OBJECTIVETo investigate the effect of the non adrenergic non cholinergic nerve (NANC) and substance P (SP) in allergic rhinoconjunctivitis by observing histamine nasal provocation induced conjunctivitis in guinea pigs.

METHODSForty male guinea pigs were randomly divided into five groups with each group consisting of eight guinea pigs. All anesthetized guinea pigs were exposed either to histamine (0.2%, 5 µl) (group B~E) or saline (5 µl, group A) via unilateral nostril. No pretreatment was done in group A and B while pretreatment was done in groups C~E through injection into the unilateral common carotid artery with cholinergic nerve inhibitor (atropine, 1 mg/kg, group C), cholinergic nerve inhibitor plus adrenergic nerve inhibitors (atropine, 1 mg/kg, phentolamine, 1 mg/kg plus Esmolol, 1 mg/kg, group D) and cholinergic nerve inhibitor, adrenergic nerve inhibitors plus SP receptor antagonist (the same treatment with group D plus D-SP 10(-6) mol/L, 1 µl/g, group E), respectively. To assess the ipsilateral conjunctival inflammatory reaction, conjunctiva leakage with Evans blue dye assessments and HE staining of conjunctival tissues were performed. The SP expression in ipsilateral conjunctival tissue in different groups of guinea pigs were assessed by immunofluorescence and RT-PCR. The activity of eosinophils was assessed by eosinophil major basic protein 1 (MBP1) with RT-PCR, meanwhile, the activity of mast cells was assessed by tryptase with RT-PCR. SPSS 17.0 software was used to analyze the data.

RESULTSAt 30 min after nasal application of histamine, ipsilateral conjunctivitis was successfully induced as shown by the change of conjunctiva leakage and histology. The content of Evans blue in ipsilateral conjunctival tissue of group A~E was (13.78 ± 2.48), (29.62 ± 3.31), (19.03 ± 1.47), (18.42 ± 2.52), (14.83 ± 2.14) µg/ml, respectively. There was statistically significant difference between group A and B (t = -10.66, P < 0.05), group B and C (t = 7.97, P < 0.05), group C and E (t = 4.51, P < 0.05). PT-PCR assays showed the relative expression of SP mRNA in ipsilateral conjunctival tissues of group A~E was (1.00 ± 0.04), (1.61 ± 0.09), (1.26 ± 0.03), (1.27 ± 0.06), (1.08 ± 0.05), respectively. There was statistically significant difference between group A and B (t = -22.04, P < 0.05), group B and C (t = 12.93, P < 0.05), group C and E (t = 11.85, P < 0.05). The expression of tryptase of ipsilateral conjunctiva was (1.00 ± 0.01), (1.01 ± 0.05), (1.02 ± 0.17), (1.00 ± 0.14), (1.01 ± 0.20), and the expression of MBP1 was (1.00 ± 0.03), (1.02 ± 0.15), (0.94 ± 0.08), (1.01 ± 0.07), (0.98 ± 0.13) in A~E groups. There was not statistically significant difference among five groups (F value was 1.93, 0.57, both P > 0.05).

CONCLUSIONSHistamine nasal provocation induced allergic inflammatory response of ipsilateral conjunctiva in guinea pigs. Neural factors including NANC nerves and its medium SP participated this nose-ocular reflex process. These data help to develop a more scientific clinical treatment strategy.

Animals ; Conjunctiva ; physiopathology ; Conjunctivitis, Allergic ; chemically induced ; metabolism ; Eosinophils ; cytology ; Guinea Pigs ; Histamine ; adverse effects ; Male ; Mast Cells ; cytology ; Neurons ; cytology ; Substance P ; metabolism ; Tryptases

INTRODUCTIONIn this study, we have developed and optimised a novel gelatin-chitosan (GC) substrate for use as a cellular carrier for tissue-engineered conjunctival epithelium.

MATERIALS AND METHODSThe substrate was fabricated by casting and the mechanical properties of the substrate, including tensile strength and elongation, were measured. Using the MTT, cell proliferation assay with rabbit conjunctival fibroblasts, we optimised the G:C ratio to enhance cytocompatibility. Rabbit conjunctival epithelial cells were immunostained using monoclonal antibodies for keratin 4 and pancytokeratin to investigate the biological effects of the GC substrate on the proliferation and differentiation of epithelial cells.

RESULTSWe found that increasing the amount of gelatin resulted in an increase in elasticity (from 1:9 to 1:1 ratio), reaching a maximum (101.89% +/- 7.13%) at a ratio of 1:1. The MTT assay showed that the proliferation of conjunctival fibroblasts significantly increased from 0.068 +/- 0.017 to 0.177 +/- 0.011 (P = 0.014) as the gelatin was increased from 20% (1:4) to 50% (1:1). Additional studies using tissue-cultured conjunctiva explants showed that these explants grew well on the substrate, forming a multilayered epithelium. Cell morphology on this substrate was similar to that of cells grown on culture dishes alone. Positive staining of keratin 4 and pancytokeratin indicated that the substrate supported normal differentiation of conjunctival epithelial cells.

CONCLUSIONBy enhancing the proportion of gelatin, both the mechanical and biological properties of the chitosan substrate were improved. The results also suggest that this GC biomembrane may be a useful candidate for reconstructive tissue engineering of the conjunctiva.

Animals ; Biocompatible Materials ; Cell Proliferation ; Cells, Cultured ; Chitosan ; Conjunctiva ; cytology ; metabolism ; physiology ; Elasticity ; Epithelium ; physiology ; Gelatin ; Keratins ; metabolism ; Rabbits ; Tensile Strength ; Tissue Engineering

PURPOSE: To investigate the short-term efficacy of topical immunosuppressive agents on the survival of cultivated allo-conjunctival equivalents. METHODS: Twenty-five eyes of New Zealand white rabbits were included. Temporal conjunctivae were trephined to a diameter of 7.5 mm, and then cultured allo-conjunctival epithelial cells on amniotic membrane were transplanted onto them. Various immunosuppressants including steroid, cyclosporine, and rapamycin were applied topically four times a day for a week. Epithelial defects and graft edema were graded daily. Numbers of inflammatory cells were measured in H&E. PKH26 and cytokeratin 4 and 7 were immunostained. RESULTS: Earlier epithelialization was observed in 1% steroid-treated eyes and defects persisted significantly in 0.5% CsA applied eyes. In histology, PKH26 positive cells considered as donor cells were only found in 1% steroid or 0.01% rapamycin applied eyes. 1% steroid- or 0.01% rapamycin-applied eyes both showed positive staining for keratin-4 and -7. Inflammatory cells were less found in 1% steroid or 0.01% rapamycin treated eyes. CONCLUSIONS: Topical steroid or rapamycin can help to suppress acute inflammation and enhance the acute survival of transplanted conjunctival cells.
Administration, Topical ; Animals ; Cell Count ; *Cell Transplantation ; Cells, Cultured ; Conjunctiva/*cytology ; Cyclosporine/pharmacology ; Epithelial Cells/metabolism/*transplantation ; Female ; Fluorescent Antibody Technique, Indirect ; Graft Survival/*drug effects ; Immunosuppressive Agents/*pharmacology ; Keratin-4/metabolism ; Keratin-7/metabolism ; Male ; Organic Chemicals/metabolism ; Prednisone/pharmacology ; Rabbits ; Sirolimus/pharmacology ; Transplantation, Homologous