scholarly journals Functional and Muscle Size Response to 5 Days of Treadmill Training in Young Rats

1997 ◽  
Vol 9 (4) ◽  
pp. 324-330 ◽  
Author(s):  
Alon Eliakim ◽  
Mark Y. Moromisato ◽  
David Y. Moromisato ◽  
Dan M. Cooper
Keyword(s):  
Young Female ◽  
Treadmill Training ◽  
Female Rats ◽  
Muscle Size ◽  
Female Rat ◽  
Sprague Dawley ◽  
Running Time ◽  
Sprague Dawley Rats ◽  
Hindlimb Muscle ◽  
Training Response

In this study, the hypothesis that improvements in functional and structural measures could be detected in the young, female rat with only 5 days of moderate treadmill training was tested. Eight-week-old female Sprague-Dawley rats were divided randomly into control (n = 10) and training groups (n = 11). Over the 5-day period, running duration and treadmill speed increased progressively. Maximal running time and gas exchange were measured on Day 6. In trained compared with control rats, maximal running time was 54% greater (p < .005), right hindlimb muscle was 16% heavier (p < .01), and end-exercise respiratory exchange ratio (RER) was 17% lower (p < .05). Substantial metabolic and structural adaptations occurred in young female rats after only 5 days of treadmill training. This protocol may be useful in discovering the initiating mechanisms of the training response in the young organism.

Infarct size is increased in female post-MI rats treated with rapamycin

2009 ◽  
Vol 87 (6) ◽  
pp. 460-470 ◽  
Author(s):  
Claude Lajoie ◽  
Viviane El-Helou ◽  
Cindy Proulx ◽  
Robert Clément ◽  
Hugues Gosselin ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Female Rats ◽  
Coronary Artery Ligation ◽  
Female Rat ◽  
Sprague Dawley ◽  
Ischemic Insult ◽  
Fibrotic Response ◽  
Artery Ligation ◽  
Sprague Dawley Rats ◽  
Scar Healing

Rapamycin represents a recognized drug-based therapeutic approach to treat cardiovascular disease. However, at least in the female heart, rapamycin may suppress the recruitment of putative signalling events conferring cardioprotection. The present study tested the hypothesis that rapamycin-sensitive signalling events contributed to the cardioprotective phenotype of the female rat heart after an ischemic insult. Rapamycin (1.5 mg/kg) was administered to adult female Sprague–Dawley rats 24 h after complete coronary artery ligation and continued for 6 days. Rapamycin abrogated p70S6K phosphorylation in the left ventricle of sham rats and the noninfarcted left ventricle (NILV) of 1-week postmyocardial-infarcted (MI) rats. Scar weight (MI 0.028 ± 0.006, MI+rapamycin 0.064 ± 0.004 g) and surface area (MI 0.37 ± 0.08, MI+rapamycin 0.74 ± 0.03 cm2) were significantly larger in rapamycin-treated post-MI rats. In the NILV of post-MI female rats, rapamycin inhibited the upregulation of eNOS. Furthermore, the increased expression of collagen and TGF-β3 mRNAs in the NILV were attenuated in rapamycin-treated post-MI rats, whereas scar healing was unaffected. The present study has demonstrated that rapamycin-sensitive signalling events were implicated in scar formation and reactive fibrosis. Rapamycin-mediated suppression of eNOS and TGF-β3 mRNA in post-MI female rats may have directly contributed to the larger infarct and attenuation of the reactive fibrotic response, respectively.

scholarly journals Greater natriuretic response to ENaC inhibition in male versus female Sprague-Dawley rats

2020 ◽  
Vol 318 (2) ◽  
pp. R418-R427 ◽  
Author(s):  
Reham H. Soliman ◽  
Jermaine G. Johnston ◽  
Eman Y. Gohar ◽  
Crystal M. Taylor ◽  
David M. Pollock
Keyword(s):  
Protein Expression ◽  
Time Of Day ◽  
Female Rats ◽  
Female Rat ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Endothelin System ◽  
Males And Females ◽  
Epithelial Sodium Channel Enac

