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PubMed1994

Comparison of interactions of R(+)- and S(-)-isomers of beta-adrenergic partial agonists, befunolol and carteolol, with high affinity site of beta-adrenoceptors in the microsomal fractions from guinea-pig ciliary body, right atria and trachea.

1. The stereoselectivities of beta-adrenergic partial agonists for the high affinity binding site of beta-adrenoceptors in the guinea-pig ciliary body, right atria and trachea were studied. 2. The inhibition curves by the S(-)-isomers of befunolol and carteolol were not significantly different from that by the R(+)-isomers in the guinea-pig ciliary body. 3. The inhibition curves by the S(-)-isomers of befunolol and carteolol were about 10 times as potent as the R(+)-isomers in the guinea-pig atria and trachea. 4. The pKi values of the S(-)-isomers of befunolol and carteolol were significantly larger than those of R(+)-isomers in the guinea-pig atria and trachea but not larger than those of the R(+)-isomers in the guinea-pig ciliary body. 5. These results suggest that the high affinity binding site of beta-adrenoceptors in ciliary body cannot discriminate stereoselectively between the R(+)- and S(-)-isomers, while in other tissues there is stereoselectivity between the two enantiomers.

Adrenergic beta-Agonists↗

PubMed1994

Different iris coloration and uptake of a fluoroquinolone agent into the iris ciliary body of rabbit eyes.

In order to know the correlation of a drug with high affinity to melanin in the iris ciliary body with the amount of melanin contained in the iris ciliary tissues, an in vivo study was performed on pigmented rabbits with brown or blue irises and albino rabbits. The melanin concentrations in the iris ciliary bodies of pigmented rabbits with brown and blue irises and nonpigmented rabbit eyes with whitish irises were determined. The mean concentrations of melanin in the eyes with brown-, blue- and whitish-colored irises were 47.43, 34.73 and below 0.2 microgram/mg tissue, respectively. The amount of sparfloxacin uptake in the iris ciliary bodies of eyes with brown, blue and whitish irises administered as 40 microliters of 0.3% solution 5 times every 5 min was 15.46 +/- 2.07, 8.53 +/- 1.87 and 1.9 micrograms/g, respectively. The results may be useful for intraocular drug dynamics studies.

Administration, Topical↗

PubMed2004

Prognostic factors for survival after enucleation for choroidal and ciliary body melanomas.

PURPOSE: To evaluate prognostic factors for the survival of patients treated by enucleation for choroidal and ciliary body melanomas. METHODS: The study included 293 consecutive patients (147 men and 146 women) treated by enucleation for a choroidal or ciliary body melanoma during the period 1955-2000. The median age at treatment was 61 years (range 26-88 years). Clinical and histopathological findings, vital status at October 1st, 2002, and cause of death were registered. Prognostic factors for survival were evaluated by univariate and multivariate Cox proportional hazards analysis and by Kaplan-Meier survival analysis. RESULTS: Follow-up was complete. The median follow-up time was 6.2 years (range 21 days to 43.4 years) and the median potential follow-up time was 25.7 years (range 1.9-47.7 years). In multivariate Cox proportional hazards analysis an increased risk of melanoma-related death was found for largest basal diameter (n = 264, p < 0.001, mortality rate ratio (RR) = 1.09 for continuous parameter in mm), anterior tumour margin at the iris/ciliary body versus choroid (p < 0.001, RR = 2.22), and non-spindle cell type versus spindle cell (p = 0.047, RR = 1.45). An increased risk of death from all causes was found for men versus women (n = 266, p = 0.02, RR = 1.41), high age (p < 0.001, RR = 1.41 for continuous parameter in 10-year age groups), largest basal diameter (p < 0.001, RR = 1.07), anterior tumour margin at the iris/ciliary body (p = 0.02, RR = 1.52), and non-spindle cell type (p = 0.04, RR = 1.34). CONCLUSION: The risk of melanoma-related death after enucleation for a choroidal or ciliary body melanoma was high for tumours with large basal diameter, of non-spindle cell type and anterior location. Additional risk factors for death from all causes were male sex and high age.

Adult↗

PubMed1996

[The effect of mitomycin C on activities of carbonic anhydrase and ATPase of the ciliary body epithelium in rabbit].

