scholarly journals Computer Pattern Recognition: Spontaneous Motor Activity Studies of Rats Following Acute Exposure to Triethyltin

1991 ◽  
Vol 10 (6) ◽  
pp. 705-718 ◽  
Author(s):  
W. J. Kernan ◽  
D. L. Hopper ◽  
M. P. Bowes
Keyword(s):  
Pattern Recognition ◽  
Red Light ◽  
Recognition System ◽  
Exposed Group ◽  
Light Cycle ◽  
Light Conditions ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Sprague Dawley Rats ◽  
Normal Light

A computer pattern recognition system, RAPID, was used to measure the spontaneous activity of male Sprague-Dawley rats during six observational periods distributed over 11 days after a single oral dose of triethyltin bromide (TET) at 3 or 5 mg/kg. These observational periods were distributed between those taken under red light conditions during the animals normal dark cycle (Days 2, 7, and 10 after exposure) and those taken under white light conditions during the animals normal light cycle (Days 3, 6, and 11 after exposure). Significant disruption of the normal behavioral patterns were observed on Days 2 and 7 for the 3 mg/kg-exposed group and on Days 2, 3, 6, 7, and 10 for the 5 mg/kg-exposed group.

Ovarian changes in Sprague-Dawley rats produced by nocturnal exposure to low intensity light

1995 ◽  
Vol 29 (3) ◽  
pp. 335-338 ◽  
Author(s):  
Eric Beys ◽  
Gerhard J. Nohynek ◽  
Keyword(s):  
Control Group ◽  
Corpora Lutea ◽  
Light Cycle ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Control Female ◽  
Low Intensity ◽  
Toxicology Study ◽  
Sprague Dawley Rats ◽  
Minimal Intensity

This study was performed to investigate the potential effects of nocturnal, low-intensity light upon ovarian morphology of female Sprague-Dawley rats and to investigate the cause for ovarian changes which had been observed in an earlier study following transient exposure of control female Sprague-Dawley rats to indirect light of minimal intensity during the nocturnal 12-h dark cycle. Twenty female Sprague-Dawley CD rats (initial age: 5 weeks) were kept for 8 weeks under our standard laboratory conditions including a daily 12-h light cycle (light intensity: approximately 200 lux) followed by a 12-h dark cycle with exposure to an indirect light source of low intensity (approximately 30 lux). Ten female control rats of comparable age from a concurrent toxicology study housed in an adjacent animal room under our standard 12 h light/dark cycle served as controls. At the end of the study the rats were sacrificed, necropsied and the ovaries were evaluated histopathologically. In 5 of the 20 animals we found ovarian atrophy consisting of decreased number and size of corpora lutea and increased number of tertiary follicles and/or follicular cysts. Most corpora lutea present in these ovaries were old, indicating the absence of recent ovulations. In contrast, the incidence of ovarian changes in the control group was 0/10. In conclusion, nocturnal exposure of female Sprague-Dawley rats to light of minimal intensity produced a substantial incidence of ovarian changes and suggests that the incidence of ovarian atrophy observed in a previous study may have been due to transient exposure to indirect nocturnal light of minimal intensity.

Both orexin receptors are expressed in rat ovaries and fluctuate with the estrous cycle: effects of orexin receptor antagonists on gonadotropins and ovulation

2007 ◽  
Vol 293 (4) ◽  
pp. E977-E985 ◽  
Author(s):  
Patricia Silveyra ◽  
Victoria Lux-Lantos ◽  
Carlos Libertun
Keyword(s):  
Structural Changes ◽  
Corpora Lutea ◽  
Light Cycle ◽  
Sprague Dawley ◽  
Receptor Antagonists ◽  
Dark Light ◽  
Orexin Receptors ◽  
Sprague Dawley Rats ◽  
The Central Nervous System ◽  
First Time

