Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Trabecular Meshwork”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,549 records · Page 86Linked to original sources
PubMed1984

[Perilenticular tissue changes in intraocular lenses worn without complications].

Eighteen eyes containing an intraocular lens (IOL) removed post mortem from 16 patients after an uncomplicated postoperative course of up to 50 months, and 2 IOLs removed intraoperatively were studied macroscopically, histologically and ultrastructurally to detect changes in the lenses themselves and in the surrounding ocular tissues. Various types of lens-loop degradation, erosion of the iris pigment epithelium with formation of posterior synechiae and pressure atrophy of the iris stroma were found, but there was little evidence of iritis. A mixed cell population containing many foreign-body giant cells had settled on most lenses, some of which were encased in membranes. The loops of one Sinskey PCL had penetrated the ciliary body and iris root to reach the trabecular meshwork. The significance of these findings is discussed.

Cataract Extraction↗
PubMed1982

[Riegers' anomaly with signs of hydrophthalmia and spontaneous pressure regulation].

Several members of two families with Rieger's anomaly were found to have signs of hydrophthalmia (enlarged corneas, Descemet ruptures, optic disc damage). Two of them revealed normal intraocular pressures during later life without medical or operative treatment. Obviously a spontaneous pressure regulation had occurred. A delayed differentiation of the trabecular meshwork is possibly the cause of self-regulation in these two cases of Rieger's anomaly as in case with congenital glaucoma.

Adolescent↗
PubMed1976

Blood-aqueous barrier can be circumvented by lowering intraocular pressure.

Rhesus monkeys were injected intravenously with hypertonic urea (9 ml/kg body weight of 30% urea in 10% invert sugar) and the intraocular pressure was measured with an applamatic tonometer. When this pressure reached its minimum (20% of the normal value) horseradish peroxidase (molecular weight 40,000; radius of an equivalent hydrodynamic sphere about 2.5 nm; 0.5 g/kg body weight), was injected intravenously. Twenty minutes following peroxidase administration, either aqueous humor was sampled from the anterior chamber for biochemical determination of peroxidase activity, or one eyeball was enucleated and processed for light and electron microscopic localization of the enzymatic tracer. This experiment showed that: (1) therapeutic doses of hypertonic urea do not cause a breakdown of either the blood-retina or the blood-aqueous barriers; (2) as intraocular pressure decreases, peroxidase-containing blood flows back from the episcleral veins into the Schlemm canal; (3) macromolecules up to the dimensions of horseradish peroxidase leak through the intercellular clefts of the endothelium of the Schlemm canal, permeate the juxtacanalicular connective tissue and trabecular meshwork, and finally enter the anterior chamber. Thus, blood-borne substances can circumvent the blood-aqueous barrier when intraocular pressure is decreased, and administration of a hypertonic agent may represent a simple pharmacological device to cause penetration into the ocular chambers by drugs that are normally excluded from the interior of the eye.

Animals↗
PubMed2002

A multidomain TIGR/olfactomedin protein family with conserved structural similarity in the N-terminal region and conserved motifs in the C-terminal region.

Based on the similarity between the TIGR (trabecular-meshwork inducible glucocorticoid response) (also known as myocilin) and olfactomedin protein families identified throughout the length of the TIGR protein, we have identified more distantly related proteins to determine the elements essential to the function/structure of the TIGR and olfactomedin proteins. Using a sequence walk method and the Shotgun program, we have identified a family including 31 olfactomedin domain-containing sequences. Multiple sequence alignments and secondary structure analyses were used to identify conserved sequence elements. Pairwise identity in the olfactomedin domain ranges from 8 to 64%, with an average pairwise identity of 24%. The N-terminal regions of the proteins fall into two subgroups, one including the TIGR and olfactomedin families and another group of apparently unrelated domains. The TIGR and olfactomedin sequences display conserved motifs including a residual leucine zipper region and maintain a similar secondary structure throughout the N-terminal region. The correlation between conserved elements and disease-associated mutations and apparent polymorphisms in human TIGR was also examined to evaluate the apparent importance of conserved residues to the function/structure of TIGR. Several residues have been identified as essential to the function and/or structure of the human TIGR protein based on their degree of conservation across the family and their implication in the pathogenesis of primary open-angle glaucoma. Additionally, we have identified a group of chitinase sequences containing several of the highly conserved motifs present in the C-terminal region of the olfactomedin domain-containing sequences.

