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Not AvailableTambraparni barb is one of the endangered barb variety from Western Ghats, which was successfully domesticated and bred at ICAR-Central Institute of Freshwater Aquaculture, Bhubaneswar, India. It has a global ornamental potential in planted aquarium and are exported to many nations from the wild. An experiment was conducted for 45 days to estimate the optimum quantity of Hydrilla plant required for better growth and survival of tambraparni barb. Three-month old juveniles having length and weight 20.2±0.5 mm and 296±25 mg, respectively are reared in FRP tanks of 360 litres water holding capacity (120×60×50 cm3) without providing aeration. Four treatments with different quantities of Hydrilla, viz. 0.25 kg, 0.5 kg, 1 kg, 1.5 kg and a control tank without Hydrilla was taken and 25 number of fishes were stocked per tank. The fishes were fed with a commercial feed ad libitum. The present study concludes that the optimum requirement of Hydrilla plant required for successful rearing of tambraparni barb with significantly better growth and survival is 0.5-1 kg Hydrilla, may be suggested for rearing as it provides better shelter and environment.Not Availabl

PBN (Phenyl-N-Tert-Butylnitrone)-Derivatives Are Effective in Slowing the Visual Cycle and Rhodopsin Regeneration and in Protecting the Retina from Light-Induced Damage.

A2E and related toxic molecules are part of lipofuscin found in the retinal pigment epithelial (RPE) cells in eyes affected by Stargardt's disease, age-related macular degeneration (AMD), and other retinal degenerations. A novel therapeutic approach for treating such degenerations involves slowing down the visual cycle, which could reduce the amount of A2E in the RPE. This can be accomplished by inhibiting RPE65, which produces 11-cis-retinol from all-trans-retinyl esters. We recently showed that phenyl-N-tert-butylnitrone (PBN) inhibits RPE65 enzyme activity in RPE cells. In this study we show that like PBN, certain PBN-derivatives (PBNDs) such as 4-F-PBN, 4-CF3-PBN, 3,4-di-F-PBN, and 4-CH3-PBN can inhibit RPE65 and synthesis of 11-cis-retinol in in vitro assays using bovine RPE microsomes. We further demonstrate that systemic (intraperitoneal, IP) administration of these PBNDs protect the rat retina from light damage. Electroretinography (ERG) and histological analysis showed that rats treated with PBNDs retained ~90% of their photoreceptor cells compared to a complete loss of function and 90% loss of photoreceptors in the central retina in rats treated with vehicle/control injections. Topically applied PBN and PBNDs also significantly slowed the rate of the visual cycle in mouse and baboon eyes. One hour dark adaptation resulted in 75-80% recovery of bleachable rhodopsin in control/vehicle treated mice. Eye drops of 5% 4-CH3-PBN were most effective, inhibiting the regeneration of bleachable rhodopsin significantly (60% compared to vehicle control). In addition, a 10% concentration of PBN and 5% concentration of 4-CH3-PBN in baboon eyes inhibited the visual cycle by 60% and by 30%, respectively. We have identified a group of PBN related nitrones that can reach the target tissue (RPE) by systemic and topical application and slow the rate of rhodopsin regeneration and therefore the visual cycle in mouse and baboon eyes. PBNDs can also protect the rat retina from light damage. There is potential in developing these compounds as preventative therapeutics for the treatment of human retinal degenerations in which the accumulation of lipofuscin may be pathogenic

Histological analysis of rat retina confirms protection from light damage.

<p>Vehicle or Saline treated (Vehicle LD) rats lost most of their photoreceptors from the central retina. Effect is more pronounced in the superior retina. NLD is non-light-damage control. Fig 4A shows the ONL thickness across the retina in the vertical meridian. PBN treatment (PBN LD) retinas retained ~90% of photoreceptor cells. 4-CF₃-PBN is comparable to PBN in protection, whereas 4-F-PBN appears better than PBN. 4-CH₃-PBN also protects the retina significantly, although its effect is slightly less than PBN. Fig 4B shows central retinal outer retinal layer (ONL) thickness in both inferior and superior retina. [** = <i>p</i><0.001; <i>n</i> = 8–10]</p

PBN and certain PBNDs inhibited rhodopsin regeneration.

<p>Rats were treated with either PBN or certain PBNDs before 2h of light adaptation followed by 2.5h of dark adaptation after which the animals were euthanized and retinas harvested for rhodopsin assay. Saline treated retina recovered ~ 75% rhodopsin in 2.5h dark. PBN and its derivatives, however, blocked rhodopsin regeneration significantly. LA, light adapted; DA, dark adapted. [* = <i>p</i><0.01; ** = <i>p</i><0.001; <i>n</i> = 4–6]</p

PBND tested for RPE-65 enzyme inhibition efficiency.

<p>The structure of PBN and the derivatives of PBN that are used in various <i>in vitro</i> and <i>in vivo</i> assays are shown in Fig 1A–1D. Concentration-dependent inhibition of RPE65 and generation of 11-<i>cis</i>-retinol in <i>in vitro</i> microsome assays were performed with representative images shown in Fig 1E, 4-F-PBN; Fig 1F, 4-CF₃-PBN; and Fig 1G, 4-CH₃-PBN. A table of the IC₅₀ values of the compounds tested for their inhibition efficiency for RPE 65, (Fig 1J), show various inhibition rates for which we determined which PBN-derivatives looked the most promising to continue our analysis.</p

Systemically administered PBN and PBND protect rat retina from light damage.

<p>Electroretinographic (ERG) responses were recorded for a series of flash stimuli intensities at 0.04, 4, 200, 400, and 2000 cd.sec/m². ERG responses presented here are from the intensities of 4 and 400 cd.sec/m². The dim flash (4 cd.sec/m²) stimulates the rod photoreceptor cells and the bright flash (400 cd.sec/m²) stimulates both rod and cone photoreceptors. Therefore, the blue bars represent only rod responses and the red bars represent mixed response from both rod and cone photoreceptors. Fig 3A shows A-wave responses, and Fig 3B shows B-wave responses. NLD represents non-light-damaged group and LD represents light-damaged groups. [## = <i>p</i><0.001: NLD vs. LD saline-treated; * = <i>p</i><0.01 and ** = <i>p</i><0.001: LD saline vs. PBNDs; <i>n</i> = 4–6]</p

PBN and 4-CH₃-PBN topically administered in baboon eyes slows rate of rhodopsin regeneration.

<p>Baboon eyes were treated topically with drug or vehicle every 15 minutes over a 2h period before eyes were harvested and dark adapted 2h before retinal harvest. 10% PBN showed a roughly 50% higher inhibition rate compared to 5% CH₃-PBN suggesting both drugs to be effective. [** = <i>p</i><0.001; <i>n</i> = 6–8 eyes]</p