scholarly journals L-type calcium channel blocker increases VEGF concentrations in retinal cells and human serum

2021 ◽  
Author(s):  
Anmol Kumar ◽  
Stefan Mutter ◽  
Erika Parente ◽  
Valma Harjutsalo ◽  
Raija Lithovius ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Human Serum ◽  
Channel Blocker ◽  
Channel Blockers ◽  
Vascular Endothelial ◽  
Retinal Cells ◽  
Diabetic Eye Disease ◽  
Design And Methods ◽  
Endothelial Growth Factor

Objective: Vascular endothelial growth factor (VEGF) plays a key role in diabetic retinopathy (DR). L-type calcium channel blockers (LTCCBs) have been widely used as antihypertensive medication (AHM), but their association with VEGF and DR is still unclear. Therefore, we explored the effect of LTCCBs compared to other AHMs on VEGF concentrations in retinal cells and human serum. Furthermore, we evaluated the association between the use of LTCCBs and the risk of severe diabetic eye disease (SDED). Research design and methods: Muller cells (MIO-M1) were cultured as per recommended protocol and treated with LTCCBs and other AHMs. VEGF secreted from cells were collected at 24 hours intervals. In an interventional study, 39 individuals received LTCCBs or other AHM for four weeks with a four-week wash-out placebo period between treatments. VEGF was measured during the medication and placebo periods. Finally, we evaluated the risk of SDED associated with LTCCB usage in 192 individuals from the FinnDiane Study in an oberservational setting. Results: In the cell cultures, medium VEGF concentration increased time-dependently after amlodipine (p<0.01) treatment, but not after losartan (p>0.01), or lisinopril (p>0.01). Amlodipine, but no other AHM, increased serum VEGF concentration (p<0.05) during the interventional clinical study. The usage of LTCCB was not associated with the risk of SDED in the observational study. Conclusions: LTCCB increases VEGF concentrations in retinal cells and human serum. However, the usage of LTCCBs does not appear to be associated with SDED in adults with type 1 diabetes.

Electroanalytical Methods for Determination of Calcium Channel Blockers

2019 ◽  
Vol 15 (3) ◽  
pp. 207-218 ◽  
Author(s):  
Fatma Ağın
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Channel Blocker ◽  
Heart Diseases ◽  
Dosage Forms ◽  
Channel Blockers ◽  
Electroanalytical Methods ◽  
Pharmaceutical Dosage Forms ◽  
Ischemic Heart Diseases

Background:Calcium Channel Blockers (CCBs) are widely used in the treatment of cardiovascular and ischemic heart diseases in recent years. They treat arrhythmias by reducing cardiac cycle contraction and also benefit ischemic heart diseases. Electroanalytical methods are very powerful analytical methods used in the pharmaceutical industry because of the determination of therapeutic agents and/or their metabolites in clinical samples at extremely low concentrations (10-50 ng/ml). The purpose of this review is to gather electroanalytical methods used for the determination of calcium channel blocker drugs in pharmaceutical dosage forms and biological media selected mainly from current articles.Methods:This review mainly includes recent determination studies of calcium channel blockers by electroanalytical methods from pharmaceutical dosage forms and biological samples. The studies of calcium channel blockers electroanalytical determination in the literature were reviewed and interpreted.Results:There are a lot of studies on amlodipine and nifedipine, but the number of studies on benidipine, cilnidipine, felodipine, isradipine, lercanidipine, lacidipine, levamlodipine, manidipine, nicardipine, nilvadipine, nimodipine, nisoldipine, nitrendipine, diltiazem, and verapamil are limited in the literature. In these studies, DPV and SWV are the most used methods. The other methods were used less for the determination of calcium channel blocker drugs.Conclusion:Electroanalytical methods especially voltammetric methods supply reproducible and reliable results for the analysis of the analyte. These methods are simple, more sensitive, rapid and inexpensive compared to the usually used spectroscopic and chromatographic methods.

scholarly journals Myopic foveal detachment associated with pachychoroid characteristics

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yong Kyun Shin ◽  
Sun Hyup Han ◽  
Se Woong Kang ◽  
Sang Jin Kim ◽  
A Young Kim
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Multimodal Imaging ◽  
High Myopia ◽  
Complete Response ◽  
Response To Treatment ◽  
Vascular Endothelial ◽  
Foveal Detachment ◽  
Endothelial Growth Factor ◽  
Choroidal Vascular Hyperpermeability

Abstract Purpose To describe myopic nontractional foveal detachment associated with pachychoroid diseases. Methods This retrospective study included 15 myopic eyes which had nontractional serous foveal detachment. The eyes were divided into myopic central serous chorioretinopathy (CSC) group (n = 8) and a myopic pachychoroid neovascularization (PNV) group (n = 7) according to the presence of type 1 choroidal neovascularization on multimodal imaging. The findings of multimodal imaging and treatment response were described. Results In myopic CSC group, pachychoroid features such as pachyvessels, choroidal vascular hyperpermeability and punctate hyperfluorescent spots were noted in 8 eyes (100%), 8 eyes (100%), 5 eyes (62.5%) respectively. The above features were noted in 7 eyes (100%), 5 eyes (83.3%), 5 eyes (83.3%), respectively, in the myopic PNV group. Five of 8 eyes in myopic CSC and all 7 eyes received treatment including anti-vascular endothelial growth factor injection and/or photodynamic therapy. However, only five eyes had a complete response. Conclusions The pachychoroid phenotype may coexist with high myopia and lead to myopic nontractional serous foveal detachment. Our series suggest that the response to treatment for these conditions would be limited.

