Evaluation of retinal damage induced by air/fluid exchange using a trypan blue inclusion test in rabbits.

PURPOSE: To investigate whether retina damaged in the process of air/fluid exchange could be visualized in situ using trypan blue staining. METHODS: Vitrectomy and air/fluid exchange with continuous air infusion for various periods of time was performed in adult pigmented rabbits, followed by injection of 0.4% trypan blue solution into the vitreous cavity. Retinal staining was evaluated intraoperatively under the operating microscope and by light microscopy after enucleation. RESULTS: Intraoperative examination showed localized trypan blue staining of areas of the retina opposite the infusion cannula. Light microscopy of the same areas revealed intranuclear trypan blue inclusion in the retina. CONCLUSION: Trypan blue staining allows for the immediate in situ evaluation of damage to the retina associated with air/fluid exchange and continuous air infusion in rabbit eyes.

Effect of rabbit aqueous humor obtained after cataract surgery on collagen gel contraction induced by bovine lens epithelial cells.

We evaluated the effect of specimens of pre- and postoperative aqueous humor on the contraction of collagen gels, and the effect of transforming growth factor-beta(2) (TGF-beta(2)) in postoperative aqueous humor. Rabbit aqueous humor was collected preoperatively and on postoperative day 7. Bovine lens epithelial cells (LECs) were cultured in collagen gel in F-12 nutrient mixture supplemented with 5% fetal bovine serum that contained 10% aqueous humor obtained under various conditions. Gel area was determined on day 4. Gels cultured with the medium that contained phosphate-buffered saline showed a statistically significant contraction after 4 days. Aqueous humor from aphakic or pseudophakic eyes significantly increased contraction, with both specimens having a similar effect. Approximately 60% of the contractile effect of the postoperative aqueous humor was neutralized by anti-TGF-beta(2) antibody. However, the promoting effect of the aqueous humor sampled postoperatively was less than that sampled preoperatively. Although the aqueous humor obtained postoperatively increased the contractility of the LECs, with the level of TGF-beta(2) apparently responsible for much of its effect, the effect was less than that observed in the aqueous humor obtained preoperatively.

Alpha-smooth muscle actin expression in cultured lens epithelial cells.

PURPOSE: Lens epithelial cells transdifferentiate to myofibroblasts during the formation of anterior subcapsular cataracts and secondary cataracts. One of the defining characteristics of myofibroblasts is the expression of alpha-smooth muscle actin (alpha-SMA). This study investigated some of the factors that influence alpha-SMA expression in lens epithelial cells. METHODS: Bovine, rabbit, and human lens epithelial explants or cells were cultured with or without serum. Immunohistochemistry and immunoblotting were used to detect and quantitate alpha-SMA expression. RESULTS: Cells from all species studied expressed alpha-SMA in primary explant culture with or without serum. Immunostaining for alpha-SMA first appeared in a diffuse granular pattern, then accumulated at the cell cortex, and eventually was detected along stress fibers. When lens epithelial cells migrated onto cell-free regions of the capsule or were transferred to a plastic culture dish, alpha-SMA expression increased significantly. Expression of alpha-SMA positively correlated with cell size and cell migration. CONCLUSIONS: Expression of alpha-SMA is a common feature of cultured mammalian lens epithelial cells. Because alpha-SMA expression occurred without the addition of exogenous factors, the fibrosis seen in anterior subcapsular cataracts or secondary cataracts may reflect the intrinsic properties of lens epithelial cells. Interaction between lens epithelial cells and their substratum appears to be an important regulator of myofibroblast formation. Understanding the factors that regulate alpha-SMA expression in lens epithelial cells could lead to the development of methods for preventing secondary cataracts and anterior subcapsular cataracts.

Fibrous membrane formation at the capsular margin in capsule contraction syndrome.

