ISSN:0271-3683    

DOI:10.3109/02713688608996368

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Change of urate and ascorbate levels in retinae of rat left eyes after ophthalmic artery and optic nerve ligation was studied by reversed-phase high-performance liquid chromatography with electrochemical detection. The right eyes were used for sham operation. We found that uric acid levels in the retinae of the left eyes increased as a function of time after the operation, whereas those of the right eyes remained unchanged. In addition, we found that ascorbic acid levels in the retinae of the rat eyes decreased after the operation.

ISSN:0271-3683    

DOI:10.3109/02713688608996369

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

We investigated the combined fluorescent dyes acridine orange (AO) and ethidium bromide (EB) for corneal endothelial evaluation. Both dyes intercalate with DNA and RNA and are mutagenic at high concentrations. Optimum differential staining was obtained after 5 minutes exposure to 1 ug/ml of each dye. Electron microscopy confirmed that the dye combination simultaneously identified both viable and nonviable cells. Swelling of perfused dog corneas for 3 hours after exposure to both dyes for 5 minutes was not increased. Exposure to visible light from a fluorescence microscope for 2–5 minutes caused increased corneal swelling and abnormal intercellular junctions by electron microscopy in paired dog corneas stained for 5 minutes with either AO or EB. The addition of 10% calf serum to the staining and observation media decreased the toxic effect of AO/EB and light seen by specular microscopy and by electron microscopy. Human corneas exposed to AO and EB were not mutagenic in the Salmonella/microsome assay. These results indicate that AO and EB, 1 lag/ml, provide a rapid identification of both viable and nonviable corneal endothelial cells. When the corneas are exposed to light, however, the dyes are toxic; this toxicity is decreased by the presence of 10X calf serum in the staining and observation media.

ISSN:0271-3683    

DOI:10.3109/02713688608996370

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Forskolin has been reported to stimulate cAMP formation and reduce intraocular pressure in rabbit and primate eyes. In view of recent evidence for the involvement of cAMP in modulation of transmitter release at adrenergic synapses, we have investigated the presynaptic effects of forskolin and other cAMP activators on field-stimulated secretion of H-norepinephrine (3H-NE) in the isolated, perfused rabbit iris-ciliary body. Forskolin (10−7-10 M−5) was Jiound to markedly enhance stimulation-evoked3H-NE release without affecting basal (spontaneous) release. The response to forskolin was potentiated by the phosphodiesterase inhibitor isobutylmethylxanthine (IBMX; 0.5 mM) and was mimicked by the cell-permeant cyclic nucleotide analog 8-bromo-cAMP. 8-bromo-cGMP also, produce a small enhancement of stimulus-evoked H-NE secretion, whereas IBMX alone had little effect on either stimulated or basal secretion. These results suggest that cAMP may play an important neuromodulatory role in regulation of norepinephrine release at intraocular synapses, and raise the possibility that the ocular hypotensive response to forskolin in rabbit eyes may be mediated, in part, by enhanced adrenergic neurosecretion.

ISSN:0271-3683    

DOI:10.3109/02713688608996371

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Proteases are involved in the pathogenesis of Pseudomonas aeruginosa infections of the cornea. Although there are many potential roles for these enzymes, involvement in corneal stroma destruction with subsequent descemetocele formation and/or corneal perforation is an important example. This study examined the relationship of elastase and alkaline protease to corneal destruction as indicated by descemetocele formation. The protease content of the overnight Mueller-Hinton broth cultures of various strains ofP. aeruginosa correlated with the production of descemetoceles both in the rabbit trauma model of Pseudomonas keratitis and upon intrastromal injection of filtrates of the overnight culture media. The levels of alkaline protease correlated better with descemetocele formation than those of elastase. The influx of inflammatory cells was not correlated with descemetocele formation within 24 to 48 hrs.