Algorithms↗
PubMed2001

Acute effects of H-7 on ciliary epithelium and corneal endothelium in monkey eyes.

PURPOSE: Topical or intracameral administration of H-7 doubles outflow facility and reduces intraocular pressure in cynomolgus monkeys, by relaxing and expanding the trabecular meshwork (TM) and Schlemm's canal (SC). Since H-7 may have anti-glaucoma potential, we determined its effects on the corneal endothelium and ciliary epithelium for safety considerations. METHODS: Following topical H-7, aqueous humor flow (AHF), corneal endothelial transfer coefficient (k(a)) and anterior chamber (AC) entry of i.v. fluorescein were measured by fluorophotometry; AC aqueous protein concentration ([Protein](AC)) was determined by Lowry assay; and corneal thickness and endothelial cell density and morphology were measured by ultrasonic pachymetry and specular microscopy respectively. Following intracameral H-7, specular and/or light and electron microscopy of the corneal endothelium or ciliary epithelium were performed. RESULTS: Following unilateral topical H-7: (1) AHF and k(a) were essentially unchanged at 0.5--3.0, 3.5--6.0, and 0.5--6.0 hr, with an insignificant increase from 0.5--1.5 hr; (2) [Protein]( AC) was insignificantly increased at 1-1.5 hr but had returned to baseline by 2.5 hr; (3) entry of i.v. fluorescein into aqueous or cornea was modestly and transiently increased; (4) the central cornea thickened significantly at 1--2.5 hr, gradually returning to baseline 2.5 hr after H-7, while peripheral corneal thickness was less affected; (5) corneal endothelial cell borders became indistinct by 1 hr, but cell morphology was recovering by 3--5 hr and had completely returned to normal by 24 hr; (6) corneal endothelial cell density was unchanged at 5--24 hr. Following intracameral H-7, no significant changes were observed in corneal endothelial cell density or morphology by specular microscopy, nor in corneal endothelial or ciliary epithelial morphology by light and electron microscopy. CONCLUSIONS: A facility-effective intracameral dose of H-7 had no discernible structural effect on the corneal endothelium or ciliary epithelium. It is not yet clear whether carefully chosen topical doses of H-7 or analogues can enhance outflow facility without meaningfully affecting the cornea and ciliary processes.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed2002

Human Schlemm's canal cells express the endothelial adherens proteins, VE-cadherin and PECAM-1.

Purpose. The majority of resistance to outflow of aqueous humor resides at or near the inner wall of Schlemm's canal (SC). Transmembrane proteins that contribute to the generation of resistance to aqueous outflow likely participate in junctional complexes between SC cells. The purpose of the present study was to examine the expression of cadherins in SC cells that play a significant role in adherens junction complexes that control permeability of vascular endothelia. Methods. Identification of cadherin subtype mRNAs was examined by hybridization screening of three different SC cDNA libraries and by polymerase chain reaction analysis with degenerate primers. Expression of endothelial adherens proteins, vascular endothelial (VE)-cadherin and platelet endothelial cell adhesion molecule-1 (PECAM-1), was examined by western blot analyses of whole cell lysates prepared from SC and trabecular meshwork cells and by immunofluorescence microscopy of frozen sections of human anterior chambers. As controls, bovine retinal, bovine aortic, human umbilical vein and human iliac vein endothelial cells were examined for VE-cadherin expression. Results. Screens of SC cDNAs revealed abundant expression of N-cadherin and VE-cadherin. Expression of VE-cadherin protein was identified in both inner and outer wall SC cells, appropriately localized to SC intercellular borders and appeared as a single band of approximately 130 kDa by western blot analysis. Specific labeling of PECAM-1 was similar to VE-cadherin and appeared as a single band of approximately 130 kDa by western blot analysis. Conclusions. VE-cadherin and PECAM-1 expression in SC suggests that SC cells are vascular in origin and contain adherens protein likely involved in restricting fluid flow across the inner wall of SC.

Animals↗
PubMed2002

Angle closure: classification, concepts, and the role of ultrasound biomicroscopy in diagnosis and treatment.

The angle closure glaucomas are a diverse group of disorders characterized by mechanical blockage of the trabecular meshwork by the peripheral iris leading to elevated intraocular pressure and glaucoma. Understanding the pathophysiologic mechanisms underlying these disorders is essential for both diagnosis and management. This review covers the anatomy, etiology, classification, and therapy of the various angle closure glaucomas and the role that ultrasound biomicroscopy has played in helping us understand these diseases.

