Strain and Sex Differences in Gastric Ulceration in Restrained Rats

1967 ◽  
Vol 16 (3) ◽  
pp. 310-316 ◽  
Author(s):  
T. R. Wilson
Keyword(s):  
Sex Differences ◽  
Wistar Rats ◽  
Physical Restraint ◽  
Gastric Ulceration ◽  
Female Rats ◽  
Ulcer Formation ◽  
Sprague Dawley ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Different Strains

SummaryMale and female rats of three different strains were subjected to physical restraint, when it was demonstrated that there is a relationship between the strain of the rat and its susceptibility to gastric ulcer formation. Severity of ulceration was greatest in Wistar rats. Hooded Wistar rats were also ulcer-susceptible, but not to such a great extent as Wistar animals. Sprague-Dawley rats were resistant to ulcer formation. Sex differences in ulcer severity were found only with restrained Hooded Wistar rats.The results of this investigation compare favourably with results published for individual strains of rats by other workers. It is possible that genetic influences may be responsible for the differences observed, but the way in which they operate is not understood.

Maximum oxygen consumption of rats and its changes with various experimental procedures

1979 ◽  
Vol 47 (6) ◽  
pp. 1278-1283 ◽  
Author(s):  
T. G. Bedford ◽  
C. M. Tipton ◽  
N. C. Wilson ◽  
R. A. Oppliger ◽  
C. V. Gisolfi
Keyword(s):  
Test Procedure ◽  
Repeated Measurements ◽  
Female Rats ◽  
Shr Rats ◽  
Sprague Dawley ◽  
Cross Sectional ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Wistar Kyoto ◽  
Different Strains

A ten-stage treadmill test was developed and standardized to secure the VO2max of male and female rats assigned to various cross-sectional and longitudinal experimental groups. Repeated measurements indicated that the test procedure was reliable and could be used for research purposes. When the test was used with different strains, the untrained Sprague-Dawley rats had significantly higher VO2max values than animals of the Wistar-Kyoto (WKY) or the Okamoto-Aoki (SHR) strains. Exercise schedules were evaluated that were similar to those previously used by various investigators and it was found that most were exercising their rats at levels exceeding 75% VO2max. After 6--10 wk of chronic exercise, significant increases in VO2max occurred that ranged between 12 and 26%. Longitudinal studies (1 yr) with hypertensive (SHR) rats revealed that it was more desirable to logarithmically evaluate the relationship between VO2max and body mass than by the conventional method of ml . kg-1 . min-1. When this approach was used with SHR animals, the VO2max differences between the sexes were not apparent until the animals were 1 yr of age. On the other hand, training by male SHR rats caused significant increases in VO2max regardless of the method used to express the results. It is recommended that future studies designed to elucidate exercise mechanisms in rats should include a standardized VO2max test.

The growth and antigenicity of the metacestodes of Taenia crassiceps in several different strains of rats

1981 ◽  
Vol 55 (3) ◽  
pp. 209-222 ◽  
Author(s):  
J. Chernin
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Sprague Dawley ◽  
Taenia Crassiceps ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Antigenic Expression ◽  
Outbred Strain ◽  
Different Strains

ABSTRACTThe metacestodes of Taenia crassiceps removed from a stock infection of Sprague Dawley rats were injected into seven inbred and one outbred strain of rats. The results showed that over-all female rats are more susceptible to the infection than male rats. Only one strain of rat, the Lewis male rats, was found to be resistant to the infection. There was no significant difference in the volume of metacestodes recovered from the male and female rats. The sizes of the metacestodes, after two passages through the rats, were compared to those of the original mouse strain and it was found that metacestodes from two strains of rats were significantly smaller. The antigenic expression of the metacestodes from the different strains of rats was compared and some variation in the antigenicity was observed.

scholarly journals Sex Differences in Affective States and Association with Voluntary Ethanol Intake in Sprague Dawley Rats