PURPOSE: To determine whether the pathogenesis of capsule contraction syndrome involves the outgrowth of the fibrous membrane from the anterior capsule margin. SETTING: Department of Ophthalmology, Keio University School of Medicine, Tokyo, and the Ando Eye Clinic, Kanagawa, Japan. METHODS: A retrospective review of medical records and slitlamp photographs was conducted in 12 eyes (10 patients) that had required treatment for a narrowed anterior capsule opening after cataract surgery. All patients had had continuous curvilinear capsulorhexis and phacoemulsification with implantation of an intraocular lens in the capsular bag. Specimens of surgically removed fibrous membrane were examined by histopathological methods. RESULTS: Fibrous membrane on the inner surface of the anterior capsule and the linear folds of the anterior capsule were present in each eye. In 10 eyes of 8 patients, the fibrous membrane was on the outer surface of the anterior capsule and covered the capsular folds at its margin. Pathological study showed that this fibrous membrane consisted of the flattened lens epithelial cells that proliferated on the inner and outer surfaces of the shrunken anterior capsule. The outgrowth of this membrane from the margin of the anterior capsule to the center of the opening of the anterior capsule was noted. CONCLUSION: In this study, capsule contraction syndrome involved contraction of the fibrous membrane as well as its outgrowth from the capsule margin.

Myocardial CD36 expression and fatty acid accumulation in patients with type I and II CD36 deficiency.

Long-chain fatty acids (LCFA) are one of the major cardiac energy substrates, so understanding LCFA metabolism may help in elucidating the mechanisms of various heart diseases. CD36 is a multifunctional membrane glycoprotein that acts not only as a receptor for thrombospondin, collagen and oxidized low density lipoprotein but also as a receptor for LCFA. We investigated the relationship between CD36 expression in myocardial capillary endothelial cells and myocardial LCFA uptake in patients with CD36 deficiency. We analyzed CD36 expression in blood cells from 250 patients with heart diseases by means of a flow cytometer. In 218 patients, myocardial LCFA scintigraphy was performed with 123I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP). In 5 patients, myocardial capillary endothelial cells were examined immunohistochemically for CD36 expression. Eleven patients (4%) showed signs of type I CD36 deficiency (neither platelets nor monocytes expressed CD36). Twenty patients (8%) had type II CD36 deficiency (monocytes expressed CD36 but platelets did not). In all 11 patients with type I CD36 deficiency, no BMIPP accumulation was observed in the heart, but in 13 patients with type II CD36 deficiency, BMIPP accumulation in the heart was focally reduced, but there were no patients without BMIPP accumulation in the heart. Although the myocardial capillary endothelial cells from two CD36-positive patients expressed CD36, those from two patients with type I CD36 deficiency did not. In a patient with type II CD36 deficiency, some capillary endothelial cells displayed patchy CD36 expression. CD36 deficiency was documented in 31 (12%) patients with heart diseases. Because CD36 was not expressed in the myocardial capillary endothelial cells in patients with type I CD36 deficiency, type I CD36 deficiency is closely related to lack of myocardial LCFA accumulation and metabolism in the myocardium.

Pupillary block after pupillary capture of an AcrySof intraocular lens.

A 54-year-old man developed pupillary block resulting from pupillary capture 2 months after uneventful phacomulsification and AcrySof intraocular lens (IOL) implantation. The IOL was placed in the bag through a 6.0 mm continuous curvilinear capsulorhexis. The glaucoma was treated with intravenous drip infusion of a hyperosmotic diuretic, followed by peripheral iridectomy, iridocapsular synechiolysis, and IOL repositioning. The IOL loops were located completely in the bag. However, pupillary capture recurred 3 weeks after the surgery, at which time intraocular pressure was normal. The flexibility of the IOL optic and its large overall length and rigid, low-angulated loops were the probable causes for the recurrence of the pupillary capture. The IOL was exchanged for a sulcus-fixated, single-piece poly(methylmethacrylate) lens with 10 degree angulated loops. Pupillary capture did not recur during the follow-up.

Three year prospective, randomized evaluation of intraocular lens implantation through 3.2 and 5.5 mm incisions.

PURPOSE: To compare the long-term clinical results of two small incision cataract surgery procedures. SETTING: Seven centers in Japan. METHODS: Two hundred eyes were randomly assigned to receive a silicone intraocular lens (IOL) through a 3.2 mm incision or a poly(methyl methacrylate) (PMMA) IOL through a 5.5 mm incision. Except for incision size and implantation technique, the surgical methods were identical. Uncorrected and corrected visual acuity, keratometry, flare-cell intensity, specular microscopy, and neodymium:YAG (Nd:YAG) laser posterior capsulotomy rate were analyzed up to 3 years after surgery. RESULTS: Eyes in the 3.2 mm incision group had significantly better uncorrected and corrected visual acuity in the early postoperative period and lower aqueous flare intensity immediately after surgery, but these differences disappeared after the first postoperative month. However, surgically induced astigmatism was significantly less in the 3.2 mm incision group than in the 5.5 incision group throughout the study. The Nd:YAG laser capsulotomy rate was higher in the silicone IOL group (23.5% at 3 years postoperatively) than in the PMMA IOL group (18.4%) but the difference was not statistically significant. CONCLUSION: Smaller incision cataract surgery led to early recovery of visual function in the short term and less induced astigmatism in the long term.

