Davut Sinan Kaplan

Urotensin Inhibition with Palosuran Could Be a Promising Alternative in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a progressive and a life-threatening disease with its high morbidity and mortality ratios. On searching for new shining targets in pathogenesis, we noticed, in our previous studies, urotensin-II (UII) in systemic sclerosis with potent angiogenic and pro-fibrotic features. Owing to the mimicking properties of UII with endothelin-1 (ET1), we attempted to investigate the effect of palosuran in a PAH rat model. Thirty rats were randomly divided into three groups, with each group comprising 10 rats: group 1 (control group) received the vehicle subcutaneously, instead of monocrotaline (MCT) and vehicle; group 2 (MCT group) received subcutaneous MCT and vehicle; and group 3 (MCT + palosuran group) received subcutaneous MCT and palosuran. Serum UII, ET1, transforming growth factor-β1 (TGF-β1) levels, pulmonary arteriolar pathology of different diameter vessels, and cardiac indices were evaluated. The ET1, TGF-β1, and UII levels were significantly diminished in the treatment group, similar to the controls (p < 0.001). Right ventricular hypertrophy index and mean pulmonary arterial pressure scores were also significantly reduced in the treatment group (p = 0.001). Finally, in the 50–125-μm diameter arterioles, in contrast to Groups 3 and 1, there was a statistically significant thickness (p < 0.01) in the arteriolar walls of rats in Group 2. The treatment effect on arteries of more than 125-μm diameters was found to be valuable but not significant. Owing to its healing effect on hemodynamic, histological, and biochemical parameters of MCT-induced PAH, palosuran as an antagonist of UII might be an optional treatment alternative for PAH.

The Efficiency of a Urotensin II Antagonist in an Experimental Lung Fibrosis Model

Pulmonary fibrosis is a chronic disease. Urotensin II (U-II) is a new peptide with angiogenic and profibrotic features. Therefore, we aim to evaluate the antagonism of U-II with palosuran in an animal model and plan to measure U-II, endothelin-1 (ET-1), and transforming growth factor-β1 (TGF-β1) and their association with lung fibrosis. Thirty Wistar male rats were used in the study and were divided into three groups: group 1, control; group 2, bleomycin-induced lung fibrosis group; and group 3, bleomycin-induced lung fibrosis with treatment palosuran group. U-II level (nanograms per milliliter) was 2.957 ± 0.159 in group1, 3.188 ± 0.122 in group 2, and 2.970 ± 0.165 in group 3 (p = 0.002). The ET-1 level (picograms per milliliter) was 4.486 ± 0.376 in group 1, 9.086 ± 1.850 in group 2, and 4.486 ± 0.376 in group 3 (p < 0.001). The TGF-β1 (nanograms per milliliter) level was 73.143 ± 9.96 in group 1, 84.81 ± 4.73 in group 2, and 77.86 ± 5.77 in group 3 (p = 0.006). Finally, the fibrosis score was 0.7 ± 0.48 in group 1, 4.4 ± 1.34 in group 2, and 3.2 ± 0.63 in group 3 (p < 0.001). There is a statistically significant positive relationship between fibrosis scores and the UT-II, ET-1, and TGF-β1 levels of the experimental lung fibrosis model. We believe U-II is an important mediator in lung fibrosis models, and its antagonism with palosuran could be a new treatment choice for interstitial lung fibrosis, but further studies need to be conducted to verify the findings of the current study.

Preliminary study of efficacy of hyaluronic acid on caustic esophageal burns in an experimental rat model.

BACKGROUND The aim of this study was to investigate the effectiveness of hyaluronic acid on the prevention of esophageal damage and stricture formation after experimental caustic (alkaline) esophageal injury in rats. MATERIALS AND METHODS Twenty-one Wistar albino rats were randomly divided into three groups. A caustic esophageal burn was created following the Gehanno model: Group l (n=7) underwent operation, but no injury; Group 2 (n=7) was injured and left untreated; and Group 3 (n=7) was injured and treated with hyaluronic acid, first topically and then orally by gavage (2×0.3mL; 12.5mg/mL for 7days). The caustic esophageal burn was created by instilling 25% NaOH into the distal esophagus. All rats were euthanized on day 22 for evaluation. The efficacy of hyaluronic acid treatment was assessed histopathologically and biochemically via blood determination of the total antioxidant status (TAS), total oxidant status (TOS), oxidative stress index (OSI), and sulfhydryl group (SH) and lipid hydroperoxidase (LOOH) levels. Statistical analyses were performed. RESULTS Weight gain was significantly lower in Group 2 than in the other two groups (P<0.05). The mean stenosis index, histopathologic damage score, TAS, TOS, OSI, and SH and LOOH levels were higher in Group 2 than in the other two groups. The mean stenosis index, inflammation, TAS, SH and OSI in Group 2 were significantly different than those in the other two groups (P<0.05). CONCLUSION Hyaluronic acid treatment is effective in treating damage and preventing strictures after caustic esophageal burn in rats.