PURPOSE: Enzymohistochemical methods were performed to observe the effect of mitomycin C(MMC) on the activities of carbonic anhydrase (CA) and ATPase of the ciliary body epithelium in rabbits after using 0.2mg/ml mitomycin C during sclerectomy for the further study on the mechanism of the decrease of intraocular pressure postoperatively. METHODS: 0.2mg/ml mitomycin C was topically applicated during the sclerectomy in rabbit eyes. 7 days postoperatively, Hasson's method and plumbum nitrate's method were used to stain the CA and ATPase of the ciliary body epithelium. The grey value of the enzymes was quantitated by Image Analysor. RESULTS: MMC inhibited the activities of CA and ATPase of the ciliary body epithelium underlying the site of MMC application, but the difference of enzymatic activities of the region 90 degree apart from the surgical site and that of surgical site in normal saline control group was not statistically obvious (P < 0.05). CONCLUSIONS: MMC could inhibit the activities of CA and ATPase of ciliary body epithelium, thus leading to the decreased secretion of humor aqueous and the lowerdown of intraocular pressure even persistent hypotony.

Adenosine Triphosphatases↗

PubMed1994

Production of interleukin-6 and granulocyte-macrophage colony-stimulating factor by murine iris and ciliary body explants.

PURPOSE: To examine the ability of murine iris-ciliary body explants to produce cytokines with proinflammatory activities. METHODS: Supernatants derived from murine iris-ciliary body (I-CB) tissue explants cultured (four per well in 1 ml medium) in the presence of indomethacin were analyzed for the production of IL-1, IL-2, IL-3, IL-6, tumor necrosis factor-alpha/beta (TNF alpha/beta) and granulocyte-macrophage colony-stimulating factor (GM-CSF). Analysis was performed by thymocyte costimulation, growth factor-dependent cell proliferation, TGF-beta-sensitive mink lung epithelial cell proliferation, and enzyme-linked immunosorbent assays (ELISA). RESULTS: Supernatants from I-CB explants cultured in vitro for 24 hours contained significant thymocyte costimulatory activity. This activity was fully neutralized by a combination of antisera to IL-1 and IL-6, and ELISA analysis confirmed that IL-6 was a significant component of the supernatant (402.7 pg/ml). TNF alpha/beta were also found in low concentrations (approximately 2.0 U/ml) by ELISA analysis, whereas IL-2 and IL-4 were not detectable. Significant amounts of GM-CSF (15.8 U/ml), but no IL-3, were detected. CONCLUSIONS: These results demonstrate that normal I-CB tissue contains cells capable of producing IL-6, GM-CSF, and IL-1. Because of the proinflammatory nature of IL-6 and IL-1, and the ability of GM-CSF, IL-1, and IL-6 to enhance functional capabilities of antigen presenting cells, regulation of the production of these cytokines may contribute significantly to the maintenance of the immunologic status of this regional site.

Animals↗

PubMed1986

Effects of chlorpromazine-pretreated melanin on lysosomal acid phosphatase and N-acetyl-beta-D-glucosaminidase in bovine ciliary body and iris in vitro.

We studied biochemically the effect of chlorpromazine-pretreated melanin on lysosomal enzyme activities in the bovine ciliary body and iris in vitro. Melanin was prepared from the bovine ciliary body and iris by acid treatment. Acid phosphatase and N-acetyl-beta-D-glucosaminidase of the ciliary body and iris were used as lysosomal marker enzymes. After the enzyme solution was incubated with melanin, enzyme activity was reduced and protein content in the supernatant was decreased. When melanin was pretreated with chlorpromazine, both enzyme activity and protein content in the supernatant remained higher than after the incubation with melanin alone, depending on the concentration of chlorpromazine. Chlorpromazine itself seemed to have little effect on the acid phosphatase and N-acetyl-beta-D-glucosaminidase at the concentration used in the incubation mixture. The increased enzyme activity, therefore, may result from a loss of the enzyme affinity for melanin after chlorpromazine pretreatment. These findings were discussed with respect to the binding mechanism of lysosomal enzymes to melanin and possible effect of chlorpromazine on biochemical interaction between lysosomal enzymes and melanin in vivo.

Acetylglucosaminidase↗

PubMed1992

Immunosuppressive factors in porcine ciliary body.

Immunosuppressive factors locally present in the anterior tissues such as the ciliary body may contribute to the immunological privilege of the anterior chamber of the eye. Porcine ciliary body extracts contain at least three immunosuppressive factors (greater than 200 kDa, 25 kDa and 2.5 kDa) which can be separated by Sephacryl S300 gel filtration. On the basis of its molecular weight and reversal of inhibitory activity by anti-transforming growth factor beta (TGF beta) antibody, 25 kDa factor is identified with TGF beta. The high molecular factor is low in protein content and its activity is not affected by anti-TGF beta antibody. The 2.5 kDa factor is most likely to be identical with a low molecular factor present in the vitreous body and aqueous humor. This low molecular factor is extracted from nonpigmented ciliary epithelial cells but seems to be absent in the extracts of pigmented epithelial cells. The regional distribution suggests that the factor may be synthesized and secreted with the aqueous humor by the nonpigmented cells. All three factors suppress lymphoblastogenesis without affecting the expression of CD4 and CD8. Identical or similar factors may be present in other immunologically privileged tissues and be responsible for maintaining the immunologically suppressed environment.

