Alperen Kutay Yıldırım

Dr. Alperen Kutay Yıldırım

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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8 February 2025 in Medicina
Verified
Journal Article
Open access
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HDHuseyin Demirtas
Huseyin Demirtas
AÖAbdullah Özer
Abdullah Özer
AYAlperen Kutay Yıldırım
Alperen Kutay Yıldırım
ADAli Dogan Dursun
Ali Dogan Dursun
ŞSşaban cem Sezen
şaban cem Sezen
Mustafa ArslanMustafa Arslan
Mustafa Arslan
Background and Objectives: Ischemia–reperfusion (I/R) injury can affect multiple distant organs following I/R in the lower extremities. BPC-157’s anti-inflammatory and free radical-neutralizing properties suggest its potential in mitigating ischemia–reperfusion damage. This study evaluates the protective effects of BPC-157 on remote organ damage, including the kidneys, liver, and lungs, in a rat model of skeletal muscle I/R injury. Materials and Methods: A total of 24 male Wistar albino rats were randomly divided into four groups: sham (S), BPC-157(B), lower extremity I/R(IR) and lower extremity I/R+BPC-157(I/RB). Some 45 min of ischemia of lower extremity was followed by 2 h of reperfusion of limbs. BPC-157 was applied to groups B and I/RB at the beginning of the procedure. After 2 h of reperfusion, liver, kidney and lung tissues were harvested for biochemical and histopathological analyses. Results: In the histopathological examination, vascular and glomerular vacuolization, tubular dilation, hyaline casts, and tubular cell shedding in renal tissue were significantly lower in the I/RB group compared to other groups. Lung tissue showed reduced interstitial edema, alveolar congestion, and total damage scores in the I/RB group. Similarly, in liver tissue, sinusoidal dilation, necrotic cells, and mononuclear cell infiltration were significantly lower in the I/RB group. Additionally, the evaluation of TAS, TOS, OSI, and PON-1 revealed a statistically significant increase in antioxidant activity in the liver, lung, and kidney tissues of the I/RB group. Conclusions: The findings of this study demonstrate that BPC-157 exerts a significant protective effect against distant organ damage in the liver, kidneys, and lungs following lower extremity ischemia–reperfusion injury in rats.

20 March 2025 in Turkish Journal of Vascular Surgery
Verified
Journal Article
Open access
PDF file
HDHuseyin Demirtas
Huseyin Demirtas
AYAlperen Kutay Yıldırım
Alperen Kutay Yıldırım
AÖAbdullah Özer
Abdullah Özer
ADAli Dogan Dursun
Ali Dogan Dursun
ŞSşaban cem Sezen
şaban cem Sezen
Mustafa ArslanMustafa Arslan
Mustafa Arslan
Aim: Lower extremity ischemia-reperfusion (IR) injury can lead to substantial skeletal muscle damage and systemic complications, primarily driven by oxidative stress and inflammation. In addition to its well-known glucose-lowering effects, metformin possesses antioxidant and anti-inflammatory properties that may confer protection against tissue damage caused by IR. This study aims to evaluate the potential protective effects of metformin on skeletal muscle injury using a rat model of lower extremity IR.Material and Methods: A total of twenty-four male Wistar albino rats were randomly divided into four experimental groups: Control (C), Ischemia-Reperfusion (IR), IR with metformin at 4 mg/kg (IR+M4), and IR with metformin at 8 mg/kg (IR+M8). Ischemia was induced by clamping the infrarenal aorta for 45 minutes, followed by a reperfusion period of 120 minutes. In the treatment groups, metformin was administered intraperitoneally at the onset of ischemia. Gastrocnemius muscle tissues were harvested for subsequent histopathological and biochemical evaluations, including measurements of Total Antioxidant Status (TAS), Total Oxidant Status (TOS), and Oxidative Stress Index (OSI).Results: Histopathological analysis demonstrated a significant reduction in muscle atrophy, degeneration, leukocyte infiltration, and fiber fragmentation in the IR+M8 group compared to the IR group. Biochemical assessments showed that TAS levels were considerably elevated, whereas TOS and OSI levels were markedly reduced in the metformin-treated groups, with the most prominent effects observed at the higher dosage of 8 mg/kg.Conclusion: The findings indicate that metformin exerts a dose-dependent protective effect against skeletal muscle injury resulting from lower extremity ischemia-reperfusion in rats. These protective properties are likely due to metformin’s antioxidant and anti-inflammatory mechanisms, highlighting its potential therapeutic value in mitigating IR-induced tissue damage.