Diagnosis, Differential↗
PubMed2004

Effect of hydrostatic pressure gradients and Na2EDTA on permeability of human Schlemm's canal cell monolayers.

PURPOSE: Elevated intraocular pressure in those with glaucoma appears to be a function of increased resistance to movement of aqueous humor through the conventional outflow pathway. The majority of resistance in both normal and glaucomatous eyes is generated in the region between the juxtacanalicular trabecular meshwork and the inner wall of Schlemm's canal. To accommodate transient elevations in pressure, we hypothesize that conventional outflow increases rapidly due to changes in complexity of intercellular junctions between cells of the inner wall of Schlemm's canal. METHODS: To test this hypothesis we examined specifically the effects of hydrostatic pressure gradients and the calcium chelator, Na2EDTA, on permeability of cultured human Schlemm's canal cell monolayers in isolation. Human Schlemm's Canal cells were isolated, cultured and then seeded onto permeable supports and maintained in culture to allow intercellular junctions to mature. With a minimum net transendothelial electrical resistance of 10 Ohm cm2, cells were placed into an Ussing-type chamber and hydraulic conductivity was calculated from pressure and flow measurements that were continuously recorded. Simultaneously, transendothelial electrical resistance was measured manually at fixed intervals. In parallel experiments, cell margins were monitored in real time by videomicroscopy. RESULTS: During the baseline measurement period when cells were exposed to pressure but not Na2EDTA, hydraulic conductivity was constant but transendothelial electrical resistance decreased continuously at rate of 0.24 Ohm cm2/minute. After Na2EDTA treatment, no significant change in transendothelial electrical resistance was measured while, hydraulic conductivity of Schlemm's Canal monolayers increased significantly by 125%; corresponding to noticeable intercellular separations. Restoration of cell-cell contact was observed by videomicroscopy 30 minutes following washout of Na2EDTA and functionally after 2 hours. CONCLUSIONS: Responses of Schlemm's Canal cells to pressure and calcium chelators in vitro are consistent with a role for calcium sensitive junctions in outflow resistance in vivo.

Animals↗
PubMed2005

Localization of collagen XVIII and endostatin in the human eye.

PURPOSE: To investigate the localization of endostatin, a potent angiogenesis inhibitor, and its progenitor collagen XVIII in the human eye. METHODS: Twelve normal human eyes were investigated. Immunohistochemistry of the anterior and posterior eye segment was performed using a polyclonal endostatin and collagen XVIII antibody and a monoclonal collagen XVIII antibody. Specificity of the antibodies was confirmed by Western blot analysis. RESULTS: The antibody against collagen XVIII stained Bowman's membrane, the lens capsule, the trabecular meshwork, and all epithelial and endothelial basal membranes in the anterior and posterior eye segment. In contrast, the antibody against endostatin showed a more distinct staining pattern. Intense intracellular staining for endostatin was present in the lens epithelium and in the non-pigmented epithelium of the ciliary body. Extracellular presence of endostatin could be detected in the lens capsule and all border membranes lining the aqueous humor including the anterior surface of the iris. The choroid was unstained. In the retina, staining was restricted to the inner limiting membrane and to endothelial cells of larger vessels. CONCLUSIONS: Our results show that there is a ring of specifically endostatin expressing structures forming a "barrier" around the anterior chamber and the vitreous. This might physiologically prevent vessels from sprouting into these avascular compartments.

Adult↗
PubMed2006

Glutathione-related enzymes and the eye.