Animals↗

PubMed1988

Monoclonal antibodies to the H+-K+ ATPase of gastric mucosa selectively stain the non-pigmented cells of the rabbit ciliary body epithelium.

Monoclonal antibodies developed against the transport enzyme H+-K+ ATPase of gastric mucosa selectively bind to the nonpigmented cell layer in both the pars plana and pars plicata of the rabbit ciliary body epithelium. The most specific of these antibodies (HK 12.18) reacts with the nonpigmented cells but with no other cell type in ciliary body, retina or iris. Antibody reactivity is evinced by a distinct particulate staining which is greater on the surfaces of the nonpigmented cells than within the cytoplasm and seems most intense on the apical membrane between the pigmented and nonpigmented cell layers. This pattern of staining was present in 2-3-day-old pups and in young adults, in both pigmented and albino animals. Similar staining was not observed in control sections treated with preimmune serum, nonspecific mouse monoclonal antibody, or HK 12.18 preabsorbed to gastric microsomes. In addition to staining intact ciliary body, the antibody HK 12.18 can be shown to react with a population of cells lacking pigment granules in suspensions of dissociated ciliary body epithelium. This antibody may therefore be useful as a marker for the identification of nonpigmented cells in tissue culture.

Animals↗

PubMed1995

[Distribution of alpha 2,3-sialyltransferase mRNA in rat iris and ciliary body].

The distribution of alpha 2,3-sialyltransferase (alpha 2,3-ST) mRNA in the rat iris and ciliary body was investigated with in situ hybridization histochemistry. Strong expression of alpha 2,3-ST mRNA was detected in the inner epithelial layer of the ciliary body and weak expression in the iris epithelium. Since the synthesis of sialoglycoconjugates is completed by terminal sialylation by the action of sialyltransferase (ST), the ST-expressed portions are considered to produce sialoglycoconjugates. Hence, the source of the sialoglycoconjugates found in the inner epithelial layer of the ciliary body in previous histochemical studies is the same epithelial cell.

Animals↗

PubMed1987

Movement of fluorescein and fluorescein glucuronide across the isolated rabbit iris-ciliary body.

Movement of fluorescein and fluorescein glucuronide, a fluorescent metabolite of fluorescein, across the isolated iris-ciliary body of the albino rabbit was determined under short-circuit conditions using a modified Ussing's chamber. The permeabilities of this tissue to these dyes were calculated. The outward permeability (from the aqueous to the stromal side) of the iris-ciliary body preparation averaged 6.63 +/- 0.86 for fluorescein and 1.51 +/- 0.47 X 10(-6) cm/sec for fluorescein glucuronide, and the inward permeability (from the stromal to the aqueous side) was 1.68 +/- 0.41 for fluorescein and 1.37 +/- 0.77 X 10(-6) cm/sec for fluorescein glucuronide, respectively. Application of probenecid or ouabain decreased the outward permeability of fluorescein, but it had no significant effect on the fluorescein glucuronide movement. Application of 10(-5) M 2,4-dinitrophenol showed no significant effect on the fluorescein or fluorescein glucuronide movement, but application of 5 X 10(-4) M 2,4-dinitrophenol decreased the outward fluorescein transfer, which was also markedly suppressed by incubation at 0 degrees C. It is possible that an active transport mechanism is involved in the outward fluorescein movement across the iris-ciliary body, while the inward movement of fluorescein and also the fluorescein glucuronide movement across this tissue is mainly by passive diffusion.

2,4-Dinitrophenol↗

PubMed1994

Characterization of alpha 2-adrenoceptor binding sites in rabbit ciliary body membranes.

