apyrase and Atrophy

Loss of retinal capillaries is an inherent component of late stage autosomal dominant retinitis pigmentosa (ADRP). This study examined the hypothetical role of tissue hyperoxia in this vascular attenuation process and tested the potential of ambient hypoxia to reverse it.. Transgenic mice expressing a mutant opsin gene with a 3-bp deletion of isoleucine at codon 255/256 were used. This model is characterized by early onset of a rapidly progressing retinal degeneration that by postnatal day (P)20 results in the loss of all but one row of photoreceptor nuclei. At P20 some mice were placed in 12% oxygen until they were euthanatized at P26. The remainder were maintained in normoxia and killed at the same age. Retinas were dissected, stained for ADPase, and flat-mounted.. Deep plexus capillary density was significantly different in normoxic normals versus transgenics at 20 days of age (P:

Topics: Animals; Apyrase; Atrophy; Capillaries; Cell Death; Disease Models, Animal; Female; Hypoxia; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Photoreceptor Cells, Vertebrate; Retinal Vessels; Retinitis Pigmentosa; Rod Opsins

Four groups of BALB/c mice were treated locally with different concentrations (0.1-1.0%) of retinoic acid (Etretinate) ointment for a period of one to four weeks. A fifth group was treated with the ointment base only. Ia-positive dendritic cells were identified by an indirect immunofluorescence technique which was confirmed by ADPase staining. Quantitative counts of Langerhans cells were performed for each group. After four weeks, the 0.1 and 0.2% Etretinate-treated conjunctiva showed no significant reduction in Langerhans cell concentration. However, following 0.5 and 1.0% Etretinate treatment for four weeks, the concentration of Langerhans cells was significantly reduced, and the cells showed morphologic changes, consisting mainly of loss of dendritic processes. Between one and two weeks of therapy at these two high concentrations, no significant changes were found. Light microscopy of the conjunctival epithelium showed marked atrophic changes following four weeks of 0.5 and 1.0% Etretinate treatment compared to no changes with 0.1 and 0.2% Etretinate treatment.

Topics: Administration, Topical; Animals; Apyrase; Atrophy; Cell Count; Conjunctiva; Epithelium; Etretinate; Fluorescent Antibody Technique; Histocompatibility Antigens Class II; Langerhans Cells; Mice; Mice, Inbred BALB C; Ointments