Classification, location, and intensity of granules in retinal pigment epithelium following sodium iodate injection in rat animal model

Objectives

Age-related macular degeneration (AMD) is one of the eye diseases that can affect a person's central vision. Retinal pigment epithelium (RPE) cells are damaged in this medical condition and some pigments are presented in these cells. Here, we aimed to investigate melanin and lipofuscin granules of RPE cells as a precursor of AMD.

Materials and Methods

Hooded rats (n=18) were divided into two groups and received 100 μl of sodium iodate (SI) into the retro-orbital sinus of their eyes at 40 and 60 mg/kg doses. The total number of melanin and lipofuscin granules, different types of granules, cytoplasmic dispersion of granules as well as morphological changes in the shape and number of nuclei of RPE cells were evaluated over the course of 1-30 days.

Results

The total number of melanin pigments increases over time at a dose of 40 mg/kg and decreases at a dose of 60 mg/kg. Also, the total number of lipofuscin granules in 40 mg/kg increases over time and decreases in 60 mg/kg. Autofluorescent intensity (AF) is also increased at 40 mg/kg, but at 60 mg/kg, the highest intensity is on day 7. Also, the highest number of multinucleated giant cells was on day 7 at 60 mg/kg and the most changes in cell appearance due to sodium iodate injection were seen on the first day after injection.

Conclusion

We demonstrated that granules and autofluorescent intensity appear to decrease at high doses of sodium iodate, which is similar to the advanced stage of the AMD disease, where the number of granules and AF intensity increase in the middle and even early stages of the disease.

Effects of Low-Intensity Continuous Ultrasound on Hematological Parameters of Rats

BACKGROUND

Low intensity ultrasound (US) has some well-known bio-effects which are of great importance to be considered. Objective: We conducted the present study to investigate the effects of low intensity continuous ultrasound on blood cells count in rat.

METHODS

Rats were anesthetized and blood samples were collected before US exposure. Then, they were exposed to US with nominal intensity of 0.2 W/cm2 at frequency of 3 MHz for a period of 10 minutes and this protocol was repeated for 7 days. Twenty four hours after the last US exposure, secondary blood samples were collected and the changes in blood parameters were evaluated.

RESULTS

Analysis revealed that platelets, hematocrit (HCT) and hemoglobin (HGB) were significantly different between experimental and sham groups but no difference between sham and control groups was observed. The results show that HCT and HGB of exposed rats were significantly reduced. Conclusion: This study shows that low intensity US may lead to side effects for hematological parameters such as reduction in the levels of HGB and HCT.