Verified
Journal Article
Open access
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AYAlperen Kutay Yıldırım
Alperen Kutay Yıldırım
ADAHMET ONUR DAŞTAN
AHMET ONUR DAŞTAN
MEMeric Demeli Ertus
Meric Demeli Ertus
MEMESHER ENSARİOGLU
MESHER ENSARİOGLU
KKKubilay Karabacak
Kubilay Karabacak
BPBilge Pehlivanoglu
Bilge Pehlivanoglu
Background/Objectives: Body Protection Compound-157 (BPC 157) is a stable gastric pentadecapeptide with cytoprotective, pro-angiogenic, and nitric oxide (NO)-modulating properties that has gained increasing attention for its therapeutic potential. Although vasodilatory effects have been demonstrated in animal models, functional evidence in human arterial tissue remains limited. This study investigated the effects of BPC 157 on vascular tone in human internal mammary artery (IMA) rings and evaluated the contribution of endothelial NO signaling. Methods: Residual IMA segments obtained from elective coronary artery bypass graft surgeries (n = 12) were dissected into endothelium-intact and endothelium-denuded rings. Following equilibration, the rings were challenged by phenylephrine (PheE; 3 × 10−6 M) to induce contraction. Cumulative concentration–response curves of BPC 157 (0.01–1 mg/mL) for five consecutive doses were constructed. The involvement of NO was assessed by BPC 157 dose–response curves in the nitric oxide synthase (NOS) inhibitor Nω-nitro-L-arginine methyl ester (L-NAME; 10−6 M) pre-incubated rings. Maximum force of contraction, area under the curve, maximum response (Emax), and negative logarithm of the half-maximal effective concentration (pEC50) values were analyzed. Results: BPC 157 produced a concentration-dependent reduction in PheE-induced contraction in both groups, with significantly greater relaxation in endothelium-intact rings (p < 0.05). L-NAME increased contractile responsiveness in intact rings and attenuated BPC 157-induced relaxation. Under NOS inhibition, differences between groups progressively diminished and concentration–response curves converged at higher concentrations. Emax analysis demonstrated that endothelial integrity markedly enhanced maximal vasorelaxation, whereas this advantage was largely abolished after NOS inhibition. Conclusions: BPC 157 induces concentration-dependent vasorelaxation in human arterial tissue, predominantly mediated via an endothelium-dependent NO pathway. Endothelial integrity primarily enhances maximal efficacy, while residual effects indicate additional mechanisms. These findings provide early mechanistic evidence for the vascular activity of BPC 157, although further molecular and in vivo studies are required to clarify its clinical relevance.

28 January 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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SDSuat Doganci
Suat Doganci
MİMehmet İnce
Mehmet İnce
MEMeric Demeli Ertus
Meric Demeli Ertus
NYNadide Ors Yildirim
Nadide Ors Yildirim
BPBilge Pehlivanoglu
Bilge Pehlivanoglu
VYVedat Yildirim
Vedat Yildirim
Chronic venous disease (CVD) is a proqgressive and underestimated condition related to a vicious circle established by venous reflux and endothelial inflammation, leading to vein dilation and histology distortion, including loss of media tone. Sulodexide (SDX) is a drug restoring the glycocalyx that demonstrated endothelial protection and permeability regulation, together with anti-thrombotic and anti-inflammatory roles. In the lab it also exhibited vein contractility function. The aim of the present study was to show the possible role of endothelium and nitric oxide pathway on SDX’s veno-contractile effect on human saphenous veins. The remnants of great saphenous vein (GSV) segments (n = 14) were harvested during coronary artery bypass graft surgery. They were dissected as endothelium-intact (n = 8) and denuded rings (n = 6). First, a viability test was carried out in bath with Krebs–Henseleit solution to investigate a control and basal tension value. After this, cumulative doses of SDX were applied to rings and contraction values were studied in endothelium-intact phenylephrine (PheE, 6 × 10−7 M) pre-contracted vein rings. Finally, endothelium-intact PheE pre-contacted vein rings were treated by nitric oxide synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME, 10−4 M) for 10 min. Contraction protocol was applied, and contraction values were measured in cumulative doses of SDX. The same protocol was applied to endothelium-denuded vein rings to investigate the effect of SDX. Saphenous vein rings showed an increase in contraction to cumulative doses of SDX. In endothel-intact rings, KCL-induced contraction from 92.6% ± 0.3 to 112.9% ± 0.4 with cumulative SDX doses. However, SDX did not show any veno-contractile effect on endothel-denuded rings. In denuded rings contraction responses measured from 94.9% ± 0.3 to 85.2% ± 0.3 with increasing doses of SDX, indicating no significant change. Nitric oxide synthase inhibitor (L-NAME) prohibited the contraction response of the sulodexide in all dosages, indicating that the contractile function of SDX was mediated by endothelial derived nitric oxide. Results of endothel-intact and denuded rings with L-NAME showed a similar incline with denuded rings with SDX only. The results confirmed SDX’s veno-contractile effect in human samples, by means of nitric oxide synthase pathways involvement.

