scholarly journals A New Spontaneously Diabetic Non-obese Torii Rat Strain With Severe Ocular Complications

2000 ◽  
Vol 1 (2) ◽  
pp. 89-100 ◽  
Author(s):  
Masami Shinohara ◽  
Taku Masuyama ◽  
Toshiyuki Shoda ◽  
Tadakazu Takahashi ◽  
Yoshiaki Katsuda ◽  
...  

A new spontaneously diabetic strain of the Sprague-Dawley rat was established in 1997 and named the SDT (Spontaneously Diabetic Torii) rat. In this research, we investigated the characteristics of the disease condition in the SDT rats. The time of onset of glucosuria was different between male and female SDT rats; glucosuria appeared at approximately 20 weeks of age in male rats and at approximately 45 weeks of age in female rats. A cumulative incidence of diabetes of 100% was noted by 40 weeks of age in male rats, while it was only 33.3% even by 65 weeks of age in female rats. The survival rate up to 65 weeks of age was 92.9% in male rats and 97.4% in female rats. Glucose intolerance was observed in male rats from 16 weeks of age. The clinical characteristics of the male SDT rats were (1) hyperglycemia and hypoinsulinemia (from 25 weeks of age); (2) long-term survival without insulin treatment; (3) hypertriglyceridemia (by 35 weeks of age); however, no obesity was noted in any of the male rats. The histopathological characteristics of the male rats with diabetes mellitus (DM) were (1) fibrosis of the pancreatic islets (by 25 weeks of age); (2) cataract (by 40 weeks of age); (3) tractional retinal detachment with fibrous proliferation (by 70 weeks of age) and (4) massive hemorrhaging in the anterior chamber (by 77 weeks of age). These clinical and histopathological characteristics of the disease in SDT rats resemble those of human Type 2 diabetes with insulin hyposecretion. In conclusion, SDT rat is considered to be a potentially useful model for studies of diabetic retinopathy encountered in humans.

1984 ◽  
Vol 3 (6) ◽  
pp. 469-483 ◽  
Author(s):  
W. Sontag

1 Female and male rats of the Sprague-Dawley strain, aged about 13 months, were injected intravenously with monomeric 239Pu-(30.7 kBq/kg), 241Am-(54.8 kBq/kg) or 233U-citrate (56.6 kBq/kg) and killed between 7 and 540 days after injection. 2 In both sexes the wet skeletal weight was proportional to body weight; however, the skeletal weight of female rats remained constant, whereas the skeletal weight, and body weight, of male rats increased as a function of age. 3 The initial skeletal deposition decreased in the order 239Pu > 241Am > 233U and for americium and uranium was greater in male rats. The 'half-time' of retention of plutonium and americium was considerably greater than 1 year but the corresponding values for uranium were 140 (females) and 80 (males) days. 4. The relative concentration of the radionuclides in the skeleton varied between 0.2 and 2.0, the variation was greatest for plutonium and lowest for americium and decreased with increasing time after injection. 5 For calculation of the nuclide content of the whole skeleton the most suitable reference bone was found to be the humerus in the case of uranium, and the femur and humerus for plutonium and americium. 6 The cumulative mean skeletal absorbed radiation dose 1 year after injection decreased in the order 239Pu > 241 Am > 233U; for plutonium it was equal for both sexes, whereas for americium and uranium it was 1.5 times higher in male than in females rats. In the individual bones the cumulative dose was greatest in the vertebral column, except the tail, and lowest in the paws.


2021 ◽  
Vol 28 (4) ◽  
pp. 33-39
Author(s):  
L. G. Voronkov ◽  
N. A. Tkach ◽  
O. L. Filatova ◽  
T. I. Gavrilenko