ISSN:0271-3683    

DOI:10.3109/02713688608996372

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

To gain information on the role of cyclic AMP (cAMP), ion transport and cell membrane permeability on aqueous humor formation, agents with well-known effects on transport properties in other epithelia were tested on the isolated rabbit iris-ciliary body. Forskolin stimulated the short-circuit current (SCO by 37.5? when added to the aqueous-side solution. Forskolin was ineffective when added to the blood-side solution or when HCCC was absent from the bathing solutions. The effect of forskolin confirms the presence of adenylate cyclase in the ciliary epithelium and the involvement of cAMP in ion transport. In HCOl-rich media, 5×10″M prostaglandin F2α. (PGF-α), produced a prompt25%increase in the SCC when added to the aqueous-side, and a small stimulatory SCC response when added to the blood-side. No change in SCC occurred when PGFαwas added to either side of a HCO3-free bathing solution. It is implied that cAMP acts on a HCO3dependent transport system. These results are consistent with the previously observed stimulation of the SCC by 8Br-cAMP. Ba, 2.5 mM, on the aqueous-side increased the SCC by 240.5%, but reduced the SCC by 26%when 2+ added to the blood-side solution. The Ba effects indicate the presence of high conductance K+channels in the basolateral membranes of both the pigmented and non-pigmented cell layers.

ISSN:0271-3683    

DOI:10.3109/02713688608996373

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

We evaluated the efficacy of N-Acetyl-Aspartyl-Glutamic acid (magnesium salt) (NAAGA) eye-drops in preventing the conjunctival and uveal allergic inflammation induced by reverse passive Arthus reaction in the rabbit. The permeability of the blood-conjunctival and blood-aqueous barriers was investigated by the leakage of125I-labelled rabbit serum albumin injected intravenously prior to the challenge with the antigen. Permeability of both barriers was markedly increased 2 hours after the triggering of the allergic reaction; marked edema of the conjunctiva was also observed. Pretreatment with 1, 3,6% (w/w) NAAGA eye-drops prevented the conjunctival inflammatory changes in a dose related manner and to a lesser degree, the breakdown of the blood-aqueous barrier. The distribution of topically applied14C-NAAGA in the rabbit eyes was also investigated.

ISSN:0271-3683    

DOI:10.3109/02713688608996374

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

The influence of an X-ray dose of 10 Gy (1000 rads) on mitosis in the rat conjunctival epithelium was assessed. A mitotic inhibition began 1 hour postirradiation and continued for 4 days. The mitotic index was depressed to 10% of control values. After 5 days postirradiation, the mitotic index surpassed the control values peaking at 7 days postirradiation.The spindle axes of cells in telophase of the perilimbal rat conjunctival epithelium assume a characteristic, three dimensional orientation relative to the limbus. Ionizing radiation did not disrupt this organization at any time postirradiation. In fact, the frequency of mitotic figures preferentially aligned in irradiated tissue was enhanced during the mitotic rebound.

ISSN:0271-3683    

DOI:10.3109/02713688608996375

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Microsomes were prepared from bovine ciliary bodies. The contents of cytochrome P-450 and related components of the microsomal electron transport system were determined. The cytochrome P-450 content was 32 pmoles/mg protein, which was about 4% that in rat liver. The cytochrome b5content was 59 pmoles/mg protein. The NADH-cyto−chrome c reductase and NADPH-cytochrome c reductase activities were 268 and 18 nmoles/min/mg protein, respectively. The ethoxyresorufin deethyl-ase activity was 2.1 pmoles product formed/min/mg protein.

ISSN:0271-3683    

DOI:10.3109/02713688608996376

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor

摘要:

Tumor-promoting phorbol esters have been shown to modulate a number of physiological events in various cell types, and these events are associated with the activation of protein kinase C. The purpose of this study was to examine the effects of phorbol ester stimulation on protein kinase C activity and epithelial ion transport in the Cl−secreting rabbit corneal epithelium. We report here that nanomolar concentrations of tumor-promoting phorbol ester, 12-0-tetradecanoyl-phorbol-13 acetate (TPA), stimulate active ion transport via a putative receptor located in the corneal epithelium. This stimulation is a Cl−dependent process, but is independent of 6-adrenergic receptor activation and prostaglandin formation. Biochemical data support the idea that TPA activates Ca++/phospholipid-dependent protein kinase C in the corneal epithelium. Therefore, we suggest that protein kinase C may have a role in the regulation of membrane C1−transport in the mammalian corneal epithelium.

ISSN:0271-3683    

DOI:10.3109/02713688608996377

出版商:Taylor&Francis    

年代:1986

数据来源: Taylor