scholarly journals Structural and Functional Change in Albino Rat Retina Induced by Various Visible Light Wavelengths

2021 ◽  
Vol 23 (1) ◽  
pp. 309
Author(s):  
Sachiko Kaidzu ◽  
Tsutomu Okuno ◽  
Masaki Tanito ◽  
Akihiro Ohira

The effects of visible light, from short to long wavelengths, on the retina were investigated functionally and histologically. The left eyes of Sprague–Dawley albino rats (6-weeks old, n = 6 for each wavelength) were exposed to seven narrow-band wavelengths (central wavelengths, 421, 441, 459, 501, 541, 581, and 615 nm) with bandwidths of 16 to 29 nm (half bandwidth, ±8–14.5 nm) using a xenon lamp source with bandpass filters at the retinal radiant exposures of 340 and 680 J/cm2. The right unexposed eyes served as controls. Seven days after exposure, flash electroretinograms (ERGs) were recorded, and the outer nuclear layer (ONL) thickness was measured. Compared to the unexposed eyes, significant reductions in the a- and b-wave ERG amplitudes were seen in eyes exposed to 460-nm or shorter wavelengths of light. The ONL thickness near the optic nerve head also tended to decrease with exposure to shorter wavelengths. The decreased ERG amplitudes and ONL thicknesses were most prominent in eyes exposed to 420-nm light at both radiant exposures. When the wavelengths were the same, the higher the amount of radiant exposure and the stronger the damage. Compared to the unexposed eyes, the a- and b-waves did not decrease significantly in eyes exposed to 500-nm or longer wavelength light. The results indicate that the retinal damage induced by visible light observed in albino rats depends on the wavelength and energy level of the exposed light.

Author(s):  
E.A. Kapustina ◽  
L.G. Lisetskaya

Introduction. Lead pollution is a common environmental problem. Having no physiological functions, this toxicant has a negative polytropic impact on a body, including neurotoxic, reproductive, and transgenerational effects. The mechanism of lead toxicity is oxidative stress. Flavonoids have active antioxidant properties. They are widely represented in plant foods, are able to restore protective capabilities of cells and have chelating properties with respect to lead. One of the representatives of this group of substances is dihydroquercetin. The objective was to study the effect of dihydroquercetin on behavior of rats with hereditary chemical body burden exposed to lead at 60 mg/kg during 25 days. Materials and methods. We studied the behavior of rat offspring in an open field and established their blood lead levels by electrothermal atomization atomic absorption spectrometry. For statistical processing the U-Mann – Whitney test was used. Results. In the present experiment, the effect of lead on the offspring of male albino rats exposed to 60 mg/kg of lead for 25 days caused changes in the activity of animals in the open field. The severity of changes was more pronounced in animals with a hereditary chemical body burden. These animals showed a decrease in orientation and physical activity and increased anxiety. In rats with a hereditary burden, changes in behavior were detected when administering dihydroquercetin. The activity of animals demonstrated a positive dynamics: we observed a statistically significant increase in physical activity and orientation. The number and duration of behavioral acts approached control values. Conclusions. The revealed effects of lead on the offspring of albino rats with a transgenerational chemical body burden require further study to understand the mechanism of the phenomenon.


Author(s):  
Dhaval Gohil ◽  
Nasser Mohammed ◽  
Anita Mahadevan ◽  
Nupur Pruthi

Abstract Objective To compare the histopathology of patent and nonpatent microvascular anastomosis using rat femoral artery end-to-end anastomosis model. Materials and Methods In 15 Sprague–Dawley rats, end-to-end anastomosis was performed on the right femoral artery. The classical method was used in four cases and one-way up method in 11 cases. The animals were sacrificed after 2 weeks and the anastomosis was subjected to histopathology. The pathological changes in patent and nonpatent cases were compared. Results The immediate patency rate and delayed patency (after 2 weeks) rate was 86.7% and 66.7%, respectively. The mean follow-up was 3 months. At sacrifice, 5/15 anastomosis were not patent. Marked subintimal thickening was noted in ⅘ (80%) of the nonpatent group, which was absent in the patent group. Severe loss or fibrosis of tunica media and marked adventitial inflammation were noted in all nonpatent cases (5/5, 100%). As much as ⅘ of the nonpatent cases had poor or indeterminate apposition; in contrast, good apposition was seen in 6/10 (60%) of the patent group. The mean clamp time and mean suturing time were significantly longer in the nonpatent group (69.2 minutes and 53.8 minutes, respectively) as compared with the patent group (48.8 minutes and 31.8 minutes, respectively). A single case that was initially nonpatent was found to have recanalized at 6 months. Conclusion Minimal intimal injury and reaction, minimal thinning of tunica media, mild-to-moderate adventitial changes, good apposition, and equidistant sutures were associated with a successful microvascular anastomosis. Short duration of vessel clamping time and suturing comes with experience and dedicated practice in a skills laboratory.


Author(s):  
Yun-Hee Kim ◽  
Sung-Uk Choi ◽  
Jung-Min Youn ◽  
Seung-Ha Cha ◽  
Hyeon-Ju Shin ◽  
...  