The aim – to determine the predictors of 5-year survival of patients with CHF and reduced LV EF depending on the presence of type 2 diabetes mellitus.Materials and methods. 490 case histories of patients in the period from 2011 to 2018 with CHF, 40–80 years of age (median – 64 years), II–IV NYHA functional class, LVEF ≤ 40 % were analyzed. For the analysis of all patients with CHF and reduced LV EF were divided into two groups: Group I included 338 (69 %) patients without diabetes mellitus type 2, group II consisted of 152 (31 %) patients diagnosed with diabetes mellitus type 2. To measure the values ​​of the independent predictors, we calculated the value of the odds ratio (OR) with a 95 % confidence interval. To determine predictors of mortality/survival of the studied patients, was calculated the Хі-square criterion. Additionally, we calculated the estimate of the frequency difference between the groups, the odds ratio, the confidence interval for the odds ratio, the Pearson correlation coefficient r, for all the calculated characteristics we determined the probability of error of the first kind p. As a result, we formed a final table of indicators-predictors of mortality/survival of patients with CHF with reduced LV EF with and without diabetes mellitus type 2 for which there is a statistical relationship between mortality / survival and the studied indicator.Results and discussion. In patients without diabetes, many indicators are associated with the prognosis of long-term survival. These include hemodynamic parameters (heart rate, the left atrium size (LV) and indexed left ventricular (LV) volumes, LV myocardial mass index, right ventricular size (RV) and LV ejection fraction, renal function parameters (microalbuminuria (UIA), glomerular filtration rate (GFR), urea nitrogen), systemic inflammatory marker (C-reactive protein (CRP)), markers of systemic oxidative stress (myeloperoxidase, citrulline, uric acid) and antioxidant defence – SOD, as well as the N-terminal fragment of the precursor of natriuretic peptide (NT-proBNP), flow-dependent vasodilatory response (FDVR), high-density lipoprotein cholesterol (HDL), insulin and the relative content of lymphocytes in the blood. Patients with diabetes had significantly fewer such predictors: in addition to parameters of intracardiac hemodynamics and heart modeling, other significant predictors of 5-year survival were daily UIA level, CRP, SOD, HDL, insulin and the lymphocyte level.Conclusions. Quantitative predictors of poor 5-year survival prognosis among patients with CHF and reduced LV EF with and without concomitant diabetes mellitus type 2 are parameters of heart remodeling, LV systolic function-EF, UIA level, antioxidant stress marker (SOD), HDL level, blood lymphocytes and the level of circulating insulin. Patients without diabetes are characterized by a wider range of poor long-term survival predictors, which include indicators of renal nitrogen function, markers of systemic oxidative stress (myeloperoxidase, citrulline, uric acid), flow-dependent vasodilatory response and circulating NT-proBNP. The determined quantitative predictors can be used in algorithms of individual prediction of the course of CHF and reduced LV EF, which should be created separately for patients with and without concomitant diabetes mellitus type 2


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Nildris Cruz Diaz ◽  
A'ja V Duncan ◽  
Wayne Graham ◽  
Brian Westwood ◽  
Patricia E. Gallagher ◽  
...  

Physical performance and systolic blood pressure (SBP) during aging in normotensive female Sprague-Dawley (SD) and hypertensive (mRen2)27 transgenic rats were assessed following long-term treatment with a Muscadine Grape Extract (MGE, Piedmont Research and Development Corp). MGE was administered at a dose of 0.2 mg/mL in the drinking water starting at 14 weeks (wks) of age with an endpoint at 70 wks of age (total time of treatment of 56 wks). At 20-, 40- and 70-wks of age, physical performance (exercise capacity in seconds and workload in grams - meters) was determined using a treadmill at a velocity of 17 cm/second with a 5% incline. SBP was determined by tail-cuff plethysmography in trained rats. There were no significant differences in physical performance between SD and (mRen2)27 female rats at any age despite the higher SBP in the (mRen2)27 rats at all ages. Long-term treatment with MGE had no significant effect on physical performance or SBP in SD rats at any age. In contrast, MGE treatment markedly increased exercise capacity (40 wks: 1615 ± 166 vs 4943 ± 442 seconds, p<0.01, n = 4-9; 70 wks: 2520 ± 374 vs 4117 ± 245 seconds, p<0.01, n = 4-8) and workload (40 wks: 4579 ± 490 vs 14730 ± 1353 grams - meters, p<0.01, n = 4-9; 70 wks: 8338 ± 1340 vs 13659 ± 933 grams - meters, p<0.01, n = 4-8) at the later ages in female (mRen2)27 rats, while there was no effect on SBP (20 wks: 167 ± 4 vs 173 ± 4 mm Hg, n = 4-6; 40 wks: 177 ± 8 vs 170 ± 7 mm Hg, n = 6-7; 70 wks:154 ± 6 vs 172 ± 6 mm Hg, n = 5) at any age. These data suggest that MGE treatment is effective in improving physical performance only in hypertensive female rats and may be independent of changes in blood pressure. The benefit of MGE in the older hypertensive female may reflect reductions in vascular stiffness and oxidative stress. Support: Chronic Disease Research Fund, Hypertension & Vascular Research Center


Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Fatima Ryalat ◽  
N Cruz-Diaz ◽  
W Graham ◽  
T Gwathmey-Williams ◽  
P E Gallagher ◽  
...  