PURPOSE: This study sought to identify and characterize subtypes of alpha 2-adrenoceptors in rabbit ciliary body. METHODS: Radioligand binding assays were performed with the alpha 2-agonist ligand [125I]-p-iodoclonidine ([125I]PIC) and the antagonist ligand [3H]rauwolscine. RESULTS: Both [125I]PIC and [3H]rauwolscine bound to a single population of receptors in membrane preparations of rabbit ciliary body. The densities for the two ligands were the same (about 640 fmol/mg). However, the affinity of [125I]PIC (dissociation constant, Kd = 1.91 +/- 0.24 nM) was about threefold higher than that of [3H]rauwolscine (dissociation constant = 6.79 +/- 1.5 nM), and binding of [125I]PIC exhibited guanine nucleotide sensitivity. Inhibition of [125I]PIC binding by epinephrine, idazoxan, and amiloride was examined to differentiate between alpha 2-adrenoceptors and the imidazoline-preferring receptor. Epinephrine and idazoxan competed for all of the [125I]PIC binding; relative potency was epinephrine > idazoxan >> amiloride. Subtypes of alpha 2-adrenoceptors were further studied by competition for [125I]PIC binding by subtype-selective compounds. [125I]PIC binding sites showed the pharmacologic characteristics of an alpha 2A-adrenoceptor (oxymetazoline > chlorpromazine >> prazosin), and competition by oxymetazoline and chlorpromazine was best fit by a one-site model. Likewise, the relative potency of inhibition of [3H]rauwolscine binding was oxymetazoline > chlorpromazine. However, inhibition of [3H]rauwolscine-binding by oxymetazoline was better fit by a two-site model, which was converted to a one-site model in the presence of 100 microM 5'-guanylimidodiphosphate. CONCLUSIONS: A large number of alpha 2-adrenoceptors are present in rabbit ciliary body. They are not the imidazoline-preferring receptor but are alpha 2-adrenergic-specific receptors of the alpha 2A subtype.

Affinity Labels↗

PubMed1977

Intravitreal ciliary body neovascularization.

Two patients demonstrated an unusual conformation of intravitreal neovascularization, in which the abnormal blood vessels originated from the ciliary body. One of the patients had recurrent anterior chamber and vitreous hemorrhages. Both patients had undergone thermal ablative therapy of the ciliary body for the control of intraocular pressure. In one patient, fibrovascular tissue emanated directly from old cyclocryotherapy scars on the pars plana. Such neovascularization may represent a previously unrecognized complication of attempts at therapeutic destruction of the ciliary body.

Blood Vessels↗

PubMed2002

P2 purinergic receptor-coupled signaling in the rabbit ciliary body epithelium.

PURPOSE: To identify and characterize P2 purinergic receptors and their signaling pathways in the epithelial cells of the rabbit ciliary body. METHODS: Real-time fluorescence ratio imaging of the intact fura-2-loaded nonpigmented ciliary body epithelial (NPE) cells of rabbit were used to record changes in the intracellular free calcium concentration ([Ca(2+)](i)), in response to a number of purinergic agonists and antagonists. The effects of some of these drugs on the inositol phosphate (IP) levels in ciliary processes were also examined. RESULTS: Adenosine diphosphate (ADP), adenosine triphosphate (ATP), and uridine triphosphate (UTP) dose dependently increased the [Ca(2+)](i) and IP levels. The [Ca(2+)](i) increases induced by ADP and UTP were distinguishable, both kinetically and pharmacologically. The effect of ADP on [Ca(2+)](i) was mimicked by a number of P2Y(1)-selective agonists, and was blocked by three P2Y(1)-receptor-specific antagonists. The [Ca(2+)](i) increases elicited by ADP (or its analogs) and UTP were additive. CONCLUSIONS: Rabbit ciliary body epithelium possesses both P2Y(1) and P2Y(2) metabotropic purinergic receptor subtypes, which differentially use the IP(3)/Ca(2+) second-messenger pathway.

Adenine Nucleotides↗

PubMed1993

Prejunctional receptors and second messengers for angiotensin II in the rabbit iris-ciliary body.

Angiotensin II has been shown to act prejunctionally to facilitate sympathetic neutrotransmission in various tissues including the iris-ciliary body. In the present study, we characterized the prejunctional angiotensin II receptor subtype and its signal transduction pathway in the rabbit iris-ciliary body. Angiotensin II caused concentration-dependent facilitation of electrically evoked [3H]-norepinephrine overflow from the isolated, superfused rabbit iris-ciliary body without affecting basal tritium efflux. Responses to angiotensin II were antagonized by saralasin and DuP753 but not by PD123177 indicating that prejunctional angiotensin II receptors of the AT1-subtype mediate the facilitation of evoked [3H]-norepinephrine release. The non-selective cyclic nucleotide phosphodiesterase inhibitor, isobutylmethyl xanthine enhanced the angiotensin II response whereas the cAMP-specific phosphodiesterase inhibitor, RO-20-1724 had no effect. In the presence of 8-bromo-cGMP, responses elicited by angiotensin II were significantly (P < 0.01) greater than that caused in the absence of 8-bromo-cGMP. In contrast, 8-bromo-cAMP had no effect on the angiotensin II-induced response. Guanylate cyclase inhibitors, methylene blue and LY83583 abolished angiotensin II-induced enhancement of [3H]-norepinephrine overflow without affecting basal tritium efflux. Taken together, these results suggest that cGMP could be involved in the angiotensin II response. Neither phospholipase C inhibitors (neomycin, 2-nitro-4-carboxyphenyl-N,N-diphenyl carbamate and phenylmethylsulfonyl fluoride) nor an inhibitor of protein kinase C (staurosporine) had any significant effect on the angiotensin II response, indicating that metabolites of inositol phospholipid metabolism or activation of protein kinase C are not involved in the response to this peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin II↗