Genes for the epithelial sodium channel (ENaC) subunits are expressed in a circadian manner, but whether this results in time-of-day differences in activity is not known. Recent data show that protein expression of ENaC subunits is higher in kidneys from female rats, yet females are more efficient in excreting an acute salt load. Thus, our in vivo study determined whether there is a time-of-day difference as well as a sex difference in the response to ENaC inhibition by benzamil. Our results showed that the natriuretic and diuretic responses to a single dose of benzamil were significantly greater in male compared with female rats whether given at the beginning of the inactive period [Zeitgeber time 0 (ZT0), 7 AM] or active period (ZT12, 7 PM). However, the response to benzamil was not significantly different between ZT0 and ZT12 dosing in either male or female rats. There was no difference in renal cortical α-ENaC protein abundance between ZT0 and ZT12 or males and females. Given previous reports of flow-induced stimulation of endothelin-1 (ET-1) production and sex differences in the renal endothelin system, we measured urinary ET-1 excretion to assess the effects of increased urine flow on intrarenal ET-1. ET-1 excretion was significantly increased following benzamil administration in both sexes, but this increase was significantly greater in females. These results support the hypothesis that ENaC activity is less prominent in maintaining Na+ balance in females independent of renal ET-1. Because ENaC subunit genes and protein expression vary by time of day and are greater in female rat kidneys, this suggests a clear disconnect between ENaC expression and channel activity.

The incidence of chronic progressive nephrosis in young Sprague-Dawley rats from two different breeders

1998 ◽  
Vol 32 (4) ◽  
pp. 477-482 ◽  
Author(s):  
Maud Palm
Keyword(s):  
Kidney Function ◽  
Young Female ◽  
Female Rats ◽  
Common Finding ◽  
Sprague Dawley ◽  
Laboratory Rats ◽  
Toxicity Studies ◽  
Sprague Dawley Rats ◽  
Males And Females

Chronic progressive nephrosis (CPN) in rats may not only become a problem in long-term toxicity studies but also in short-term studies, if the breeding stock is not carefully selected with respect to the kidney function. This paper presents differences in kidney function between young rats of the same strain, Sprague-Dawley, but from two different breeders ('set A' and 'set B' rats). In set A rats, protein in the urine was present in the males, which is a common finding. In set B rats, not only the males but also the females excreted protein in the urine. The method used to detect protein in the urine does not normally show a positive protein result in the young female rats. At the age of 3 months signs of chronic progressive nephrosis were observed in 55% of the males and in 15% of the females in set B. Two months later, the incidence had increased to about 70–80% in males and 50% in females. At 8 months, the incidence was similar, but the severity had increased. These values were compared with those obtained from the set A rats, none of which showed any signs of the disease at the age of 5 months and only 5% of the males and females at the age of 8 months. The results indicated that an increased excretion of protein in the urine may be used as an indicator for chronic progressive nephrosis in the rat and that not only the strain but also the source is important in selecting laboratory rats for toxicity studies.

scholarly journals Dietary n-6 and n-3 PUFA alter the free oxylipin profile differently in male and female rat hearts

2019 ◽  
Vol 122 (03) ◽  
pp. 252-261 ◽  
Author(s):  
Afroza Ferdouse ◽  
Shan Leng ◽  
Tanja Winter ◽  
Harold M. Aukema
Keyword(s):  
Dietary Treatment ◽  
Interactive Effects ◽  
Female Rats ◽  
Female Rat ◽  
Sprague Dawley ◽  
Oil Composition ◽  
American Institute ◽  
Sprague Dawley Rats ◽  
Rat Hearts ◽  
Health And Disease