18 January 2022 in Turkish Journal of Vascular Surgery
Verified
Journal Article
Open access
PDF file
AYAlperen Kutay Yıldırım
Alperen Kutay Yıldırım
EÖEge Özgürtaş
Ege Özgürtaş
MİMehmet İnce
Mehmet İnce
Objectives: This study aims to investigate the effect of ketamine on angiogenesis.Materials and methods: Between June 2021 and August 2021, chorioallantoic membrane (CAM) assay cell viability assay protocols and cell viability assay protocols were performed to investigate angiogenesis. While in vivo angiogenic property of ketamine was studied in the chick CAM model, its effect on in vitro cell proliferation was evaluated in 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay.Results: A significant anti-angiogenic effect of ketamine was observed in chick CAM in the in vivo setting, compared to the control group (p<0.001). It showed a strongly dose-dependent inhibitory and cytotoxic effect on endothelial cells.Conclusion: Our study results indicate that ketamine has an anti-angiogenic effect in vitro and in vivo. However, further research is needed to investigate its use in human vascular system as a new anti-angiogenic therapy.

4 September 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MEMESHER ENSARİOGLU
MESHER ENSARİOGLU
AYAlperen Kutay Yıldırım
Alperen Kutay Yıldırım
Background: Intraoperative hypotension is an established risk factor for postoperative acute kidney injury (AKI), but whether arterial waveform morphology adds prognostic information beyond the hypotension burden is unknown. Methods: In this study, 2587 adult surgical cases from the Vital Signs Database (VitalDB) with continuous invasive arterial waveforms and creatinine-based (KDIGO) AKI ascertainment were analyzed retrospectively. Maximal systolic upstroke (dP/dtmax), a late-diastolic pressure-decay descriptor (τ), and a waveform-derived dynamic arterial elastance (Eadyn), modeled as latent-class trajectories and as case-level features, were added to a base logistic model of log-transformed hypotension burden (time-weighted MAP < 65 mmHg), age, sex, and baseline eGFR. Results: AKI occurred in 143 cases (5.5%); the base model had an AUC of 0.725 (95% CI 0.680–0.770). A five-class dP/dtmax solution yielded distinct phenotypes whose membership was nominally associated with AKI (likelihood-ratio p = 0.02) but did not improve discrimination (change in AUC (ΔAUC), 0.008, 95% CI −0.005 to 0.021; optimism-corrected 0.002), and the association was attenuated after clinical adjustment (p = 0.13); τ showed no stable trajectory structure. No feature improved discrimination: the optimism-corrected ΔAUC was ≤0.007, upper confidence limits did not exceed 0.03 on any adequately fitting reference model, and the signal disappeared after adjustment for procedure type and comorbidity. The likelihood-ratio test had 80% power for a ΔAUC of 0.009. Conclusions: Arterial waveform morphology did not improve prediction of postoperative AKI beyond the hypotension burden; overall, these data exclude an incremental gain larger than approximately 0.02–0.03 AUC units.