Aldosterone plays a significant role in hypertension and target organ damage. Aldosterone antagonists are used in the management of heart failure. However, neither the influence of age nor sex on aldosterone pathophysiology is well understood. We investigated the changes in circulating aldosterone with age and its association with cardiovascular function, using male and female hypertensive renin transgenic (mRen2)27 rats and SD rats at 20 and 50 weeks of age. Both male (22 ± 3 vs. 12 ± 2 ng/dL, n = 9 - 12, p < 0.05) and female (59 ± 10 vs. 23 ± 8 ng/dL, n = 6 - 10, p < 0.05) hypertensive rats had higher serum aldosterone compared with SD rats at 20 weeks of age. At 50 weeks of age, the difference persisted in the hypertensive female rats (63 ± 8 vs. SD: 33 ± 7 ng/dL, n = 6 - 7, p < 0.05), but not in the males. SD male rats have higher systolic blood pressure (SBP) as they age, and consequently develop cardiac diastolic dysfunction associated with higher aldosterone at 50 weeks compared to 20 weeks (28 ± 3 vs. 12 ± 2 ng/dL, n = 7 - 9, p < 0.05). This aging effect on aldosterone was not significant in the other groups. We showed previously that SD males treated with polyphenol rich muscadine grape extract (MGE) have lower aldosterone, less aortic stiffness and better cardiac diastolic function (E/e’) than controls at the older age; the MGE effect was not seen in (mRen2)27 males. Sex differences in aldosterone were not significant in the SD rats at either time point. However, (mRen2)27 female rats had higher aldosterone than (mRen2)27 males at both 20 weeks (59 ± 10 vs. 22 ± 3 ng/dL, n = 10 - 12, p < 0.05) and 50 weeks (63 ± 8 vs. 31 ± 7 ng/dL, n = 6 - 7, p < 0.05), despite the lack of significant differences in SBP. (mRen2)27 female rats preserve cardiac function better than males throughout their life span, while males develop indices of heart failure. Our data suggest that lower aldosterone levels in hypertensive males compared with females do not protect against the higher lifetime burden of elevated SBP and also may reflect different mechanisms controlling circulating aldosterone between sexes. In addition, data suggest a potential therapeutic effect of MGE in the management of age-associated moderate hypertension.


1991 ◽  
Vol 260 (2) ◽  
pp. H453-H458 ◽  
Author(s):  
J. N. Stallone ◽  
J. T. Crofton ◽  
L. Share

Previously, we reported that, in the rat, pressor responsiveness to vasopressin (VP) is higher in males than in females during most phases of the estrous cycle. To explore the role of the vasculature in this phenomenon, we examined vascular reactivity to VP in thoracic aortas of male rats and female rats during each phase of the estrous cycle. Aortic rings were prepared from age-matched male and female Sprague-Dawley rats and mounted for isometric tension recording. Maximal response of female aortas to VP (4,246 +/- 163 mg/mg ring dry wt) was more than twice (P less than 0.001) that of male aortas (1,877 +/- 215 mg/mg ring wt). Sensitivity of female aortas to VP was substantially higher (P less than 0.001) than that of male aortas (EC50: 10.9 +/- 0.7 vs. 19.0 +/- 1.6 nM, respectively). Maximal rate of tension development (dT/dtmax) during contraction with VP was nearly twofold higher (P less than 0.01) in female aortas (536 +/- 23 mg/min) than in male aortas (300 +/- 19 mg/min). Maximal response, sensitivity, and dT/dtmax of female aortas did not vary significantly during the estrous cycle. Maximal response of female aortas to phenylephrine (PE; 1,251 +/- 93 mg/mg ring wt) was half that (P less than 0.001) of male aortas (2,546 +/- 194 mg/mg ring wt); sensitivity to PE did not differ significantly (EC50: 0.33 +/- 0.02 vs. 0.38 +/- 0.06 microM, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)


2014 ◽  
Vol 59 (No. 9) ◽  
pp. 416-427
Author(s):  
V. Vlčková ◽  
M. Malinová ◽  
B. Koubková ◽  
J. Száková ◽  
V. Zídek ◽  
...  

