Intermittent Fasting for Twelve Weeks Leads to Increases in Fat Mass and Hyperinsulinemia in Young Female Wistar Rats

Fasting is known to cause physiological changes in the endocrine pancreas, including decreased insulin secretion and increased reactive oxygen species (ROS) production. However, there is no consensus about the long-term effects of intermittent fasting (IF), which can involve up to 24 hours of fasting interspersed with normal feeding days. In the present study, we analyzed the effects of alternate-day IF for 12 weeks in a developing and healthy organism. Female 30-day-old Wistar rats were randomly divided into two groups: control, with free access to standard rodent chow; and IF, subjected to 24-hour fasts intercalated with 24-hours of free access to the same chow. Alternate-day IF decreased weight gain and food intake. Surprisingly, IF also elevated plasma insulin concentrations, both at baseline and after glucose administration collected during oGTT. After 12 weeks of dietary intervention, pancreatic islets displayed increased ROS production and apoptosis. Despite their lower body weight, IF animals had increased fat reserves and decreased muscle mass. Taken together, these findings suggest that alternate-day IF promote β -cell dysfunction, especially in developing animals. More long-term research is necessary to define the best IF protocol to reduce side effects.

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Short- and long-term effects on reproductive parameters of female Wistar rats after exposure to rosuvastatin starting in pre-puberty

Current Research in Toxicology ◽

10.1016/j.crtox.2020.11.002 ◽

2020 ◽

Vol 1 ◽

pp. 149-160

Author(s):

Jorge W.F. Barros ◽

Karolina S. Tonon ◽

Cibele S. Borges ◽

Patrícia V. Silva ◽

Ana F.Q. Lozano ◽

...

Keyword(s):

Wistar Rats ◽

Reproductive Parameters ◽

Long Term Effects ◽

Female Wistar Rats ◽

Short And Long Term

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Long-Term Effects of Neural Precursor Cell Transplantation on Secondary Injury Processes and Functional Recovery after Severe Cervical Contusion-Compression Spinal Cord Injury

International Journal of Molecular Sciences ◽

10.3390/ijms222313106 ◽

2021 ◽

Vol 22 (23) ◽

pp. 13106

Author(s):

Alexander Younsi ◽

Guoli Zheng ◽

Lennart Riemann ◽

Moritz Scherer ◽

Hao Zhang ◽

...

Keyword(s):

Spinal Cord ◽

Functional Recovery ◽

Wistar Rats ◽

Precursor Cell ◽

Secondary Injury ◽

Neural Precursor Cell ◽

Long Term Effects ◽

Cord Injury ◽

Female Wistar Rats

Cervical spinal cord injury (SCI) remains a devastating event without adequate treatment options despite decades of research. In this context, the usefulness of common preclinical SCI models has been criticized. We, therefore, aimed to use a clinically relevant animal model of severe cervical SCI to assess the long-term effects of neural precursor cell (NPC) transplantation on secondary injury processes and functional recovery. To this end, we performed a clip contusion-compression injury at the C6 level in 40 female Wistar rats and a sham surgery in 10 female Wistar rats. NPCs, isolated from the subventricular zone of green fluorescent protein (GFP) expressing transgenic rat embryos, were transplanted ten days after the injury. Functional recovery was assessed weekly, and FluoroGold (FG) retrograde fiber-labeling, as well as manganese-enhanced magnetic resonance imaging (MEMRI), were performed prior to the sacrifice of the animals eight weeks after SCI. After cryosectioning of the spinal cords, immunofluorescence staining was conducted. Results were compared between the treatment groups (NPC, Vehicle, Sham) and statistically analyzed (p < 0.05 was considered significant). Despite the severity of the injury, leading to substantial morbidity and mortality during the experiment, long-term survival of the engrafted NPCs with a predominant differentiation into oligodendrocytes could be observed after eight weeks. While myelination of the injured spinal cord was not significantly improved, NPC treated animals showed a significant increase of intact perilesional motor neurons and preserved spinal tracts compared to untreated Vehicle animals. These findings were associated with enhanced preservation of intact spinal cord tissue. However, reactive astrogliosis and inflammation where not significantly reduced by the NPC-treatment. While differences in the Basso–Beattie–Bresnahan (BBB) score and the Gridwalk test remained insignificant, animals in the NPC group performed significantly better in the more objective CatWalk XT gait analysis, suggesting some beneficial effects of the engrafted NPCs on the functional recovery after severe cervical SCI.