Glutathione and the related enzymes belong to the defence system protecting the eye against chemical and oxidative stress. This review focuses on GSH and two key enzymes, glutathione reductase and glucose-6-phosphate dehydrogenase in lens, cornea, and retina. Lens contains a high concentration of reduced glutathione, which maintains the thiol groups in the reduced form. These contribute to lens complete transparency as well as to the transparent and refractive properties of the mammalian cornea, which are essential for proper image formation on the retina. In cornea, gluthatione also plays an important role in maintaining normal hydration level, and in protecting cellular membrane integrity. In retina, glutathione is distributed in the different types of retinal cells. Intracellular enzyme, glutathione reductase, involved in reducing the oxidized glutathione has been found at highest activity in human and primate lenses, as compared to other species. Besides the enzymes directly involved in maintaining the normal redox status of the cell, glucose-6-phosphate dehydrogenase which catalyzes the first reaction of the pentose phosphate pathway, plays a key role in protection of the eye against reactive oxygen species. Cornea has a high activity of the pentose phosphate pathway and glucose-6-phosphate dehydrogenase activity. Glycation, the non-enzymic reaction between a free amino group in proteins and a reducing sugar, slowly inactivates gluthathione-related and other enzymes. In addition, glutathione can be also glycated. The presence of glutathione, and of the related enzymes has been also reported in other parts of the eye, such as ciliary body and trabecular meshwork, suggesting that the same enzyme systems are present in all tissues of the eye to generate NADPH and to maintain gluthatione in the reduced form. Changes of glutathione and related enzymes activity in lens, cornea, retina and other eye tissues, occur with ageing, cataract, diabetes, irradiation and administration of some drugs.

Animals↗
PubMed1998

Histochemical mapping of NADPH-diaphorase in monkey and human eyes.

PURPOSE: To localize nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) in normal human and monkey eyes. METHODS: NADPH-d activity in ocular tissue sections was revealed by histochemical staining. RESULTS: NADPH-d staining was found in the anterior and posterior ocular segment of both species. In the anterior segment, reaction product was present in the corneal epithelium and endothelium, iris dilator and sphincter, lens capsule, ciliary muscle, and non-pigmented epithelial cells and stroma of the ciliary processes. Staining density in the longitudinal ciliary muscle was higher than in the other ciliary muscle regions in the human; such regionalization was less apparent in the monkey. The trabecular meshwork stained minimally if at all in both species. In the posterior segment, staining was seen around choroidal blood vessels and choroidal nerves, and in the retinal pigment epithelial, photoreceptor, bipolar, inner plexiform and ganglion cell layers. CONCLUSIONS: NADPH-d is widespread in human and monkey eyes, indicating significant and presumably functionally relevant NO production in the various ocular structures.

Adolescent↗
PubMed2006

Physiological significance and expression of P450s in the developing eye.

Expression of 10 CYP orthologs (Families 1-3) in developing mouse conceptus is constitutive. These forms have specific temporal and spatial expression. Studies on CYP1B1 indicate its requirement for normal eye development, both in human and mouse. The distribution of the enzyme in the mouse eye is in three regions, which may reflect three different, perhaps equally important, functions in this organ. Its presence in the inner ciliary and lens epithelia appears to be necessary for normal development of the trabecular meshwork and its function in regulating intraocular pressure. Its expression in the retinal ganglion and inner nuclear layers may reflect a role in maintenance of the visual cycle. Its expression in the corneal epithelium may indicate a function in metabolism of environmental xenobiotics.

Animals↗
PubMedDate not supplied

Fuchs' heterochromic cyclitis.

Fuchs' heterochromic cyclitis (FHC) is a chronic anterior segment inflammatory syndrome that accounts for 2 to 3% of all uveitis cases. The etiology is unknown, but Herpes simplex, ocular toxoplasmosis and rubella infection have been implicated in the pathogenesis of the disease. It occurs more commonly in the third and fourth decades of life with an equal gender distribution. Patients are usually asymptomatic but may present with floaters and blurry vision. There is a mild but persistent anterior chamber reaction with diffuse and characteristic white stellate keratic precipitates. Iris and trabecular meshwork show abnormal vessels that may sometimes lead to a hyphema. Synechia formation is uncommon. Heterochromia is considered an important feature and accounts for the name, but it is variable depending on the intensity of the anterior stromal atrophy, initial iris color and amount of pigment in the iris pigmented epithelium. Progression of the disease is associated with cataract formation and glaucoma. Anti-inflammatory treatment is not indicated for the low-grade anterior chamber reaction seen in Fuchs' patients. Occasionally, a short course of corticosteroids is indicated if a symptomatic exacerbation occurs. The long-term prognosis is good, and patients usually maintain a visual acuity of 20/40 or better.

Humans↗
PubMedDate not supplied

Cellular immunohistochemical localization of the matricellular protein myocilin in the intervertebral disc.