BACKGROUND: The prevention of rheologic alterations in erythrocytes may be important for reducing sepsis-associated morbidity and mortality. Remote ischemic preconditioning (RIPC) has been shown to prevent tissue damage caused by severe ischemia and mortality resulting from sepsis. However, the effect of RIPC on erythrocytes in sepsis is yet to be determined. OBJECTIVE: To investigate the effect of RIPC on rheologic alterations in erythrocytes in sepsis. METHODS: Thirty male Sprague-Dawley rats were used in this study. An endotoxin-induced sepsis model was established by intraperitoneally injecting 20 mg/kg LPS (LPS group). RIPC was induced in the right hind limb using a tourniquet, with three 10-minute of ischemia and 10 min of reperfusion cycles immediately before the injection of LPS (RIPC/LPS group) or phosphate-buffered saline (RIPC group). The aggregation index (AI), time to half-maximal aggregation (T1/2), and maximal elongation index (EImax) of the erythrocytes were measured 8 h after injection. RESULTS: The AI, T1/2, and EImax values in the LPS and RIPC/LPS groups differed significantly from those in the RIPC group, but there were no differences between the values in the LPS and RIPC/LPS groups. CONCLUSIONS: RIPC did not prevent rheologic alterations in erythrocytes in the rat model of LPS-induced endotoxemia.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Emmanouil Chatzipetros ◽  
Spyros Damaskos ◽  
Konstantinos I. Tosios ◽  
Panos Christopoulos ◽  
Catherine Donta ◽  
...  

Abstract Background This study aims at determining the biological effect of 75/25 w/w nano-hydroxyapatite/chitosan (nHAp/CS) scaffolds on bone regeneration, in terms of fraction of bone regeneration (FBR), total number of osteocytes (Ost), and osteocyte cell density (CD), as well as its biodegradability. Methods Two critical-size defects (CSDs) were bilaterally trephined in the parietal bone of 36 adult Sprague-Dawley rats (18 males and 18 females); the left remained empty (group A), while the right CSD was filled with nHAp/CS scaffold (group B). Two female rats died postoperatively. Twelve, 11, and 11 rats were euthanized at 2, 4, and 8 weeks post-surgery, respectively. Subsequently, 34 specimens were resected containing both CSDs. Histological and histomorphometric analyses were performed to determine the FBR, calculated as [the sum of areas of newly formed bone in lateral and central regions of interest (ROIs)]/area of the original defect, as well as the Ost and the CD (Ost/mm2) in each ROI of both groups (A and B). Moreover, biodegradability of the nHAp/CS scaffolds was estimated via the surface area of the biomaterial (BmA) in the 2nd, 4th, and 8th week post-surgery. Results The FBR of group B increased significantly from 2nd to 8th week compared to group A (P = 0.009). Both the mean CD and the mean Ost values of group B increased compared to group A (P = 0.004 and P < 0.05 respectively). Moreover, the mean value of BmA decreased from 2nd to 8th week (P = 0.001). Conclusions Based on histological and histomorphometric results, we support that 75/25 w/w nHAp/CS scaffolds provide an effective space for new bone formation.


1965 ◽  
Vol 16 (3) ◽  
pp. 693-696 ◽  
Author(s):  
L. Glenn Collins

In two experiments involving 40 albino rats and two dosage levels of morphine sulfate it was found that relatively high analgesic dosages of morphine significantly depressed general activity level in the revolving drum. Also, there was a significant interaction between drug effect and hunger drive. In the case of moderate analgesic doses (7 mg/kg) no systematic effect of morphine on activity-wheel performance was noted.


1953 ◽  
Vol 98 (1) ◽  
pp. 71-80 ◽  
Author(s):  
George R. Meneely ◽  
Robert G. Tucker ◽  
William J. Darby ◽  
Stewart H. Auerbach

Sustained arterial hypertension developed in male, albino rats chronically fed diets rich in sodium chloride with demineralized drinking water available ad libitum. After 12 months of the experimental regimen a positive, linear correlation (r = 0.91) was found between the systolic blood pressure and the concentration of sodium chloride in the diet. A syndrome of edema and renal failure was observed in 18 per cent of the group fed at the level of 7.0 to 9.8 per cent of sodium chloride. Significant histologic changes occurred in the kidneys and certain other organs in rats consuming rations containing these levels of NaCl. The relative volume of the radiosodium space was increased in the rat by high dietary sodium chloride.