2021 ◽  
Author(s):  
SG Quadir ◽  
GM Arleth ◽  
JV Jahad ◽  
M Echeveste Sanchez ◽  
MA Herman
Keyword(s):  
Sex Differences ◽  
The United States ◽  
Human Condition ◽  
Female Rats ◽  
Male Rats ◽  
Affective States ◽  
Sprague Dawley ◽  
Male And Female ◽  
Male And Female Rats ◽  
Sprague Dawley Rats

ABSTRACTAlcohol use disorders (AUDs) are a major problem across the United States. While AUD remains a complex human condition, it is difficult to isolate the directionality of anxiety and ethanol (EtOH) drinking from outside influences. The present study sought to investigate the relationship between affective states and EtOH intake using male and female Sprague Dawley rats. Using complementary tests of anxiety- and depressive-like behavior, we found sex- and test-specific differences in basal affective behavior such that females displayed enhanced anxiety-like behavior in the Splash Test and males displayed enhanced anxiety-like behavior in the Novelty Suppressed Feeding Test. Although there were no sex differences in EtOH intake and no correlation between anxiety-like behavior and subsequent EtOH intake, we did find that depressive-like behavior predicted future EtOH intake in females rats only. In addition, we observed an increase in depressive-like behavior is male rats in both the water and EtOH drinking groups. Furthermore, anxiety-like behavior, but not depressive-like behavior predicted subsequent EtOH intake in female rats. Lastly, we found a history of EtOH intake decreased pain thresholds in male and female rats. Together, these experiments provide important information on the complex interaction between negative affect and alcohol intake and how these two contexts reciprocally do, or do not, influence each other in a sex-specific manner.

scholarly journals A Safety Evaluation of a Nature-Identical l-Ergothioneine in Sprague Dawley Rats

2016 ◽  
Vol 35 (5) ◽  
pp. 568-583 ◽  
Author(s):  
Palma Ann Marone ◽  
Jan Trampota ◽  
Steven Weisman
Keyword(s):  
Body Weight ◽  
Body Weight Gain ◽  
Antioxidant Properties ◽  
Metabolic Activation ◽  
Female Rats ◽  
Systemic Absorption ◽  
Test Substance ◽  
Sprague Dawley ◽  
Male And Female Rats ◽  
Sprague Dawley Rats

l-(+) Ergothioneine is a naturally occurring thiol amino acid with antioxidant properties and potential benefits as a dietary supplement. Despite its century-old identification and wide distribution in human food, little is known of its mechanism of action and safety. The nature-identical biomimetic of l-(+) ergothioneine, produced by Mironova Labs and supplied as Mironova (EGT+), has been investigated in the present studies for its mutagenic and toxicologic potential. In a plate incorporation and preincubation assay with Salmonella typhimurium strains TA98, 100, 1,535, and 1,537 and Escherichia coli WP2uvrA strain, at dose concentrations of 1.58, 5, 15.8, 50, 158, 500, 1,580, and 5,000 μg/plate with and without metabolic activation, no cytotoxicity or mutagenicity was observed. Following a preliminary 28-day study, a repeated dose 90-day gavage study at dose levels of 0, 400, 800, and 1,600 mg/kg body weight (bw)/d in Sprague Dawley rats, in which dose-proportional systemic absorption was confirmed by plasma analysis, no adverse clinical, body weight/gain, food consumption and efficiency, clinical pathology, or histopathological changes associated with the administration of the nature-identical ergothioneine were observed. In conclusion, EGT+ administered over 90 days was well tolerated with a no adverse effect level at 1,600 mg/kg bw/d, the highest dose tested for male and female rats. In addition, the nature-identical test substance, EGT+ was not mutagenic in a bacterial reverse mutation assay at plate concentrations of up to 5,000 μg/mL in the presence or absence of metabolic activation.

scholarly journals Absorption, Distribution, Excretion, and Pharmacokinetics ofC-Pyronaridine Tetraphosphate in Male and Female Sprague-Dawley Rats

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Sang Hyun Park ◽  
Kannampalli Pradeep
Keyword(s):  
Clinical Trials ◽  
Small Intestine ◽  
Oral Administration ◽  
Female Rats ◽  
Sprague Dawley ◽  
Male And Female ◽  
Phase Ii Clinical Trials ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Peak Value