The long-term accumulation of risk elements (As, Cd, Pb) originated from differently contaminated soils in rat organism was investigated during a model two-generation experiment. The effect of soil contamination level, gender, and length of exposure as well as the interactions between risk elements and selected essential macro- and microelements were studied. Rat diet contained 10% of individual soils (based on dry weight): (i) Fluvisol heavily polluted by As, Cd, Zn, and Pb, (ii) Luvisol contaminated by As, Cd, and Zn, and (iii) uncontaminated Chernozem. Male and female Wistar rats used for the experiment were housed in cages in a room with controlled temperature for 60 days and were fed ad libitum the mentioned diets. Subsequently, the pregnant females were continuously fed the experimental diet until weaning when the young animals were separated to male and female and fed the experimental diet till day 110 of age. The element contents in rat tissues reflected the risk element contents in contaminated soils. The bioaccessibility and bioavailability of the risk elements decreased in the order Cd&gt;As&gt;Pb and was affected by the soil physicochemical parameters. No significant differences were observed between male and female rats as well as between the first and the second generation. However, interactions were reported among the risk elements where the high cadmium content in Fluvisol resulted in increasing arsenic accumulation in the rat liver. Moreover, arsenic&ndash;copper interactions were observed where significant increase of the copper level was determined in kidney of the animals fed Luvisol exceeding 50-fold the maximum permissible limits for As content in agricultural soils. Among the hematological and biochemical characteristics of rats, total erythrocyte count (Er), hematocrit (Hct) increased confirming adverse effect of soil-derived risk elements especially in male rats. &nbsp;


2008 ◽  
Vol 27 (3_suppl) ◽  
pp. 101-118 ◽  
Author(s):  
Eri Watanabe ◽  
Terutaka Kodama ◽  
Takeshi Masuyama ◽  
Shoji Tsubuku ◽  
Akira Otabe ◽  
...  

Dihydrocapsiate, (4-hydroxy-3-methoxybenzyl 8-methylnonanoate; CAS No. 205687-03-2) is a naturally occurring capsinoid compound found in nonpungent chili peppers. Although the safety of synthetically produced dihydrocapsiate has been previously evaluated, the purpose of this 13-week gavage toxicity study is to evaluate dihydrocapsiate produced with a slightly modified manufacturing process. Sprague-Dawley rats, 10 rats/sex/group, 6 weeks of age at study initiation, were administered the dihydrocapsiate daily by gavage at dose levels of 0 (vehicle), 100,300, or 1000 mg/kg/day. The rats were observed for antimortem and postmortem signs of toxicity, including changes in clinical signs, body weights, food consumption, water intake, ophthalmology, clinical pathology (clinical chemistry, hematology, urinalysis), tissue findings (macroscopic and microscopic examination), as well as organ weights. There were no changes observed in clinical signs, body weight, food consumption, water intake, ophthalmology, urinalysis, hematology, or blood chemistry that were attributable to the administration of dihydrocapsiate. The only change observed attributable to the dihydrocapsiate administration involved the liver and that change occurred only at the high dose (1000 mg/kg). Both sexes had an increase in organ weights, but this increase correlated with a change in histopathology (i.e., hepatocyte hypertrophy) only in the males. No dihydrocapsiate-related histopathological changes were observed in males at doses ≤300 mg/kg or in females at any of the doses tested (≤1000 mg/kg). It was concluded that the no observed adverse effect level (NOAEL) of dihydrocapsiate was 300 mg/kg/day for male rats and 1000 mg/kg/day for female rats in this 13 week gavage study.


1985 ◽  
Vol 54 (3) ◽  
pp. 593-603 ◽  
Author(s):  
Eisa Omer Ahmed ◽  
Yudkin John

1. The claims that rats fed on diets with ‘brown sugar’ (unrefined muscovado) perform better in a number of ways than do rats fed on refined white sugar (sucrose) have been examined.2. Male Wistar rats were fed on purified diets from weaning, in which the carbohydrate component was either maize starch or unrefined sugar or sucrose. The sugars produced no differences in growth rate, body composition, or the weights of liver or kidneys. Compared with sucrose, unrefined sugar produced an increase in blood cholesterol and in the activity of hepatic fatty acid synthetase, and a greater increase in blood triglyceride. In confirmation of earlier results, rats fed on either sugar had heavier livers and kidneys, increased activity of hepatic glucose-6-phosphate dehydrogenase (EC 1.1.1.49) and a higher concentration of plasma triglyceride compared with rats fed on maize starch.3. Female Sprague-Dawley rats were fed on the same three diets as the male rats, and mated when they weighed about 200 g. No difference was seen in their ability to mate, the progress of pregnancies, or the sizes of the litters. Does fed on unrefined sugar produced litters of higher viability than did does fed on starch or sucrose. Survival was between 85 and 100% with unrefined sugar and between 30 and 75% with starch or sucrose.4. Unrefined muscovado sugar has thus been shown to contain a factor required by female rats for the proper viability of their pups. This may be the same ‘Reproductive Factor R’ as that described by Wiesner & Yudkin (1951). In certain circumstances, unrefined muscovado sugar might therefore contribute to the nutritional value of a human diet, although in what circumstances, in what respect and to what extent it might do so, is by no means clear.