Systemic conbercept pharmacokinetics and VEGF pharmacodynamics following intravitreal injections of conbercept in patients with retinopathy of prematurity

2021 ◽  
pp. bjophthalmol-2021-319131
Author(s):  
Yong Cheng ◽  
Shuang Sun ◽  
Xun Deng ◽  
Xuemei Zhu ◽  
Dandan Linghu ◽  
...  
Keyword(s):  
Retinopathy Of Prematurity ◽  
Intravitreal Injections ◽  
Vascular Endothelial ◽  
Randomised Study ◽  
Limit Of Quantitation ◽  
Significant Difference ◽  
Endothelial Growth Factor ◽  
Type 1 Rop

BackgroundData on serum vascular endothelial growth factor (VEGF) and drug levels in patients with retinopathy of prematurity (ROP) following intravitreal injections of conbercept (IVC) are lacking.MethodsMulticentre, prospective, non-randomised study of patients with aggressive posterior retinopathy of prematurity (APROP) or type 1 ROP who had not received other treatment. All infants received therapy in both eyes plus intravitreal IVC 0.25 mg/0.025 mL in one eye and had at least 6 months of follow-up. Blood samples were collected before and 1 week and 4 weeks after IVC. The main outcome measures were serum conbercept and VEGF concentrations.ResultsForty infants with APROP or type 1 ROP were enrolled. The mean serum VEGF at baseline and 1 week and 4 weeks after a total of 0.25 mg of IVC was 953.35±311.90 pg/mL, 303.46±181.89 pg/mL and 883.12±303.89 pg/mL, respectively. Serum VEGF 1 week after IVC was significantly lower (p<0.05) than baseline, and at 4 weeks after IVC, it was significantly higher (p<0.05) than at 1 week. There was no significant difference (p>0.05) between baseline and 4 weeks. Serum conbercept was below the limit of quantitation (BLOQ) at baseline and 4 weeks and was 19.81±7.60 ng/mL at 1 week.ConclusionSerum VEGF 1 week after IVC was significantly lower than baseline but returned to baseline at 4 weeks. Serum conbercept increased at 1 week and was BLOQ at 4 weeks.

scholarly journals Des(1–3)IGF-1 Treatment Normalizes Type 1 IGF Receptor and Phospho-Akt (Thr 308) Immunoreactivity in Predegenerative Retina of Diabetic Rats

2003 ◽  
Vol 4 (1) ◽  
pp. 45-57 ◽  
Author(s):  
A. Kummer ◽  
B. E. Pulford ◽  
D. N. Ishii ◽  
G. M. Seigel
Keyword(s):  
Growth Factor ◽  
Ganglion Cell Layer ◽  
Systemic Treatment ◽  
Diabetic Rats ◽  
Vascular Endothelial ◽  
Diabetic Retina ◽  
Igf Receptor ◽  
Endothelial Growth Factor ◽  
Biochemical Abnormalities

Little is known about interventions that may prevent predegenerative changes in the diabetic retina. This study tested the hypothesis that immediate, systemic treatment with an insulin-like growth factor (IGF)-1 analog can prevent abnormal accumulations of type 1 IGF receptor, and phospho-Akt (Thr 308) immunoreactivity in predegenerative retinas of streptozotocin (STZ) diabetic rats. Type 1 IGF receptor immunoreactivity increased approximately 3-fold in both inner nuclear layer (INL) and ganglion cell layer (GCL) in retinas from STZ rats versus nondiabetic controls. Phospho-Akt (Thr 308) immunoreactivity increased 5-fold in GCL and 8-fold in INL of STZ rat retinas. In all cases, immunoreactive cells were significantly reduced in STZ des(1–3)IGF-1–treated versus STZ rats. Preliminary results suggested that vascular endothelial growth factor (VEGF) levels may also be reduced. Hyperglycemia/ failure of weight gain in diabetic rats continued despite systemic des(1–3)IGF-1. These data show that an IGF-1 analog can prevent early retinal biochemical abnormalities implicated in the progression of diabetic retinopathy, despite ongoing hyperglycemia.