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Inhibition of post-partum maternal behaviour in the rat by injecting an oxytocin antagonist into the cerebral ventricles

Journal of Endocrinology ◽

10.1677/joe.0.1120275 ◽

1987 ◽

Vol 112 (2) ◽

pp. 275-282 ◽

Cited By ~ 168

Author(s):

E. van Leengoed ◽

E. Kerker ◽

H. H. Swanson

Keyword(s):

Wistar Rats ◽

Post Partum ◽

Rapid Onset ◽

Maternal Behaviour ◽

Cerebral Ventricles ◽

Long Term Effects ◽

Nesting Material ◽

The Right ◽

Oxytocin Antagonist

ABSTRACT Endogenous oxytocin released into the brain at parturition may stimulate the onset of maternal behaviour. In this study an attempt was made to block spontaneous maternal behaviour following natural delivery in Wistar rats by the injection of an antagonist of oxytocin into the cerebral ventricles. The analogue antagonist, d(CH2)5-8-ornithine-vasotocin, was administered by injection into a chronically implanted cannula in the right lateral ventricle at hourly intervals, beginning immediately after the expulsion of the first pup. The antagonist did not interfere with the normal progress of parturition or birth-related behaviours. After delivery of the last pup, mothers rested for 40 min in the test cage with the pups having been removed. Four pups and standard nesting material were then presented. Latency to pup carrying and duration of pup manipulation, nest building, and time spent on the nest with the pups, as well as duration of autogrooming and general activity were determined. Saline-injected controls started gathering the pups immediately and usually showed all elements of maternal behaviour within 10 min. Antagonist-treated mothers showed a marked delay in the onset of pup grouping and other maternal behaviours. At the end of 1 h, two out of six mothers had not yet picked up a single infant. Pups left overnight with their mothers were gathered into the nest and suckled, and no long-term effects of the antagonist were evident on retesting. The effectiveness of oxytocin antagonist in suppressing the rapid onset of post-partum maternal behaviour supports the hypothesis that centrally released oxytocin is involved in this process. It is noteworthy that these effects were obtained in Wistar rats, a strain in which oxytocin has failed to accelerate responsiveness to pups in virgin females. J. Endocr. (1987) 112, 275–282

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Long-term valproate treatment induces changes in ovarian morphology and serum sex steroid hormone levels in female Wistar rats

Seizure ◽

10.1053/seiz.1999.0342 ◽

1999 ◽

Vol 8 (8) ◽

pp. 490-493 ◽

Cited By ~ 35

Author(s):

Erik Taubøll ◽

Jouko I.T. Isojärvi ◽

Hanne Flinstad Harbo ◽

Arto J. Pakarinen ◽

Leif Gjerstad

Keyword(s):

Wistar Rats ◽

Steroid Hormone ◽

Sex Steroid ◽

Sex Steroid Hormone ◽

Hormone Levels ◽

Ovarian Morphology ◽

Female Wistar Rats

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Levels of glutathione-related antioxidants in some tissues of stressed Wistar rats

Indian Journal of Physiology and Pharmacology ◽

10.25259/ijpp_41_2020 ◽

2021 ◽

Vol 65 ◽

pp. 167-176

Author(s):

Bartholomew Chukwuebuka Nwogueze ◽

Anthony Emeka Ojieh ◽

Chukwuemeka Peter Aloamaka ◽

John Chukwuka Igweh ◽

Innocent Onyesom

Keyword(s):

Wistar Rats ◽

Antioxidant Activities ◽

Standard Procedure ◽

Living Organism ◽

Experimental Period ◽

Stressful Events ◽

Activity Level ◽

Free Access ◽

Female Wistar Rats ◽

The Impact

Objectives: Oxidative stress (OS)-related pathologic conditions in the tissues of living organism have been linked to exposure to stressful events within the environment. This study examined the impact of different kinds of stress exposure on glutathione (GSH)-related antioxidants. The effect of stress was examined using comparative levels of GSH, glutathione-S-transferase (GST) and glutathione peroxidase (GPx) in female Wistar rats. Materials and Methods: One hundred and sixty-eight adult female Wistar rats with body weights ranging between 150 and 200 g, were used for the study. The animals were distributed into 28 groups of six animals each. The experimental animals were routinely exposed to three different stressors; restraint chamber test, mirror chamber test and intruder chamber test for a duration of 1, 3 or 5 h per day for 1, 2 and 3 weeks, respectively. All animals were allowed free access to food (rat chaws), with water ad libitum. Animals were euthanise through cervical dislocation after the experimental period and the different target tissues were carefully harvested and homogenised for antioxidant estimation following standard procedure. Data obtained were statistically analysed and values expressed as mean ± standard error of mean and P < 0.05 level was considered as statistically significant. Results: Findings from this study elucidated the fact that exposure to stress is capable of causing marked OS and reducing GSH-based antioxidant activities in Wistar rats. A decline in the GSH level and GPx activity as observed in the study is an indication of alterations of kidney and brain tissue cellular integrity by free radicals generated during exposure to the stressors, while the observed significant increase in GST activity level in the affected tissues indicates compromised rapid exhaustion of the cellular system. Conclusion: Hence, we conclude that stress of different nature, intensity and duration can alter the levels of GSH-related antioxidants, especially in the kidney, ovary and brain tissues of stressed Wistar rats. The GSH levels in liver tissues were observed not to have changed significantly despite the oxidative damage caused by the stressors.