AbstractOxylipins are bioactive lipid mediators synthesised from PUFA. The most well-known oxylipins are the eicosanoids derived from arachidonic acid (ARA), and many of them influence cardiac physiology in health and disease. Oxylipins are also formed from other n-3 and n-6 PUFA such as α-linolenic acid (ALA), EPA, DHA and linoleic acid (LA), but fundamental data on the heart oxylipin profile, and the effect of diet and sex on this profile, are lacking. Therefore, weanling female and male Sprague–Dawley rats were given American Institute of Nutrition (AIN)-93G-based diets modified in oil composition to provide higher levels of ALA, EPA, DHA, LA and LA + ALA, compared with control diets. After 6 weeks, free oxylipins in rat hearts were increased primarily by their precursor PUFA, except for EPA oxylipins, which were increased not only by dietary EPA but also by dietary ALA or DHA. Dietary DHA had a greater effect than ALA or EPA on reducing ARA oxylipins. An exception to the dietary n-3 PUFA-lowering effects on ARA oxylipins was observed for several ARA-derived PG metabolites that were higher in rats given EPA diets. Higher dietary LA increased LA oxylipins, but it had no effect on ARA oxylipins. Overall, heart oxylipins were higher in female rats, but this depended on dietary treatment: the female oxylipin:male oxylipin ratio was higher in rats provided the ALA compared with the DHA diet, with other diet groups having ratios in between. In conclusion, individual PUFA and sex have unique and interactive effects on the rat heart free oxylipin profile.

Short-term Effect of Monosodium glutamate on serum hormonal level and histological changes of uterus during estrus phase in rat

2021 ◽  
Author(s):  
Mahfoudh Almuslai Mohammed Abdulghani
Keyword(s):  
Monosodium Glutamate ◽  
Young Female ◽  
Female Rats ◽  
Control Group ◽  
Treated Animal ◽  
Sprague Dawley ◽  
Serum Progesterone ◽  
Animal Group ◽  
Sprague Dawley Rats ◽  
Institutional Services

Abstract Background Monosodium glutamate (MSG) is commonly used in the Middle East and worldwide as a flavour enhancer in food. MSG is called Chinese salt and is commonly used by the food processing industry, restaurants, and institutional services. The current study was conducted to investigate the effects of monosodium glutamate on the uterine tissue of adult female Sprague Dawley rats with a regular estrus cycle. Results The mean relative values of progesterone and estrogen to the control in the MSG-treated animal group significantly affect (P < 0.05) compared with the control group. The means of the relative lumen area (um2) showed smaller than the control group. Conclusions MSG may cause disturbance in serum progesterone and estrogen levels in young female rats. So, a precautionary utilised for this compound, especially for females under risk factor of hormonal abnormality, is recommended. Further study should be conducted to evaluate the effect of MSG on corpus lutea function.

EVIDENCE FOR PLEIOMORPHISM OF LUTEINIZING HORMONE IN PERIPUBERTAL FEMALE RATS

1978 ◽  
Vol 79 (1) ◽  
pp. 133-134 ◽  
Author(s):  
M. B. TER HAAR ◽  
CATHERINE A. WILSON
Keyword(s):  
Luteinizing Hormone ◽  
Female Rats ◽  
Female Rat ◽  
Hormonal Changes ◽  
Sprague Dawley ◽  
Present Communication ◽  
Royal Veterinary College ◽  
Animal Physiology ◽  
Sprague Dawley Rats ◽  
Pregnant Mare Serum Gonadotrophin

*A.R.C. Institute of Animal Physiology, Babraham, Cambridge, CB2 4AT, and ‡Department of Physiology, Royal Veterinary College, London, NW1 OTU (Received 28 March 1978) Ovulation can be induced precociously in the prepubertal female rat by the administration of pregnant mare serum gonadotrophin (PMSG), provided that the animal weighs over 60 g (Wilson, Endersby & McDonald, 1974). The hormonal changes brought about by this treatment have been studied (J. C. Buckingham, M. B. ter Haar, A. S. McNeilly & C. A. Wilson, data to be published) and it has been found that the preovulatory concentrations of radioimmunoassayable luteinizing hormone (LH) varied according to the antiserum used. These findings are described in the present communication. Female Sprague–Dawley rats (Tuck & Sons, Rayleigh, Essex) were brought into the department on day 21 of life, kept under conditions of controlled lighting (lights on 05.00–19.00 h) and provided with pelleted rat diet (No. 86, Dixon &

scholarly journals Effects of Large Doses of Androgen on Rodent Erythropoiesis and Body Composition