Influence of Nifedipine on the Visual Fields of Patients with Optic-Nerve-Head Diseases

1994 ◽  
Vol 4 (1) ◽  
pp. 24-28 ◽  
Author(s):  
A.Z. Gaspar ◽  
J. Flammer ◽  
PH. Hendrickson
Keyword(s):  
Optic Nerve ◽  
Visual Field ◽  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Optic Nerve Head ◽  
Channel Blocker ◽  
Glaucoma Patient ◽  
Visual Fields ◽  
Visual Field Defects ◽  
Channel Blockers

Calcium-channel blockers have long been employed in coronary disease, and recent investigations have indicated their efficacy in improving the visual field in low-tension glaucoma or presumed vasospasm, possibly by enhancing ocular circulation. We evaluated the short-term influence of a typical calcium-channel blocker, nifedipine, on 59 patients with visual-field defects, some with optic-nerve-head pathology (n = 38) and some with normal-appearing optic nerve heads (n = 21). On the average, a statistically significant improvement of 1.2 dB was observed. Different types of patients, however, behaved quite differently. The younger the patient, the greater the improvement. Patients with normal optic nerve heads improved by 1.54 dB, whereas patients with optic-nerve-head excavation improved by only 0.66 dB. No response was observed in patients with anterior ischemic neuropathy. Marked deterioration was noted in one glaucoma patient with low systemic blood pressure. The visual-field changes were observed in the scotomatous and non-scotomatous areas. Thus, the calcium-channel blocker nifedipine can be effective in some selected diseases whose pathogenesis probably involves vascular dysregulation though it may even be contraindicated in others

scholarly journals Aberrant Exon 8/8a Splicing by Downregulated PTBP (Polypyrimidine Tract-Binding Protein) 1 Increases Ca V 1.2 Dihydropyridine Resistance to Attenuate Vasodilation

2020 ◽  
Vol 40 (10) ◽  
pp. 2440-2453
Author(s):  
Jianzhen Lei ◽  
Xiaoxin Liu ◽  
Miaomiao Song ◽  
Yingying Zhou ◽  
Jia Fan ◽  
...  
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blocker ◽  
Channel Blocker ◽  
Binding Protein ◽  
Expression Patterns ◽  
Mesenteric Arteries ◽  
Channel Blockers ◽  
Polypyrimidine Tract ◽  
Polypyrimidine Tract Binding ◽  
Polypyrimidine Tract Binding Protein

Objective: Calcium channel blockers, such as dihydropyridines, are commonly used to inhibit enhanced activity of vascular Ca V 1.2 channels in hypertension. However, patients who are insensitive to such treatments develop calcium channel blocker-resistant hypertension. The function of Ca V 1.2 channel is diversified by alternative splicing, and the splicing factor PTBP (polypyrimidine tract-binding protein) 1 influences the utilization of mutually exclusive exon 8/8a of the Ca V 1.2 channel during neuronal development. Nevertheless, whether and how PTBP1 makes a role in the calcium channel blocker sensitivity of vascular Ca V 1.2 channels, and calcium channel blocker-induced vasodilation remains unknown. Approach and Results: We detected high expression of PTBP1 and, inversely, low expression of exon 8a in Ca V 1.2 channels (Ca V 1.2 E8a ) in rat arteries. In contrast, the opposite expression patterns were observed in brain and heart tissues. In comparison to normotensive rats, the expressions of PTBP1 and Ca V 1.2 E8a channels were dysregulated in mesenteric arteries of hypertensive rats. Notably, PTBP1 expression was significantly downregulated, and Ca V 1.2 E8a channels were aberrantly increased in dihydropyridine-resistant arteries compared with dihydropyridine-sensitive arteries of rats and human. In rat vascular smooth muscle cells, PTBP1 knockdown resulted in shifting of Ca V 1.2 exon 8 to 8a. Using patch-clamp recordings, we demonstrated a concomitant reduction of sensitivity of Ca V 1.2 channels to nifedipine, due to the higher expression of Ca V 1.2 E8a isoform. In vascular myography experiments, small interfering RNA-mediated knockdown of PTBP1 attenuated nifedipine-induced vasodilation of rat mesenteric arteries. Conclusions: PTBP1 finely modulates the sensitivities of Ca V 1.2 channels to dihydropyridine by shifting the utilization of exon 8/8a and resulting in changes of responses in dihydropyridine-induced vasodilation.

scholarly journals Anti-Vascular Endothelial Growth Factor Therapy for Primary Treatment of Type 1 Retinopathy of Prematurity

Ophthalmology ◽  
2017 ◽  
Vol 124 (5) ◽  
pp. 619-633 ◽  
Author(s):  
Deborah K. VanderVeen ◽  
Michele Melia ◽  
Michael B. Yang ◽  
Amy K. Hutchinson ◽  
Lorri B. Wilson ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Retinopathy Of Prematurity ◽  
Primary Treatment ◽  
Vascular Endothelial ◽  
Factor Therapy ◽  
Growth Factor Therapy ◽  
Endothelial Growth Factor
Sign in / Sign up

Export Citation Format

Share Document