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Compartment analysis of metabolism of chromium(III) in rats of various ages.

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1977.232.5.e478 ◽

1977 ◽

Vol 232 (5) ◽

pp. E478 ◽

Cited By ~ 2

Author(s):

C Onkelinx

Keyword(s):

Intravenous Injection ◽

Wistar Rats ◽

Age Group ◽

Compartment Analysis ◽

Single Intravenous Injection ◽

Female Wistar Rats ◽

Disappearance Curve ◽

Plasma Disappearance Curve ◽

Mammillary Model

The metabolism of chromium(III) was studied in groups of female Wistar rats of various ages (35, 60, and 120 days) after a single intravenous injection of 51CrCl3 in trace amounts. In all the animals, the plasma disappearance curve could be adequately described by a sum of three exponential terms between 0 and 265 h postinjection. A three-compartment mammillary model is proposed that permits the description of Cr(III) metabolism in quantitative terms. The model defines compartment volumes, clearances by exchange, and clearances by excretion. The total excretory clearance is the sum of three components: urinary clearance (fu), fecal clearance (fd), and a residual clearance (fs), corresponding to an apparently irreversible deposition of chromium into long term body reservoirs. The parameters of the model are reported for each age group; when their values are expressed per 100 g of body wt, all the components of the excretory clearance decrease with age. In all cases elimination takes place primarily via the urine and fs accounts for 31-41% of the total excretory clearance. Consistent with the model, 51Cr was found to accumulate with time in several organs such as bone, kidney, spleen, and liver after a single intravenous injection of 51CrCl3.

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OESTROGEN AND THE CONTROL OF GONADOTROPHIN SECRETION IN THE IMMATURE RAT

Journal of Endocrinology ◽

10.1677/joe.0.0630285 ◽

1974 ◽

Vol 63 (2) ◽

pp. 285-298 ◽

Cited By ~ 7

Author(s):

F. DÖCKE ◽

G. DÖRNER

Keyword(s):

Wistar Rats ◽

Short Term ◽

Oestrogen Treatment ◽

Immature Rat ◽

Inhibiting Effect ◽

Gonadotrophin Secretion ◽

Oestradiol Benzoate ◽

Female Wistar Rats ◽

Implantation Method

SUMMARY Experiments were performed in female Wistar rats on the mode of action of oestrogen in affecting gonadotrophin secretion during infancy. Using an improved implantation method, former findings on a hypophysial site of oestrogen action in the Hohlweg effect were confirmed. The sensitivity to the ovulation-inducing effect of oestradiol benzoate (OB) increased as the rats approached the age of natural puberty. The first spontaneous ovulation could be suppressed by intrahypophysial, but not by intrahypothalamic, progesterone implants. A single s.c. injection or intracranial administration of OB at 25 or 26 days of age, although leading to premature vaginal opening (VO) and, in some of the animals, to one ovulation, did not induce true precocious puberty. To accelerate the onset of puberty, 0·05 μg OB/100 g body wt had to be injected daily from 5 days of age to VO, or from day 5 to day 10 and, additionally, from day 26 to VO. After long-term oestrogen treatment, the gonadotrophin-inhibiting effect of OB implanted into the middle hypothalamus from 26 to 34 days of age was significantly reduced in comparison with untreated control rats. A final experiment demonstrated that the first ovarian cycle was not prolonged after neonatal ovariectomy and implantation of ovaries at 24, 28 or 32 days of age. The results indicate that similar neurohormonal mechanisms are operational at the first pubertal and at later cyclic ovulations. They also indicate that the maturation of the gonadotrophin-controlling mechanisms continues during infancy in the absence of ovarian steroids. It can be accelerated in Wistar rats by long-term, but not by short-term prepubertal oestrogen treatment.

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