Morphologic compatibility or intraocular lens haptics and the lens capsule.

PURPOSE: To evaluate the mechanical relationship between the intraocular lens (IOL) haptic and the capsular bag by quantitatively analyzing the fit of the haptic with the capsule equator and the capsular bag deformity induced by the implanted lens haptics. SETTING: Division of Morphogenesis, Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan. METHODS: Following implantation of a poly(methyl methacrylate)(PMMA) ring in three excised human capsular bags with continuous curvilinear capsulorhexis (CCC), IOLs with different overall lengths or haptic designs were implanted in the bags and photographed. The straight length of the area of contact between the haptic and the capsule equator on the photographs was measured to provide a quantitative index of in-the-bag fixation and the length from the external margin of the PMMA ring to the external margin of the loop along the maximal diameter of the capsular bag, to indicate the quantitative degree of capsular deformity induced by an IOL. RESULTS: An IOL with modified-C loops produced better fit along the capsule equator and less deformity than an IOL with modified-J loops, and an IOL with an overall length of 12.0 or 12.5 mm produced a sufficiently good fit and less distortion of the capsular bag than an IOL with an overall length over 13.0 mm. CONCLUSION: An IOL with modified-C loops and an overall length of 12.0 or 12.5 mm is adequate for in-the-bag implantation following CCC.

Apoptotic cell death in rabbit lens after lens extraction.

PURPOSE: To determine whether apoptosis or necrosis of lens epithelial cells occurs after lens extraction. METHODS: Lens extraction was performed on 24 rabbit eyes. The authors then performed terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and transmission electron microscopy on the eyes 1 to 10 days after surgery. RESULTS: The postoperative lens was demarcated into three regions by the adhesion between the incised edge of the anterior capsule and the posterior capsule: the adhesive region, the intracapsular region, and the central portion of the posterior capsule. By day 2, TUNEL-positive cells with morphologic characteristics of necrosis were detected in the intracapsular region. Beginning on day 5, TUNEL-positive cells with morphologic characteristics of apoptosis and necrosis were detected in the adhesive region. Apoptotic cell death in this region was detected among the myofibroblast-like cells. Lens epithelial cells that had extended onto the central portion of the posterior capsule began to diminish on day 8 or 9, some of them morphologically demonstrating necrotic changes. CONCLUSIONS: Apoptosis of lens epithelial cells occurs in the process of wound healing and reepithelialization after lens extraction, leading to secondary cataract. If the induction of apoptosis is better understood, protocols might be developed that could prevent reepithelialization through apoptosis, thus delaying or preventing secondary cataracts.

Effect of intraocular lens design on migration of lens epithelial cells onto the posterior capsule.

PURPOSE: To find the conditions that prevent posterior capsule opacification through in vitro analysis of the relationship between intraocular lens (IOL) optic configuration and lens epithelial cell (LEC) migration. SETTING: Division of Morphogenesis, Department of Developmental Biology, National Institute for Basic Biology, Okazaki, Japan. METHODS: In a preliminary experiment, we measured the size of the capsular bag of rabbits at 8, 16, 20, and 26 weeks of age. The size of a 20-week-old capsular bag was the same size as the capsular bag in senescent Japanese eyes. We isolated the capsular bags in 20- and 8-week-old rabbits. The bags along with a biconvex (BC), convex-plano (CP), or no IOL (C) were cultured, and the eyes were divided into one of six groups (8W-C, 8W-BC, 8W-CP, 20W-C, 20W-BC and 20W-CP), each including six specimens. RESULTS: Two specimens in the 8W-CP group completely blocked LEC migration at the optic edge. All specimens in the 20W-CP group and one in the 20W-BC group showed cell aggregation along the optic edge. None of the other specimens in the BC and C groups blocked migration or showed cell aggregation. CONCLUSIONS: In the rabbit-model study, the convex-plano lens was superior to the biconvex lens in inhibiting migration of LECs. A firm contact between the IOL and the posterior capsule blocked the migration.