Blood ◽  
1965 ◽  
Vol 26 (4) ◽  
pp. 411-420 ◽  
Author(s):  
DAVID G. NATHAN ◽  
FRANK H. GARDNER ◽  
Alvera L. Kan
Keyword(s):  
Body Composition ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Red Cell ◽  
Sprague Dawley ◽  
Renal Hypertrophy ◽  
Lean Tissue ◽  
Sprague Dawley Rats ◽  
Erythropoietic Response

Abstract Six weeks treatment of male and female mature Sprague-Dawley rats with 8 mg. testosterone enanthate per week produced varied effects depending upon the sex of the animal. Compared to controls, the androgen-treated female rats exhibited a greater gain in body weight which was predominantly water. There was concomitant renal hypertrophy and fat loss. An accelerated rate of erythropoiesis produced a gain in total red cell volume out of proportion to the accretion of lean tissue. Treated male rats gained somewhat less water and lean tissue and much less fat than controls. Definite evidence of acceleration of erythropoiesis was not observed. It is concluded that the female rat is more sensitive to the erythropoietic effects of large doses of androgen than is the male. The erythropoietic response to androgen in the female rat appears to be independent of the effects of the hormone on body composition.

scholarly journals Effects of ovariectomy and estrogen on ischemia-reperfusion injury in hindlimbs of female rats

2001 ◽  
Vol 91 (4) ◽  
pp. 1828-1835 ◽  
Author(s):  
Nicole Stupka ◽  
Peter M. Tiidus
Keyword(s):  
Muscle Damage ◽  
Ischemia Reperfusion Injury ◽  
Serum Insulin ◽  
Ischemia Reperfusion ◽  
Neutrophil Infiltration ◽  
Female Rats ◽  
Protective Effects ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
17Β Estradiol

The effects of estrogen and ovariectomy on indexes of muscle damage after 2 h of complete hindlimb ischemia and 2 h of reperfusion were investigated in female Sprague-Dawley rats. The rats were assigned to one of three experimental groups: ovariectomized with a 17β-estradiol pellet implant (OE), ovariectomized with a placebo pellet implant (OP), or control with intact ovaries (R). It was hypothesized that following ischemia-reperfusion (I/R), muscle damage indexes [serum creatine kinase (CK) activity, calpain-like activity, inflammatory cell infiltration, and markers of lipid peroxidation (thiobarbituric-reactive substances)] would be lower in the OE and R rats compared with the OP rats due to the protective effects of estrogen. Serum CK activity following I/R was greater ( P < 0.01) in the R rats vs. OP rats and similar in the OP and OE rats. Calpain-like activity was greatest in the R rats ( P < 0.01) and similar in the OP and OE rats. Neutrophil infiltration was assessed using the myeloperoxidase (MPO) assay and immunohistochemical staining for CD43-positive (CD43+) cells. MPO activity was lower ( P < 0.05) in the OE rats compared with any other group and similar in the OP and R rats. The number of CD43+ cells was greater ( P < 0.01) in the OP rats compared with the OE and R rats and similar in the OE and R rats. The OE rats had lower ( P < 0.05) thiobarbituric-reactive substance content following I/R compared with the R and OP rats. Indexes of muscle damage were consistently attenuated in the OE rats but not in the R rats. A 10-fold difference in serum estrogen content may mediate this. Surprisingly, serum CK activity and muscle calpain-like activity were lower ( P< 0.05) in the OP rats compared with the R rats. Increases in serum insulin-like growth factor-1 content ( P < 0.05) due to ovariectomy were hypothesized to account for this finding. Thus both ovariectomy and estrogen supplementation have differential effects on indexes of I/R muscle damage.