1992 ◽  
Vol 9 (3-4) ◽  
pp. 409-414 ◽  
Author(s):  
Pilar Herreros De Tejada ◽  
Daniel G. Green ◽  
Carmen Muñoz Tedó

AbstractAlbino rats have recently been reported to have increment thresholds against dim backgrounds that are two log units higher than those of pigmented rats. We, on the other hand, have failed to confirm these differences using electroretinogram b waves and pupillary light reflexes. This paper reports on experiments using evoked potentials from cortex and colliculus and single-unit recordings from colliculus.We recorded visual-evoked potentials from cortex and superior colliculus in the strains of albino (CD) and pigmented (Long-Evans) rats used in the earlier studies. Thresholds were determined on eight fully dark-adapted animals by extrapolating intensity-response curves to the point at which there was zero evoked potential. The average dark-adapted threshold for the visual-evoked cortical potential was —5.26 log cd/m2in pigmented and —5.80 log cd/m2 in albino animals. The average dark-adapted threshold for the superior colliculus evoked response was —5.54 log cd/m2 in pigmented and —5.84 log cd/m2 in albinos. The differences were not statistically significant. On the same apparatus, the average absolute threshold for three human observers was —5.3 log cd/m2, a value close to the rat dark-adapted thresholds. Thus, visual-evoked cortical potentials and superior collicular evoked potentials failed to confirm the report of higher dark-adapted thresholds for albinos. In addition, we find that single units in superior colliculus in the albino rat respond to very dim flashes.


1963 ◽  
Vol 205 (3) ◽  
pp. 453-456 ◽  
Author(s):  
Philip D. Gollnick

Two groups of male albino rats of the Sprague-Dawley strain, with average initial body weights of about 265 g, were trained for 22 weeks on an exercise program of swimming one-half hour daily in water at 35 C. One trained group was fed a normal diet containing 18% casein. The other trained group received an isocaloric diet containing 1% cholesterol which was designed to produce hypercholesteremia. Two nonexercised groups, one fed the normal and the other the 1% cholesterol diet, served as controls. The adrenals and heart ventricles of both trained groups were larger than their respective controls. Exercise had no hypocholesteremic effect on the sera of either trained group. Fat and cholesterol accumulation in the livers of rats fed the 1% cholesterol diet were not affected by training, but training significantly lowered the fat and cholesterol of the livers of the normal rats.


2005 ◽  
Vol 24 (6) ◽  
pp. 451-467 ◽  
Author(s):  
Raymond G. York ◽  
John Barnett ◽  
Michael F. Girard ◽  
David R. Mattie ◽  
Marni V. K. Bekkedal ◽  
...  

A developmental neurotoxicity study was conducted to generate additional data on the potential functional and morphological hazard to the central nervous system caused by ammonium perchlorate in offspring from in utero and lactation exposure. Female Sprague-Dawley rats (23 to 25/group) were given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 10.0 mg/kg-day perchlorate in the drinking water beginning 2 weeks prior to mating and continuing through day 10 of lactation for the behavioral function assessment or given continuous access to 0 (carrier), 0.1, 1.0, 3.0, and 30.0 mg/kg-day beginning on gestation day 0 and continuing through day 10 of lactation for neurodevelopment assessments. Motor activity was conducted on postpartum days 14, 18, and 22 and juvenile brain weights, neurohistopathological examinations, and regional brain morphometry were conducted on postpartum days 10 and 22. This research revealed a sexually dimorphic response, with some brain regions being larger in perchlorate-treated male rats than in comparable controls. Even so, there was no evidence of any obvious exposure-related effects on male rat brain weights or neuropathology. The most consistent exposure-related effect in the male pups was on the thickness of the corpus callosum, with both the right- and left-sided measures of the thickness of this white matter tract being significantly greater for the male pups in the 0.1 and 1.0 mg/kg-day exposure groups. The behavioral testing suggests prenatal exposure to ammonium perchlorate does not affect the development of gross motor movements in the pups.


1982 ◽  
Vol 243 (2) ◽  
pp. H296-H306 ◽  
Author(s):  
M. H. Laughlin ◽  
R. B. Armstrong

Muscle blood flow (BF) was measured using the radiolabeled microsphere technique within and among nine major muscles of rats before exercise and during treadmill walking or running at speeds of 15, 30, 45, 60, and 75 m/min. Measurements were made during exercise after 1 min of steady walking or running. Male Sprague-Dawley rats were chronically instrumented with 2 Silastic catheters, one in the ascending aorta via the right carotid artery for microsphere infusion and one in the left renal artery for arterial reference blood sample withdrawal. The preexercise results demonstrated that 1) BF to deep slow-twitch muscles was three to four times that to peripheral fast muscles (e.g., soleus and gastrocnemius BFs were 138 and 33 ml . min-1 . 100 g-1, respectively); 2) BFs to red portions within mixed muscles were three to four times those to white portions (e.g, red and white gastrocnemius BFs were 54 and 18 ml . min-1 . 100 g-1, respectively; and 3) there was a direct relationship (P less than 0.05) between BFs to muscles and their slow-twitch oxidative fiber populations. The results obtained during exercise demonstrated that 1) at the slowest speed studied (15 m/min) BFs to the red portions of muscles increased, whereas BFs to the white portions of the same muscles decreased; 2) BFs to all muscles (except soleus) were increased during running at 75 m/min when there was a range of flows of 30 ml . 100 g-1 . min-1 (white gastrocnemius) to 321 (vastus intermedius), 3) at all running speeds the increases in BF to muscles were directly related to the fast-twitch, high-oxidative fiber populations of the muscles; and 4) BFs to visceral tissues and fat were decreased during exercise.


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