Elschnig pearl formation along the posterior capsulotomy margin after neodymium:YAG capsulotomy.

PURPOSE: To determine the incidence of Elschnig pearl formation along the capsulotomy margin (string of pearls) after neodymium:YAG (Nd:YAG) laser posterior capsulotomy and to elucidate its clinical features, predisposing factors, effect on visual function, and association with additional capsulotomy. SETTING: Keio University Hospital, Tokyo, Japan. METHODS: The records of 418 eyes that had had Nd:YAG posterior capsulotomy after cataract surgery were retrospectively reviewed. Of those, 315 were excluded for short follow-up (fewer than 12 months) or insufficient clinical examination data. In the remaining 103 eyes, the incidence of string of pearls was calculated, and its clinical features, predisposing factors, effect on visual function, and correlation with additional capsulotomy were evaluated. RESULTS: String of pearls was identified in 49 eyes (47.6%); 37 (75.5%) developed pearls within 1 year after Nd:YAG capsulotomy. The incidence was significantly higher in patients having intraocular lens implantation and continuous curvilinear capsulorhexis (CCC) than in those without (95.9 versus 61.1% and 97.9 versus 55.6%, respectively). No significant differences were found in patient age and sex, total Nd:YAG energy, and the presence of diabetes mellitus or high myopia. String of pearls caused visual disturbances in 17 eyes (34.7%). The rate of repeat capsulotomy was higher in patients with string of pearls than in those without (36.7 and 9.3%, respectively). CONCLUSIONS: String of pearls formation was a common and significant complication after Nd:YAG posterior capsulotomy. Intraocular lens implantation and CCC may promote its formation.

Evaluation of a zonal-progressive multifocal intraocular lens.

PURPOSE: To determine the clinical usefulness of a five-zone refractive multifocal intraocular lens. METHODS: After more than 1 year of follow-up, we evaluated the visual function of 22 patients (36 eyes) who had received the MPC-25NB intraocular lens for distance and near visual acuity, kinetic visual acuity, and near contrast sensitivity, and for patient satisfaction. RESULTS: Of 31 study eyes with less than 1.5 diopters of preoperative keratometric astigmatism, 28 (90.3%) achieved an uncorrected distance visual acuity of 20/40 or better; best-corrected distance visual acuity was 20/20 or better in 31 (86.1%) of 36 eyes. Near visual acuity with distance correction was 20/40 or better in 20 (60.6%) of 33 eyes. Kinetic visual acuity in these patients was comparable to that in patients with monofocal intraocular lenses. Distance visual acuity and near contrast sensitivity were below normal or within the low normal range. There was no significant difference in contrast visual acuity measured by variable contrast visual acuity charts between MPC-25NB and monofocal intraocular lens-implanted eyes (P > .05). Four (22.2%) of 18 patients did not require spectacles when the intraocular lens was implanted for emmetropia. Despite some complaints about near or night vision, all patients expressed satisfaction. CONCLUSIONS: The MPC-25NB lens provides a level of distance vision comparable to that of a monofocal intraocular lens and a useful level of near visual acuity without spectacles. However, we should carefully evaluate the indication for use of MPC-25NB in patients who require good near vision or night vision.

Presence of alpha smooth muscle actin in lens epithelial cells of aphakic rabbit eyes.

AIMS: To determine whether alpha smooth muscle actin (alpha-SMA), a marker for myofibroblastic cells, is present in lens epithelial cells (LECs) in rabbit aphakic eyes. METHODS: Phacoemulsification was performed in rabbit eyes, which were enucleated after surgery. Immunohistochemical methods were used to detect alpha-SMA in LECs. RESULTS: Five days after surgery, the presence of alpha-SMA positive LECs was observed mainly around the adhesive portion of the anterior capsule margin and the posterior capsule. The posterior capsule was wrinkled at the adhesive portion. The alpha-SMA positive LECs were flattened with spindle-shaped cross sections. Seven days after surgery, the alpha-SMA positive LECs covered most of the central posterior capsule. They disappeared 10 days after surgery. On the other hand, the cuboidal LECs in the capsular bag were negative for alpha-SMA. CONCLUSION: The flattened LECs with spindle-shaped cross sections observed 5 days after cataract surgery contained alpha-SMA. Such LECs were distinguished biochemically from the cuboidal LECs, which lacked alpha-SMA.