PubMedDate not supplied

Ultrasound biomicroscopy features of iris and ciliary body melanomas before and after brachytherapy.

BACKGROUND AND OBJECTIVE: To determine ultrasound biomicroscopy (UBM) features of iris and ciliary body melanomas before and after brachytherapy. PATIENTS AND METHODS: Four uveal anterior melanoma cases undergoing brachytherapy were retrospectively studied. All cases were examined by UBM prior to treatment and repeatedly after treatment. RESULTS: Before brachytherapy, UBM examination showed a solid mass in the iris, ciliary body, or both in all four cases and allowed its characterization, sizing, and positioning. Two cases had a pigmented scleral lesion corresponding to the tumor location, but UBM did not detect any scleral infiltration at those sites. After brachytherapy, all lesions showed progressive decrease in size and progressive attenuation of their limits. Internal reflectivity was variable. Complications related to brachytherapy were demonstrated, including cataract, peripheral anterior synechiae at tumor location, and secondary scleral thinning. CONCLUSION: UBM played an important role as a complementary diagnostic method for anterior uveal melanomas, particularly ciliary body melanomas, but also allowed therapeutic planning (brachytherapy or surgery) and follow-up after treatment.

Aged↗

PubMed1978

The ciliary body and the iris in experimental uveitis in rabbits. A scanning electron microscopic study.

Acute anterior immunogenic uveitis of varying degree was induced in rabbits by the injection of human serum albumin into the vitreous body. After fixation and drying by the critical point method, the lens, the zonules, the vitreous and, in some specimens, coagulated exudate were removed by careful dissection. The surface of the ciliary body and the posterior surface of the iris were examined by scanning electron microscopy. In moderate uveitis, the ciliary body was covered by a thin layer of leucocytes enmeshed in fibrin strands. Scattered deposits of fibrin and a few leucocytes were also found in the iris. In severe uveitis, the processes of the ciliary body had nearly disappeared because of oedema and exudate, which also contained erythrocytes. The numerous leucocytes had marked excrescences formed by folds of the cell membrane. Fibrin seemed to play a role in the attachment of the leucocytes on the surface of the ciliary body.

Acute Disease↗

PubMed1987

A comparative study on the uptake of ascorbic acid by the iris-ciliary body of the rabbit, guinea pig and rat.

1. The uptake of 14C-ascorbic acid by the iris-ciliary body in vitro was examined in the rabbit, guinea pig and rat. 2. It was observed that iris-ciliary body from the rabbit and guinea pig, but not the rat, accumulated 14C-ascorbate to levels exceeding that in the bathing medium. 3. In all three species, the uptake of 14C-ascorbate was diminished by cold temperature; the degree of uptake at 0 degrees C was similar in the rabbit, guinea pig and rat iris-ciliary body. 4. Chromatographic examination of the 14C accumulated by the rabbit and guinea pig tissue demonstrated that the label remains almost exclusively as 14C-ascorbate.

Animals↗

PubMed2004

Expression of serotonin receptor mRNAs in human ciliary body: a polymerase chain reaction study.

BACKGROUND: Previous research has indicated a role for serotonin (5-HT) in the anterior uvea of the eye. The purpose of this study was to examine whether mRNAs encoding particular 5-HT receptors are expressed in the ciliary body and iris of a number of human subjects. METHODS: The presence of mRNA encoding 5-HT receptors in four human ciliary body samples was determined by reverse transcription-polymerase chain reaction experiments using a standard methodology. RESULTS: Positive signals for 5-HT(1A), 5-HT(2A), 5-HT(2B), 5-HT(2C) and 5-HT(7) receptor mRNAs were detected in the samples prepared from various human ciliary body samples. CONCLUSION: The detection of certain 5-HT receptor mRNAs in the human ciliary body supports the hypothesis that serotonin is involved in the control of aqueous dynamics and indicates that ligands acting on these 5-HT receptors may have potential use as intraocular pressure-lowering agents.

Ciliary Body↗