Orexins are peptides controlling feeding, sleep, and neuroendocrine functions. They are synthesized by the hypothalamus with projections throughout the brain. Orexins and their orexin 1 (OX1) and orexin 2 receptors (OX2) are present outside the central nervous system. Here the expression of preproorexin (PPO), OX1, and OX2 was studied in rat ovaries. PPO, OX1, and OX2 were determined by quantitative real-time RT-PCR in ovaries of cycling Sprague-Dawley rats on all days of the cycle. Serum hormones and food consumption were determined. Ovarian OX1 and OX2 expression was then studied after ovulation blockade with Cetrorelix or Nembutal. Finally, proestrous rats were treated at 1400 and 1900 with a selective OX1 antagonist (SB-334867-A) and/or a selective OX2 antagonist (JNJ-10397049), and hormone levels, ovulation, and ovarian histology were studied. Both receptors' expression increased in the ovary between 1700 and 2300 of proestrus exclusively, in coincidence with hormone peaks, but not with the dark-light cycle or food intake. PPO was not detected. Cetrorelix or Nembutal prevented the increases of OX1 and OX2 while blunting gonadotropin peaks. SB-334867-A and JNJ-10397049, alone or combined, decreased serum gonadotropins and reduced ova number the following morning; ovaries showed a bloody (hyperemic and/or hemorrhagic) reaction with more preovulatory follicles and less corpora lutea. Here we demonstrate for the first time an increased ovarian expression of both OX1 and OX2, only during proestrous afternoon, and its hormone dependence but not dependence on the dark-light cycle. Two new receptor antagonists reduced proestrous gonadotropins and/or ova number while producing ovarian structural changes.

scholarly journals The Effect on Rat Thymocytes of the Simultaneous In Vivo Exposure to 50-Hz Electric and Magnetic Field and to Continuous Light

2004 ◽  
Vol 4 ◽  
pp. 91-99 ◽  
Author(s):  
Daniela Quaglino ◽  
Miriam Capri ◽  
Luigi Zecca ◽  
Claudio Franceschi ◽  
Ivonne P. Ronchetti
Keyword(s):  
Light Exposure ◽  
Low Frequency ◽  
Continuous Light ◽  
Light Cycle ◽  
Sprague Dawley ◽  
Dark Light ◽  
Sprague Dawley Rats ◽  
Electric And Magnetic Fields

Thymus plays an important role in the immune system and can be modulated by numerous environmental factors, including electromagnetic fields (EMF). The present study has been undertaken with the aim to investigate the role of long-term exposure to extremely low frequency electric and magnetic fields (ELF-EMF) on thymocytes of rats housed in a regular dark/light cycle or under continuous light. Male Sprague-Dawley rats, 2 months old, were exposed or sham exposed for 8 months to 50-Hz sinusoidal EMF at two levels of field strength (1 kV/m, 5 μT and 5 kV/m, 100 μT, respectively). Thymus from adult animals exhibits signs of gradual atrophy mainly due to collagen deposition and fat substitution. This physiological involution may be accelerated by continuous light exposure that induces a massive death of thymocytes. The concurrent exposure to continuous light and to ELF-EMF did not change significantly the rate of mitoses compared to sham-exposed rats, whereas the amount of cell death was significantly increased, also in comparison with animals exposed to EMF in a 12-h dark-light cycle. In conclusion, long-term exposure to ELF-EMF, in animals housed under continuous light, may reinforce the alterations due to a photic stress, suggesting that,in vivo, stress and ELF-EMF exposure can act in synergy determining a more rapid involution of the thymus and might be responsible for an increased susceptibility to the potentially hazardous effects of ELF-EMF.

scholarly journals Female Sprague Dawley Rats Show Impaired Spatial Memory in the 8-Arm Radial Maze under Dim Blue and Red Light

2010 ◽  
Vol 2010 ◽  
pp. 1-8 ◽  
Author(s):  
Michael Pirchl ◽  
Georg Kemmler ◽  
Christian Humpel
Keyword(s):  
Spatial Memory ◽  
Radial Maze ◽  
Red Light ◽  
Training Session ◽  
Female Rats ◽  
Sprague Dawley ◽  
Male And Female ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Mood And Cognition

