Purpose: To determine the effects of injection of the protein kinase C (PKC) activator phorbol 12-myristate 13-acetate (PMA) into the anterior chamber of the eye on intraocular pressure (IOP) and aqueous humor dynamics.
Methods: IOP was measured for 24 h after intracameral injection of PMA (3 to 50 pmol) in unanesthetized rabbits. Aqueous humor dynamics (aqueous flow, total outflow facility, and uveoscleral outflow) were determined approximately 6 h after injection of 50 pmol of PMA in animals pretreated with indomethacin.
Results: Intracameral injection of 50 pmol of PMA induced a biphasic effect on IOP, consisting of a transient increase apparent at 0.5 and 1 h and a sustained decrease apparent after 2 h. This effect of PMA was dose dependent. Whereas pretreatment with indomethacin attenuated the PMA-induced increase in IOP, the sustained decrease in IOP remained apparent in the pretreated rabbits. Intracameral injection of 4alpha-PMA, an inactive PMA analog, had no effect on IOP. PMA also significantly increased uveoscleral outflow, but it had no effect on aqueous flow or total outflow facility.
Conclusion: Intracameral injection of PMA reduced IOP in the rabbits by increasing the rate of uveoscleral outflow. This IOP-lowering effect of PMA may be mediated by activation of PKC.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s10384-006-0365-6 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Travoprost Intracameral Implant in Eyes with Glaucoma or Ocular Hypertension: Early Short-Term Real-World Outcomes.
Clin Ophthalmol
January 2025
Harvard Eye Associates, Laguna Hills, CA, USA.
Purpose: To assess real-world efficacy and safety of standalone travoprost intracameral implant (iDose TR) implantation by a US glaucoma surgeon in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).
Methods: This non-randomized, retrospective, unmasked, consecutive case series included all cases of standalone iDose TR implantation from a single US glaucoma surgeon since the product's approval by the US Food and Drug Administration (FDA) in December 2023. Patients were pseudophakic, had OAG or OHT, and had undergone prior SLT and/or bimatoprost intracameral implant injection (Durysta).
Effect of intracameral air injection during Ahmed glaucoma valve implantation on hypertensive phase.
Sci Rep
January 2025
Horang-i Eye Clinic, Seoul, South Korea.
The purpose of this study was to evaluate the difference in the incidence of the hypertensive phase (HP) between Ahmed glaucoma valve (AGV) patients who received intracameral air injection and those who did not. A total of 78 patients who underwent AGV surgery between January 1, 2016 and June 30, 2023 were included in this retrospective study. HP was defined as intraocular pressure (IOP) greater than 21 mmHg within the first 6 postoperative months.
View Article and Find Full Text PDFTubulin Acetylation Enhances Microtubule Stability in Trabecular Meshwork Cells Under Mechanical Stress.
Invest Ophthalmol Vis Sci
January 2025
Department of Ophthalmology, Duke Eye Center, Duke University, Durham, North Carolina, United States.
Purpose: To study the roles of tubulin acetylation and cyclic mechanical stretch (CMS) in trabecular meshwork (TM) cells and their impact on outflow pathway physiology and pathology.
Methods: Primary TM cell cultures were subjected to CMS (8% elongation, 24 hours), and acetylated α-tubulin at lysine 40 (Ac-TUBA4) was assessed by western blotting and immunofluorescence. Enzymes regulating tubulin acetylation were identified via siRNA-mediated knockdowns of ATAT1, HDAC6, and SIRT2.
Repair of Descemet's membrane detachment following inadvertent intrastromal viscoelastic injection for hypotony: anterior and posterior approaches.
BMJ Case Rep
January 2025
Department of Ophthalmology, Royal Free London NHS Foundation Trust, London, UK
Descemet's membrane (DM) detachment is a significant, if rare, risk of intracameral injection of viscoelastic to treat hypotony after glaucoma filtration surgery. We describe two cases of DM detachment following inadvertent injection of viscoelastic into the posterior stroma and the techniques used for their repair. In both cases, conventional air tamponade failed to resolve the detachment, and further surgical intervention was required.
View Article and Find Full Text PDFMefunidone Inhibits Inflammation, Oxidative Stress, and Epithelial-Mesenchymal Transition in Lens Epithelial Cells.
Invest Ophthalmol Vis Sci
December 2024
Eye Center of Xiangya Hospital, Central South University, Changsha, China.
Purpose: Inflammation, oxidative stress, and epithelial-mesenchymal transition (EMT) play crucial roles in forming posterior capsular opacification (PCO), particularly in fibrotic PCO. Here we investigated the protective effects of mefunidone (MFD), a novel compound with potent antifibrotic properties, which could be useful in preventing PCO.
Methods: We utilized an extracapsular lens extraction (ECLE) surgery in mice to simulate the development of PCO in vivo.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!