Pituitary adenylate cyclase-activating polypeptide causes rapid Ca2+ release from intracellular stores and long lasting Ca2+ influx mediated by Na+ influx-dependent membrane depolarization in bovine adrenal chromaffin cells.

Pituitary adenylate cyclase-activating polypeptide (PACAP) has been reported to increase intracellular Ca2+ concentrations ([Ca2+]i) and catecholamine release in adrenal chromaffin cells. We measured [Ca2+]i with fura-2 and recorded ion currents and membrane potentials with the whole cell configuration of the patch-clamp technique to elucidate the mechanism of PACAP-induced [Ca2+]i increase in bovine adrenal chromaffin cells. PACAP caused [Ca2+]i to increase due to Ca2+ release and Ca2+ influx, and this was accompanied by membrane depolarization and inward currents. The Ca2+ release was suppressed by ryanodine, an inhibitor of caffeine-sensitive Ca2+ stores, but was unaffected by cinnarizine, an inhibitor of inositol trisphosphate-induced Ca2+ release. Ca2+ influx and inward currents were both inhibited by replacement of extracellular Na+, and Ca2+ influx was inhibited by nicardipine, an L-type Ca2+ channel blocker, or by staurosporine, a protein kinase C (PKC) inhibitor, but was unaffected by a combination of omega- conotoxin-GVIA, omega-agatoxin-IVA, and omega-conotoxin- MVIIC, blockers of N-, P-, and Q-type Ca2+ channels. Moreover, 1-oleoyl-2-acetyl-sn-glycerol, a PKC activator, induced inward currents and Ca2+ influx. These results indicate that PACAP causes both Ca2+ release, mainly from caffeine-sensitive Ca2+ stores, and Ca2+ influx via L-type Ca2+ channels activated by membrane depolarization that depends on PKC-mediated Na+ influx.

Clinical evaluation of a five-zone refractive multifocal intraocular lens.

PURPOSE: To evaluate the clinical performance of a five-zone refractive multifocal intraocular lens (AMO, model MPC-25NB, Array). METHODS: We performed a retrospective clinical trial of 31 cataract patients (mean age 64.3 years). The parameters studied were intraoperative and postoperative complications, distance and near visual acuity, spectacle use, decreased number of corneal endothelial cells, contrast sensitivity, percentage of glare disability, near binocular vision, and depth of focus. RESULTS: Intraoperatively, iris damage occurred in two eyes (4.2%), vitreous loss in one eye (2.1%), and consecutive rupture of Zinn's zonule and vitreous in one eye (2.1%). Postoperatively, posterior capsule opacification was observed in two eyes (4.2%), temporary intraocular pressure increase in one eye (2.1%), and cystoid macular edema in one eye (2.1%). Uncorrected distance visual acuity of 20/40 or better was achieved by 34 of 37 eyes (91.9%) with less than 1.5 diopters of preoperative keratometric astigmatism; best corrected distance acuity of 20/20 or better was achieved by 41 of 45 eyes (91.1%). Near visual acuity with distance correction of 20/40 or better was achieved by 29 of 43 eyes (67.4%). These data were compared retrospectively with data from control patients who received monofocal lenses, and no significant differences in the decreased number of corneal endothelial cells were found. Mean contrast sensitivities were within normal range for all spatial frequencies. Percentage of glare disability and near binocular vision were within normal limits. CONCLUSIONS: Eyes implanted with the five-zone refractive multifocal lens showed better near visual acuity than control eyes and compared favorably in other aspects of visual function, indicating that these lenses are effective and safe.

Lens epithelial cell migration onto the posterior capsule in vitro.