Light intensity and wavelength strongly influence mood and cognition in humans and rodent animal models. The aim of the present study was to explore if dim white (7.6–17.7 lux) , blue (1.3–2.3 lux), and red light (0.8–1.4 lux) affect spatial memory of male and female Sprague Dawley rats in the 8-arm radial maze. Our data show that spatial memory significantly improved within 5 daily learning sessions (each 5 trials) under dim white light, which was not different between male and female rats. However, dim blue and red light significantly reduced spatial learning of female rats in the 8-arm radial maze in the last training session (session 5). In conclusion, we suggest that female Sprague Dawley rats show reduced learning under blue and red light.

Abstract T P81: Long-Term Activity Levels Vary by Rat Strain Following Stroke: A Disruption of the Circadian Rhythm?

Stroke ◽  
2014 ◽  
Vol 45 (suppl_1) ◽  
Author(s):  
Allison Kunze ◽  
Dannielle Zierath ◽  
Olga Drogomiretskiy ◽  
Brett Jaspers ◽  
Tessa Barclay ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Infarct Volume ◽  
Therapeutic Interventions ◽  
Stroke Severity ◽  
Light Cycle ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Lewis Rats ◽  
Sd Rats

Background: Assessment of long-term behavioral outcome after experimental cerebral ischemia is important for evaluating potential therapeutic interventions. In this study, we explored strain related differences in baseline behavior and in response to stroke. Methods: Spontaneous cage activity was monitored (cm moved per hr) and analyzed before and after 2 hour middle cerebral artery occlusion (MCAO) in male Lewis, Wistar, and Sprague Dawley (SD) rats using the Noldus PhenoTyper® cages and EthoVision® Software system. Stroke severity was assessed using the neuroscore, foot fault errors, and performance on the rotarod. Infarct volume at 24 hours was determined in a second cohort of animals. Animals were sacrificed 56 days after MCAO. Data are analyzed using non-parametric statistics. Results: Prior to stroke, the median distance moved per hour during the dark was similar among the 3 strains, but Lewis rats were more active during the light cycle (P=0.001). Neuroscores did not differ between strains at 3 hrs after MCAO nor did infarct volumes at 24 hours after MCAO. Lewis rats, however, performed worse on the rotarod in the month following MCAO (P<0.05 at each time point). Foot fault errors were similar throughout the study period. After stroke, Lewis rats became more active during the dark cycle while Wistar and SD rats became more active during the light cycle (Figure). Summary: The 3 strains of rats evaluated in this study had different patterns in the change in activity after MCAO. Lewis rats showed an increase in activity during the dark cycle while Wistar and SD rats showed an increase in activity during the light cycle. This observation suggests that there are genetic differences in the response to stroke that may alter the circadian rhythm after stroke.

Abstract 1: Male Sprague Dawley Rats Exposed To Perinatal Hypoxia Are More Susceptible To Angiotensin II-induced Hypertension In Adulthood Vs Females

Hypertension ◽  
2020 ◽  
Vol 76 (Suppl_1) ◽  
Author(s):  
Lindsey A Ramirez ◽  
Terri Marin ◽  
Elizabeth Snyder ◽  
Michael W Brands ◽  
Jennifer C Sullivan
Keyword(s):  
Preterm Infants ◽  
Later Life ◽  
Pressure Effects ◽  
Light Cycle ◽  
Perinatal Hypoxia ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Induced Hypertension ◽  
Blood Pressure Effects