Cardiac response to doxorubicin and dexrazoxane in intact and ovariectomized young female rats at rest and after swim training

2012 ◽  
Vol 302 (10) ◽  
pp. H2048-H2057 ◽  
Author(s):  
Annie Calvé ◽  
Rami Haddad ◽  
Sarah-Neiel Barama ◽  
Melissa Meilleur ◽  
Igal A. Sebag ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Adult Survivors ◽  
Young Female ◽  
Cardiac Response ◽  
Female Rats ◽  
Cancer Therapies ◽  
Sprague Dawley ◽  
Cardiac Damage ◽  
Ovx Rats ◽  
The Impact

The impact of cancer therapies on adult cardiac function is becoming a concern as more children survive their initial cancer. Cardiovascular disease is now a significant problem to adult survivors of childhood cancer. Specifically, doxorubicin (DOX) may be particularly harmful in young girls. The objective of this study was to characterize DOX damage and determine the ability of dexrazoxane (DEX) to reduce DOX-mediated cardiac damage in sedentary and swim-trained female rats. Female Sprague-Dawley rats were left intact or ovariectomized (OVX) at weaning then injected with DEX (60 mg/kg) before DOX (3 mg/kg), DOX alone, or PBS. Rats were separated into sedentary and swim cohorts. Body weight was reduced in DOX:DEX- but not PBS- or DOX-treated rats. Echocardiographic parameters were similar in sedentary rats. Swim training revealed greater concentric remodeling in DOX-treated rats and reduced fractional shortening in DOX:DEX-treated rats. Calsequestrin 2 was reduced with DOX and increased with DOX:DEX postswim. Sarco(endo)plasmic reticulum Ca2+-ATPase 2a was reduced and calsequestrin 2 reduced further by swim training only in intact rats. OVX rats were heavier and developed eccentric remodeling post-swim with DOX and eccentric hypertrophy with DOX:DEX. Changes in SERCA2a and calsequestrin 2 expression were not observed. Ovariectomized DOX- and DOX:DEX-treated rats stopped growing during swim training. DEX coinjection did not relieve DOX-mediated cardiotoxicity in intact or hormone-deficient rats. DOX-mediated reductions in growth, cardiac function, and expression of calcium homeostasis proteins were exacerbated by swim. DEX coadministration did not substantially relieve DOX-mediated cardiotoxicity in young female rats. Ovarian hormones reduce DOX-induced cardiotoxicity.

scholarly journals Hypertensive female Sprague-Dawley rats require an intact nitric oxide synthase system for compensatory increases in renal regulatory T cells

2020 ◽  
Vol 319 (2) ◽  
pp. F192-F201
Author(s):  
Lindsey A. Ramirez ◽  
Ellen E. Gillis ◽  
Jacqueline B. Musall ◽  
Riyaz Mohamed ◽  
Elizabeth Snyder ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
T Cells ◽  
Angiotensin Ii ◽  
Nitric Oxide Synthase ◽  
Regulatory T Cells ◽  
Female Rats ◽  
Sprague Dawley ◽  
Albumin Excretion ◽  
Sprague Dawley Rats ◽  
Oxide Synthase

We have previously shown that hypertensive female rats have more regulatory T cells (Tregs), which contribute more to blood pressure (BP) control in female versus male rats. Based on known protective properties of Tregs, the goal of the present study was to investigate the mechanisms by which female rats maintain Tregs. The present study was designed to 1) compare the impact of three hypertension models on the percentage of renal Tregs and 2) test the hypothesis that nitric oxide synthase (NOS) inhibition prevents increases in renal Tregs and exacerbates renal damage in female Sprague-Dawley rats. Rats (11–14 wk old) were randomized to one of the following four groups: control, norepinephrine (NE) infusion, angiotensin II infusion, or the NOS inhibitor Nω-nitro-l-arginine methyl ester (l-NAME) in drinking water. BP was measured via tail cuff. After 2 wk of treatment, kidneys were isolated and processed to measure Tregs via flow cytometric analysis and renal injury via urinary albumin excretion, plasma creatinine, and histological analyses. Hypertensive treatments increased BP in all experimental animals. Increases in BP in norepinephrine-and angiotensin II-treated rats were associated with increases in renal Tregs versus control. In contrast, l-NAME treatment decreased Tregs compared with all groups. l-NAME treatment modestly increased albumin excretion. However, plasma creatinine was comparable among the groups, and there was no histological evidence of glomerular or tubular injury. This study provides insights into the mechanisms regulating renal Tregs and supports that an intact NOS system is crucial for female rats to have BP-related increases in renal Tregs.

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