Myocilin is a 55-57-kDa protein that is a member of the olfactomedin protein family. It is expressed in the cornea, sclera and trabecular network of the eye, myelinated peripheral nerves, heart, skeletal muscle, trachea and other tissues. Myocilin binds to a domain of fibronectin, type IV collagen and laminen in the trabecular meshwork of the eye, and its expression is influenced by transforming growth factor beta. Because these extracellular matrix components also are common in the intervertebral disc, the objective of our study was to determine whether the matricellular protein myocilin could be detected in the human or sand rat intervertebral disc using immunohistochemistry and to assess its localization. We investigated 16 specimens of human disc tissue and discs from six sand rats. Three human disc cell cultures grown in three-dimensional culture also were evaluated. Immunocytochemical annulus analysis showed the presence of myocilin within the disc cell cytoplasm in some, but not all, cells. Extracellular matrix in both the human and sand rat disc was negative for myocilin localization. Myocilin is believed to play a role in cell-cell adhesion and/or signaling. Myocilin may have such functions within the disc cell population in a manner similar to tenascin, SPARC and thrombospondin, which are other matricellular proteins recently shown to be present in the disc.

Adult↗
PubMed2002

Aquaporin deletion in mice reduces intraocular pressure and aqueous fluid production.

Aquaporin (AQP) water channels are expressed in the eye at sites of aqueous fluid production and outflow: AQP1 and AQP4 in nonpigmented ciliary epithelium, and AQP1 in trabecular meshwork endothelium. Novel methods were developed to compare aqueous fluid dynamics in wild-type mice versus mice lacking AQP1 and/or AQP4. Aqueous fluid production was measured by in vivo confocal microscopy after transcorneal iontophoretic introduction of fluorescein. Intraocular pressure (IOP), outflow, and anterior chamber compliance were determined from pressure measurements in response to fluid infusions using micropipettes. Aqueous fluid volume and [Cl(-)] were assayed in samples withdrawn by micropipettes. In wild-type mice (CD1 genetic background, age 4-6 wk), IOP was 16.0 +/- 0.4 mmHg (SE), aqueous fluid volume 7.2 +/- 0.3 microl, fluid production 3.6 +/- 0.2 microl/h, fluid outflow 0.36 +/- 0.06 microl/h/mmHg, and compliance 0.036 +/- 0.006 microl/mmHg. IOP was significantly decreased by up to 1.8 mmHg (P < 0.002) and fluid production by up to 0.9 microl/h in age/litter-matched mice lacking AQP1 and/or AQP4 (outbred CD1 and inbred C57/bl6 genetic backgrounds). However, AQP deletion did not significantly affect outflow, [Cl(-)], volume, or compliance. These results provide evidence for the involvement of AQPs in intraocular pressure regulation by facilitating aqueous fluid secretion across the ciliary epithelium. AQP inhibition may thus provide a novel approach for the treatment of elevated IOP.

Animals↗
PubMed2001

Inhibition of angiogenesis by adenovirus-mediated sFlt-1 expression in a rat model of corneal neovascularization.

Pathological angiogenesis, or the production of new capillary vessels from preexisting vasculature, within the eye is a serious event that often leads to blindness. Upregulation of vascular endothelial growth factor (VEGF) has been linked to neovascularization in the eye, suggesting that it could be a suitable target to inhibit angiogenic changes. This work investigated whether the presence of a proven antiangiogenic factor, the soluble variant of the VEGF receptor, sFlt-1, in the anterior chamber is sufficient to inhibit new vessel formation in the cornea in an animal model of corneal neovascularization. A recombinant adenovirus vector that can mediate efficient in vivo gene transfer and expression in ocular cells was selected as a delivery agent. We have shown that after the injection of Ad.betagal into the anterior chamber of normal and cauterized rat eyes, corneal endothelial cells and cells of the trabecular meshwork were efficiently transduced and that beta-galactosidase (beta-Gal) expression was maintained up to 10 days postinjection. Cauterization significantly increased the amount of immunoreactive VEGF in vehicle- or Ad.null-injected animals (t test, p < 0.001 and p < 0.001, respectively). However, when cauterization was combined with Ad.sflt injection there was no statistically significant increase in the amount of immunoreactive VEGF (p = 0.12). The injection of Ad.sflt into the anterior chamber slowed or inhibited VEGF-induced angiogenic changes. After cauterization, 100% of uninjected and vehicle-injected and 82% of Ad.null-injected animals developed moderate to severe corneal angiogenesis in contrast to 18% of Ad.sflt-injected animals. These in vivo results suggest that the transient presence of antiangiogenic agents in the anterior chamber can be successfully used to inhibit the development of corneal angiogenesis.

