B. B. Ratliff et al. Antioxid. Redox Signal. 2016. Vol. 25, № 3. Р. 119-146. doi: 10.1089/ars.2016.6665.
2. Kanagasundaram N. S. Pathophysiology of ischaemic acute kidney injury. Annals of clinical biochemistry: International Journal of laboratory medicine. 2015. Vol. 52, №. 2. P. 193-205.
3. Lillie M. A. Barnett, Cummings B.S. Nephrotoxicity and renal pathophysiology: a contemporary perspective. Toxicological Sciences. 2018. Vol. 164, № 2. P. 379-390. doi.org/10.1093/toxsci/kfy159.
4. Molecular nephrology: types of acute tubular injury / D. De Oliveira B. et al. Nat Rev Nephrol. 2019. Vol. 15, № 10. P. 599-612. doi:10.1038/s41581-019-0184-x.
5. Kam T. L., Emmanuel P., Burdmann A. Acute kidney injury: global health alert. J. Nephropathol. 2013. Vol. 2, № 2. P. 90-97.
6. Drug-associated acute kidney injury: who's at risk? / E. L. Joyce et al. Pediatr Nephrol. 2017. Vol. 32, № 1. P. 59-69. doi: 10.1007/s00467-016-3446-x.
7. Experimental gentamicin nephrotoxicity and agents that modify it: a mini-review of recent research / B. H. Ali et al. Basic Clin Pharmacol Toxicol. 2011. Vol. 109. № 4. P. 225-232.
8. Udupa V., Prakash V. Gentamicin induced acute renal damage and its evaluation using urinary biomarkers in rats. Toxicol Rep. 2018. Vol. 6. P. 91-99. doi: 10.1016/j.toxrep.2018.11.015.
9. Long-term prognosis after acute kidney injury (AKI): what is the role of baseline kidney function and recovery? A systematic review / S. Sawhney et al. BMJ Open. 2015. Vol. 5(1). e006497. doi: 10.1136/bmjopen-2014-006497.
10. Ostermann M., Joannidis M. Acute kidney injury 2016: diagnosis and diagnostic workup. Crit Care. 2016. Vol. 20, № 1. P. 299. doi: 10.1186/s13054-016-1478-z
11. Urinary gamma-glutamyl transferase-to-creatinine ratio as an indicator of tubular function in bence jones proteinuria / E. E. Yesil et al. Ren Fail. 2014. Vol. 36, № 3. P. 390-392. doi: 10.3109/0886022X.2013.867784.
12. Ananth S., Mathivanan V., Ganesh P. Studies on the impact of heavy metal Arsenic trioxide on freshwater fish grass carp, tenopharyngodon idella in relation to enzyme activity of Succinate Dehydrogenase. International Journal of Toxicology and Applied Pharmacology. 2014. № 4 (1). P. 1-5.
13. Ronco C. Acute kidney injury biomarkers: Are we Ready for the Biomarker Curve? Cardiorenal Med. 2019. Vol. 9(6). P.354-357. doi: 10.1159/000 503443.
14. Koza Y. Acute kidney injury: current concepts and new insights. J Inj Violence Res. 2016. Vol. 8, №1. P. 58-62.
15. Marcinkiewicz J., Kontny E. Taurine and inflammatory diseases. Amino Acids. 2014. Vol. 46, №.1. P. 7-20. doi: 10.1007/s00726-012-1361-4.