1998 ◽  
Vol 76 (4) ◽  
pp. 381-386 ◽  
Author(s):  
Mahmoud M El-Mas ◽  
Abdel A Abdel-Rahman

In previous studies, we have shown that the baroreflex control of heart rate is significantly attenuated in females compared with age-matched males. This study investigated the role of estrogen in the modulation of baroreflex function in conscious unrestrained rats. Baroreflex-mediated decreases in heart rate in response to increments in blood pressure evoked by phenylephrine were evaluated in conscious freely moving male and female Sprague-Dawley rats as well as in ovariectomized rats. The effect of a 2-day 17 beta -estradiol (50 µg ·kg-1 ·day-1, s.c.) or vehicle treatment on baroreflex sensitivity was investigated in ovariectomized rats. Intravenous bolus doses of phenylephrine (1-16 µg/kg) elicited dose-dependent pressor and bradycardic responses in all groups of rats. Regression analysis of the baroreflex curves relating increments in blood pressure to the associated heart rate responses revealed a significantly (p < 0.05) smaller baroreflex sensitivity in female compared with male rats (-1.22 ± 0.07 and -1.85 ± 0.15 beats ·min-1 ·mmHg-1, respectively), suggesting an attenuated baroreflex function in females. In age-matched ovariectomized rats, baroreflex sensitivity showed further reduction (-0.93 ± 0.02 beats ·min-1 ·mmHg-1). Treatment of ovariectomized rats with 17 beta -estradiol significantly (p < 0.05) enhanced the baroreflex sensitivity (-1.41 ± 0.16 beats ·min-1 ·mmHg-1) to a level that was slightly higher than that of sham-operated female rats. Furthermore, baroreflex sensitivity of ovariectomized estradiol-treated rats was not significantly different from that of age-matched male rats. The vehicle, on the other hand, had no effect on baroreflex sensitivity of ovariectomized rats. These data support our earlier findings that sexual dimorphism exists in baroreflex control of heart rate. More importantly, the present study provides experimental evidence that suggests a facilitatory role for estrogen in the modulation of baroreflex function.Key words: rat, gender, baroreflex sensitivity, 17 beta -estradiol, ovariectomy.


Biologia ◽  
2013 ◽  
Vol 68 (4) ◽  
Author(s):  
Peter Orendáš ◽  
Ivan Ahlers ◽  
Bianka Bojková ◽  
Monika Kassayová ◽  
Peter Kubatka ◽  
...  

AbstractChemopreventive effect of non-steroidal antiinflammatory drugs (NSAIDs) in mammary carcinogenesis was reported in several studies. In this study, the effect of a nonselective cyclooxygenase inhibitor diclofenac (DICLO) in the prevention of N-methyl-N-nitrosourea (NMU)-induced mammary carcinogenesis in Sprague-Dawley female rats was evaluated. NMU was administered to animals intraperitoneally in two doses of 50 mg kg−1 b.w. within postnatal days 42-48. In experiment A (short-term administration), DICLO was administrated intramuscularly (5 mg kg−1 b.w.) every other day, starting 3 days before and for subsequent 25 days after first NMU injection. In experiment B (long-term administration), DICLO was administered in tap water (0.01 mg ml−1) continually, starting 7 days before and for subsequent 22 weeks after first NMU dose. The study was terminated 22 weeks after the first dose of NMU in both experiments. After DICLO treatment, tumor frequency per group was reduced in both variants of drug administration: in experiment A by 38% and in experiment B by 39.5%. Moreover, DICLO decreased tumor incidence by 11.5% and delayed tumor latency by 14 days in experiment B. In our preventive-curative experiments DICLO decreased some parameters of NMU-induced rat mammary carcinogenesis, mainly the tumor frequency.


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