PURPOSE: To investigate lens epithelial cell (LEC) proliferation on the posterior capsule in an in vitro model. SETTING: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. METHODS: We cultured the cells remaining on the postoperative capsular bag and expanded the capsule with an open poly(methyl methacrylate) ring to simulate actual postoperative conditions. Using human and rabbit cadaver eyes, we monitored the migration and proliferation of LECs onto the postoperative capsular bag by time-lapse videomicroscopy. RESULTS: The remaining viable cells migrated onto the posterior capsule through the equator and directly from the anterior capsule. The cells typically proliferated in a monolayer because of contact inhibition of cell movement and division, but they proliferated in a multilayer at some regions where nonviable cells had accumulated and there were capsular folds. CONCLUSION: A means to block both routes of cell expansion must be developed to prevent LEC migration onto the posterior capsule.

Lens epithelial cell proliferation onto the intraocular lens optic in vitro.

PURPOSE: To determine how lens epithelial cells (LECs) proliferate onto an intraocular lens (IOL) after extracapsular cataract surgery. SETTING: Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan. METHODS: We cultured the capsular bags retaining LECs of eight human eye-bank eyes and six rabbit eyes that had had extracapsular lens extraction with in-the-bag implantation of a poly(methyl methacrylate) (PMMA) IOL and a PMMA ring. Cell proliferation onto the IOL optic was monitored by a time-lapse video system. RESULTS: Cells proliferated onto the IOL optic via the anterior capsulotomy margin, the inner surface of the anterior capsule, and the posterior capsule. They formed cell sheets similar to the membranes observed in clinical cases. CONCLUSIONS: Since the cells proliferated from the anterior capsule as well as from the posterior capsule onto the IOL optic, the membranes observed clinically on the IOL optic may be LEC sheets.

Effect of intraocular lens design on posterior capsule opacification after continuous curvilinear capsulorhexis.

We compared the effect of biconvex and convex-plano (posterior plano) intraocular lenses on posterior capsule opacification (PCO) following continuous curvilinear capsulorhexis (CCC) in 212 eyes. During the three years following surgery, the cumulative frequency of neodymium:YAG laser posterior capsulotomy, calculated with the Kaplan-Meier method, was significantly higher in patients in the biconvex group (32.5% by the third year) than in those in the convex-plano group (5.9% by the third year) (P < .05, Wilcoxon's test; P < .01, Cox-Mantel's test). Measured with the tracing method, the area within a 5 mm diameter central circle that developed Elschnig pearls was 2.93 +/- 4.91 mm2 in the biconvex group and 1.66 +/- 2.37 mm2 in the convex-plano group. In the study, PCO was less severe in the convex-plano group than in the biconvex group following CCC. These results are contrary to those reported previously in patients with can-opener capsulotomy.

Growth factors influence contractility and alpha-smooth muscle actin expression in bovine lens epithelial cells.

PURPOSE: To determine whether basic fibroblast growth factor (bFGF) and transforming growth factor-beta 2 (TGF-beta 2) influence the contractile activity and the expression of alpha-smooth muscle actin (alpha-SMA) in bovine lens epithelial cells (LECs). To examine whether modulation of contractile activity by these growth factors depends on changes of alpha-SMA expression. METHODS: Bovine LECs were cultured in collagen gel in MED 5 medium (F-12 nutrient mixture supplemented with 5% fetal bovine serum) with or without bFGF (1 to 100 ng/ml) or TGF-beta 2 (0.01 to 10 ng/ml). To evaluate collagen gel contraction, the longest and shortest diameters of the gels were measured daily for 7 days, and the area was determined. Detection of alpha-SMA in the gels was performed immunohistochemically using a mouse monoclonal antibody against alpha-SMA. The percentage of alpha-SMA-positive cells to the total number of cells was determined. RESULTS: Control gels cultured with MED 5 medium alone contracted to 15.8% +/- 3.4% of their original area after 7 days. TGF-beta 2 significantly increased this contraction in a dose-dependent manner, whereas bFGF significantly decreased it. Approximately 30% of cells in the control gels were alpha-SMA positive. TGF-beta 2 significantly increased the alpha-SMA positivity dose dependently, whereas bFGF significantly decreased it. The percent positivity for alpha-SMA and the gel area showed a significant negative correlation. CONCLUSIONS: TGF-beta 2 increased collagen gel contraction and alpha-SMA expression in bovine LECs, whereas bFGF decreased these parameters. Because collagen gel contraction was correlated with alpha-SMA expression, the modulation of LEC contractile activity by growth factors may be related to an effect on alpha-SMA.