Preterm infants (born prior to 37 weeks (wks) gestation) are susceptible to hypoxia, which predisposes to hypertension in later life. Underdeveloped organs, including the kidney, prevent preterm infants from effectively regulating blood volume and O 2 delivery. Since rat nephrogenesis completes ~ postnatal day (PND) 8, we hypothesized that exposure to hypoxia before nephrogenesis is complete will promote hypertension in adulthood. Male and female Sprague Dawley pups were randomized to Ctrl (room air) or intermittent hypoxia (IH) at PND 1 (n=6/group). IH pups were exposed to ~10% O 2 three times a day, 10 minutes/session, from PND 1-8. O 2 saturation was measured at PND 6. Mean arterial pressure (MAP) was measured via telemetry from ~14 – 16 wks of age. To determine the MAP response to a cardiovascular challenge, osmotic minipumps containing angiotensin (Ang) II (400 ng/kg/min) were implanted at 15 wks of age. IH pups had lower O 2 saturation vs ctrl (P O2 <0.05). Light cycle (LC) and dark cycle (DC) MAP were similar in all groups at baseline. Following treatment, LC-MAP was higher in IH-M vs Ctrl-M, but similar among female groups (P Int . = 0.04). IH animals had higher DC-MAP vs ctrl (P O2 = 0.02). IH decreased blood oxygen, suggesting a global decrease in oxygen delivery to organs, similar to what is seen with hypoxia. Perinatal IH alone did not increase MAP. However, this exposure did increase MAP in response to Ang II. While both males and females exposed to perinatal hypoxia had higher Ang II-induced hypertension vs ctrls in the dark cycle, this effect was preserved only in males in the light cycle. This suggests males are more susceptible to blood pressure effects of perinatal IH.

scholarly journals Time-restricted feeding schedules modify temporal variation of gentamicin experimental nephrotoxicity.

1997 ◽  
Vol 41 (7) ◽  
pp. 1468-1474 ◽  
Author(s):  
D Beauchamp ◽  
C Guimont ◽  
L Grenier ◽  
M LeBrun ◽  
D Tardif ◽  
...  
Keyword(s):  
Renal Cortex ◽  
Renal Toxicity ◽  
Restricted Feeding ◽  
Feeding Period ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Fasting Period ◽  
Sprague Dawley Rats ◽  
Cellular Regeneration ◽  
Time Of Feeding

The effect of timing of gentamicin dosing relative to food access periods was evaluated in experimental animals. Female Sprague-Dawley rats were treated for 4 and 10 days with gentamicin (40 mg/kg of body weight/day) intraperitoneally at either 0700, 1300, 1900, or 0100 h according to three food presentation schedules: food was available from 0800 to 1600 h in the first group, from 1600 to 0000 h in the second group, and from 0000 to 0800 h in the last group. Animals were thus subjected to a restricted feeding period. Results indicate that time-restricted feeding schedules displace the peak and the trough of gentamicin-induced renal toxicity, as evaluated by changes in the inhibition of sphingomyelinase activity, cellular regeneration (incorporation of [3H]thymidine into DNA of renal cortex), and blood urea nitrogen and serum creatinine levels, as well as histopathological lesions observed after 10 days of treatment. In fact, the toxicity was minimal when gentamicin was injected during the feeding period, while the maximal toxicity was found when gentamicin was administered during the fasting period. It is concluded that the feeding period can modulate aminoglycoside nephrotoxicity. The time of dosing of gentamicin relative to the time of feeding seems to be a more important modulator of gentamicin nephrotoxicity than the light-dark cycle.

scholarly journals Validation of an efficient and continuous urodynamic monitoring system for awake, unrestrained, chronic rodent studies

2020 ◽  
Vol 318 (1) ◽  
pp. F86-F95
Author(s):  
D. Angoli ◽  
A. Geramipour ◽  
Z. C. Danziger
Keyword(s):  
Animal Studies ◽  
Measurement Problem ◽  
Automatic Monitoring ◽  
Bladder Volume ◽  
Bladder Function ◽  
Light Cycle ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Healthy Female ◽  
Surgical Recovery