Adenoviridae↗
PubMed2001

Effects of protein tyrosine kinase inhibitor genistein on retinal function in superfused vertebrate retina.

The aim of this study was to evaluate safe concentrations of genistein for a potential intraocular application using the isolated retina technique on bovine retina preparations. Bovine retinas were isolated and perfused with an oxygen pre-equilibrated standard solution. The electroretinogram (ERG) was recorded as a transretinal potential using silver/silver-chloride electrodes. After recording of stable ERG amplitudes, genistein was added to the solution in different concentrations. The percentage of b-wave reduction under the drug was calculated. We also studied the influence of genistein on the a-wave amplitude. After the addition of aspartate, the b-wave amplitude was reduced continuously until unmasked a-wave amplitudes were reached. Genistein was then added to the aspartate containing perfusate. The percentage of a-wave amplitude reduction under the drug was calculated. Concentrations of 3.3 microMol/l and higher were found to reduce the b-wave amplitude. The a-wave amplitude was not changed by the applied concentrations. The ERG only showed toxic effects from genistein beyond concentrations that were found to inhibit endothelial cell growth in vitro. In previous studies, beneficial effects on trabecular meshwork cells were present for genistein concentrations which are distinctly higher than the maximum nontoxic concentration reported here. It was shown that the photoreceptor layer is not affected at the examined concentration range. Therefore, we attribute the toxic effects to postsynaptic interaction of genistein. Intraocular application of genistein in a sufficient concentration seems possible.

Animals↗
PubMed2003

Effects of prostaglandin F2alpha and latanoprost on phosphoinositide turnover, myosin light chain phosphorylation and contraction in cat iris sphincter.

The effects of the ocular hypotensive agents prostaglandin F(2alpha) (PGF(2alpha)) and its analog latanoprost on intraocular pressure (IOP) in both animals and human have been investigated extensively in the last two decades. While there is general agreement that application of these PGs to the eye alters IOP by altering the aqueous humor outflow of the eye via the uveoscleral and trabecular meshwork pathways, the mechanism of action of these agents on IOP lowering remains unclear. There is evidence which suggests that myosin light kinase (MLC kinase) may be involved in the IOP-lowering effects of these agents. Thus, the purpose of the present work was to investigate in cat iris sphincter the effects of these PGs on the MLC kinase signaling pathway, inositol phosphates production, MLC phosphorylation and contraction, in order to gain more information about the mechanism through which these agents modulate smooth muscle function and lower IOP. [(3)H]myo-inositol phosphates production was measured by ion-exchange chromatography, MLC kinase activity was measured by incorporation of (32)Pi into MLC, and changes in muscle tension were recorded isometrically. PGF(2alpha) and latanoprost induced contraction in a concentration-dependent manner with EC(50) values of 18.6 and 29.9 nM, respectively, and increased inositol phosphates production in a concentration-dependent manner. At 1 microM, PGF(2alpha) and latanoprost increased inositol phosphates formation by 125 and 102% over basal, respectively. PGF(2alpha) and latanoprost increased MLC phosphorylation in a concentration- and time-dependent manner, at 1 microM and 5 min incubation, the PGs increased the MLC response by 181 and 176% over basal, respectively. In general, PGF(2alpha) was slightly more potent in inducing the biochemical and pharmacological responses. Wortmannin, ML-7 and ML-9, selective inhibitors of MLC kinase, inhibited significantly PGF(2alpha)- and latanoprost-induced MLC phosphorylation and contraction. These results demonstrate for the first time involvement of the MLC kinase pathway in the FP receptor function of this ocular tissue. Contraction-relaxation of smooth muscle alters the shape and stiffness of smooth muscle cells and MLC kinase, through myosin phosphorylation and dephosphorylation, has been shown to be involved in cytoskeletal remodeling, cytoskeletal alterations, and IOP lowering. In light of these reports and the findings presented here we suggest that alterations in the MLC kinase signaling pathway and its derived second messengers, which leads to changes in contraction-relaxation of the smooth muscles of the anterior segment, could facilitate aqueous humor outflow and thus contribute to the IOP-lowering effects of the FP-class PGs.

Animals↗