Effects of low-level laser therapy on osteoblastic bone formation and relapse in an experimental rapid maxillary expansion model

AIMS AND OBJECTIVES The aim of this study was to investigate the effects of low-level laser therapy (LLLT) on osteoblastic bone formation and relapse during expansion of rat palatal sutures. MATERIALS AND METHODS Thirty-two Wistar rats were randomly allocated into two groups of 16 rats each. In the first group, LLLT was applied 4 days after expansion commenced. Seven days after expansion, retainers were applied for 10 days. The second group was similarly treated, with the exception of laser therapy. All rats were sacrificed on day 7 (n = 1) (the end of the expansion period; laser group (LG) 1 [LLLT 1] and control group (CG) 1 [control 1]) and day 17 (n = 8) (the end of the retention period; LG 2 [LLLT 2] and CG 2 [control 2]) for histological assessment. RESULTS The LLLT 1 group had significantly higher numbers of osteoclasts than did the control 1 group (P = 0.036). No significant between-group difference in osteoblast cell or capillary numbers was evident when day 7 and 17 data were compared. CONCLUSION Histologically, LLLT stimulated bone formation, as revealed by analysis after the retention period. LLLT during expansion may accelerate bone healing.

Effectiveness of Palosuran in Bleomycin-Induced Experimental Scleroderma

Systemic sclerosis (SSc) is a disease characterized by skin and internal organ involvement. There is progressive accumulation of extracellular matrix components in the skin and involved organs. Tissue fibrosis is the prominent reason for mortality, and still, there is no satisfactory treatment. The aim of this study was to evaluate the effects of urotensin-II (U-II) antagonist palosuran in an animal model of scleroderma. We also planned to measure U-II, endothelin-1 (ET-1), and transforming growth factor-β1 (TGF-β1) levels, as well as the association of these levels with dermal thickness. Twenty-four male mice were included in this study and they were divided into three groups—group 1: control group, group 2: fibrosis group, and group 3: fibrosis + palosuran treatment group. Fibrosis + palosuran treatment in group 3 reduced ET-1, U-II, and TGF-β1 levels. In total, the diminished values were statistically significant in the ET-1 and TGF-β1 levels (p < 0.05). Dermal thickness was higher in the fibrosis group, when compared with the other groups. There was no significant relationship between dermal thickness and ET-1, U-II, or TGF-β1 levels (p > 0.05). It is believed that U-II is an important mediator in SSc, and its antagonism with palosuran could be a new treatment choice in SSc.

Relationship of fibroblast growth factor 21, sirtuin 1, visfatin, and regulators in children with short stature

Abstract Fibroblast growth factor 21 (FGF21) is mainly secreted by the liver. It is a factor that is not fully understood in relation to growth. Sirtuin 1 (SIRT1) is a deacetylase protein. It is thought that may have an effect on the release and function of GH and IGF-1. Visfatin is synthesized from adipose tissue as primary. It may be prognostic marker associated with growth factors. As a result of our work, FGF21 is not associated with short stature but levels of SIRT1 and visfatin are associated with short stature. The decrease in visfatin value in the short-stature group is thought to be due to an insufficient amount of adipose tissue, which is important for growth and development. SIRT1 might decrease GH effect by increasing STAT5 deacetylation in the liver and we think that the result of this reduction of SIRT1 would negatively impact IGF-1 and IGFBP-3 production.

The effects of bupivacaine combined with different adjuvants on block onset and duration and on ion channel expressions (SCN9A, TRPM) in sciatic nerve block in rats

BACKGROUND/AIM The objective of this experimental study was to examine the effects of epinephrine, dexmedetomidine, and clonidine added as adjuvants to bupivacaine on block onset and effect times, as well as the effects on the Na+ and Ca+2 channel gene expressions, which may indicate cell damage in the sciatic nerve cell membrane. MATERIALS AND METHODS Rats were divided into five groups: Group S (sham), saline solution; Group B, bupivacaine; Group BD, bupivacaine + dexmedetomidine; Group BC, bupivacaine + clonidine; and Group BE, bupivacaine + epinephrine. For each group, 0.2 mL of local anesthetic was injected into the sciatic nerve bifurcation point of the right leg. Sensory (proprioceptive and nociceptive block) and motor block onset and ending times were recorded. RESULTS The shortest onset time for the examined sciatic block was observed in the BC group, whereas the longest sensory and motor block times were observed in the BD group. The present data suggest suppressed TRPM7 and increased TRPM2 in the groups other than the BE group. CONCLUSION Clonidine is more suitable for fast onset of peripheral nerve blocks, whereas the addition of dexmedetomidine is better in terms of duration. Because the SCN9A and TRPM2,4,7 expression ratios of the BE group showed the least amount of change, this group had the best cellular integrity.

Investigation of the Esophageal Rho-kinase Expression in Patients with Barrett’s Esophagus

Abstract The mechanisms responsible for the malignant transformation in Barrett’s esophagus (BE) are still poorly understood. The authors have evaluated the role of Rho-kinase (ROCK1 and ROCK2) expressions in patients with BE. All patients underwent upper gastrointestinal system endoscopy, which was confirmed histologically. Real-time PCR revealed no marked change in gene expressions of ROCK1 and ROCK2 at mRNA levels in BE when compared to controls. Immunohistochemical and western blot analyses showed no change in ROCK1 and ROCK2 protein expressions in BE. This study demonstrates that Rho-kinase gene and protein expressions are not modified in BE.