The postvoid residual (PVR) is an important measure of bladder function, but obtaining PVR is burdensome because bladder volume must be measured at the time of voiding. The PVR measurement problem has led to experimental tricks in animal studies (infusing the bladder at supraphysiological rates and limiting animal observation windows) to keep the number of observed voids statistically robust while reducing the time an experimenter must be present. Our solution to the PVR measurement problem is a system called Automatic Monitoring for Efficient, Awake, Sensitive, Urine Residual Estimation (AMEASURE). AMEASURE combines metabolic cages and optimization algorithms to estimate continuously PVR for every voiding event 24 h/day for multiple weeks, without artificial bladder infusion, continuous experimenter supervision, anesthesia, or restraints. Using AMEASURE, we obtained voided volumes, PVRs, and other urodynamic parameters continuously for 21 days in 10 healthy female Sprague-Dawley rats. Importantly, this required only one manual measurement of animals’ bladder volume every 12 h. We validated the accuracy of the system experimentally and in simulation. We detected marked differences in voiding frequency and efficiency between light and dark cycles and found that voiding frequency increased over time during the dark cycle (but not the light cycle), due to surgical recovery, cage acclimation, and socialization. This tool enhances the relevance of rodent models to the study of human lower urinary tract by expanding observation periods and obviating the need to infuse the bladder and facilitates the study of conditions for which behavioral, social, or circadian factors play essential roles.

scholarly journals Organization of circadian rhythmicity and suprachiasmatic nuclei in malnourished rats

1997 ◽  
Vol 273 (4) ◽  
pp. R1321-R1331 ◽  
Author(s):  
Raúl Aguilar-Roblero ◽  
Alberto Salazar-Juarez ◽  
Julio Rojas-Castañeda ◽  
Carolina Escobar ◽  
León Cintra
Keyword(s):  
Drinking Behavior ◽  
Red Light ◽  
Immunohistochemical Analysis ◽  
Suprachiasmatic Nuclei ◽  
Sprague Dawley ◽  
Low Protein ◽  
Sprague Dawley Rats ◽  
Acid Protein ◽  
Coupling Force ◽  
Skeleton Photoperiod

The present study was aimed at characterizing the effects of low-protein malnutrition (6% casein) on the circadian rhythm of drinking behavior and on suprachiasmatic nuclei immunohistochemistry in Sprague-Dawley rats. Recordings were started at 30 days of age under a 12:12-h light-dark (LD) cycle. At age 150 days, recordings were continued under constant dim red light, and finally the latency to entrain to complete and skeleton photoperiods was established. At the end of the recordings rats were processed for histological analysis. Compared with their controls, malnournished rats exhibited 1) splitting of rhythmicity under LD that 2) condensed to one component in constant dim red light, 3) delayed entrainment to skeleton photoperiod, and 4) precocious entrainment under complete photoperiod. Immunohistochemical analysis showed mainly a decrease in the immunohistochemical detection of vasoactive intestinal polypeptide and glial fibrillar acid protein cells in malnourished animals. These results indicate that in malnourished rats there is a decrease 1) in the coupling force among the oscillators and 2) in the strength of the phase lock between the oscillators and the light-dark cycle.

scholarly journals Daily Variations in Ceftriaxone Pharmacokinetics in Rats

2003 ◽  
Vol 47 (2) ◽  
pp. 809-812 ◽  
Author(s):  
M. Rebuelto ◽  
L. Ambros ◽  
M. Rubio
Keyword(s):  
Time Of Day ◽  
Time Dependent ◽  
Pharmacokinetic Parameters ◽  
Dark Phase ◽  
Sprague Dawley ◽  
Dark Cycle ◽  
Once Daily ◽  
Daily Variations ◽  
Sprague Dawley Rats ◽  
Pharmacokinetics In Rats

ABSTRACT The aim of this study was to determine whether the time of day ceftriaxone was administered modified its pharmacokinetics. Ceftriaxone was given intraperitoneally at either 0400, 1000, 1600, and 2200 h to Sprague-Dawley rats synchronized under a light-dark cycle of 12 h of light and 12 h of dark. Pharmacokinetic parameters were analyzed for the presence of a 24-h rhythm. Results showed significant daily variations (P < 0.05) in ceftriaxone clearance, with the highest values during the dark phase. It is concluded that time-dependent variations in ceftriaxone pharmacokinetics may affect the therapeutic efficacy of current once-daily dosing schedules.

Sign in / Sign up

Export Citation Format

Share Document