The main objective of this investigation was to determine the absorption, distribution, excretion, and pharmacokinetics of the antimalarial drug pyronaridine tetraphosphate (PNDP) in Sprague-Dawley rats. Following oral administration of a single dose (10 mg/Kg) ofC-PNDP, it was observed that the drug was readily absorbed from the small intestine within 1 hour following oral administration and was widely distributed in most of the tissues investigated as determined from the observed radioactivity in the tissues. The peak value of the drug in the blood was reached at around 8 hours postadministration, and radioactivity was detected in most of the tissues from 4 hours onwards.C-PNDP showed a poor permeability across the blood-brain barrier, and the absorption, distribution, and excretion ofC-PNDP were found to be gender-independent as both male and female rats showed a similar pattern of radioactivity. Excretion of the drug was predominantly through the urine with a peak excretion post 24 hours of administration. A small amount of the drug was also excreted in the feces and also in the breath. It was found that theCmax, AUC (0-inf), andTmaxvalues were similar to those observed in the Phase II clinical trials of pyronaridine/artesunate (Pyramax) conducted in Uganda.

EFFECT OF NEONATAL ADMINISTRATION OF THYROXINE ON THE RATE OF SEBUM PRODUCTION IN RATS

1979 ◽  
Vol 83 (2) ◽  
pp. 199-203 ◽  
Author(s):  
YEE CHU TOH
Keyword(s):  
Normal Activity ◽  
Skin Surface ◽  
Postnatal Period ◽  
Female Rats ◽  
Sprague Dawley ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Sebum Production ◽  
Skin Surface Lipids ◽  
Neonatal Administration

Newborn Sprague–Dawley rats of both sexes were treated with 28 μg thyroxine (T4) daily for the first week of life. At the age of 80 days, the secretion rate of sebum was measured from the amount of skin-surface lipids extractable by acetone and which had been produced during 2 days. Treatment with such excess amounts of T4 during the early postnatal period significantly reduced the production of sebum in both male and female rats when compared with control rats and with rats deprived of food early in life. The thyroid, the pituitary gland, the testes and the seminal vesicles were significantly smaller but the weights of the ovaries and uteri remained relatively unaffected. There was a similar ratio of sex difference in the rate of sebum secretion irrespective of treatment. It is suggested that a reduction of sebaceous response in rats made thyrotoxic with large doses of T4 early in life was probably due to a decreased secretion of thyroid hormone which is required to maintain normal activity of the sebaceous glands.

ROLE OF THE GONADS IN THE REGULATION OF SEBACEOUS GLANDS IN RATS: COMPARISON OF THE EFFECTS OF CASTRATION AT AND AFTER BIRTH

1980 ◽  
Vol 85 (2) ◽  
pp. 261-265 ◽  
Author(s):  
YEE CHU TOH
Keyword(s):  
Skin Surface ◽  
Female Rats ◽  
Sprague Dawley ◽  
Sebaceous Glands ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Sequential Event ◽  
Sebum Production ◽  
Skin Surface Lipids

Sprague–Dawley rats were castrated either within 24 h of birth or at 4 weeks of age. Control animals were sham operated. Intact female rats were also included for comparison. Sebum production was assessed at 80 days of age by measuring the amount of skin-surface lipids that could be extracted with acetone and which had been produced during 2 days. The removal of the testes at birth reduced the activity of the sebaceous glands to a level more nearly approaching that seen in the female rats whereas castration at 4 weeks of age only partially decreased the rate of sebum secretion so that it was intermediate between the male and female rats. The weights of the pituitary gland, thyroid and adrenal glands increased after castration but there were no differences between rats castrated at birth and those castrated at 4 weeks of age except in the weight of the thyroid gland. It would appear that the role of the testes in the control of the activity of the sebaceous glands is a sequential event which has already started at birth.

scholarly journals Intraperitoneal Alfaxalone and Alfaxalone–Dexmedetomidine Anesthesia in Sprague–Dawley Rats (Rattus norvegicus)

2020 ◽  
Vol 59 (5) ◽  
pp. 531-538
Author(s):  
Sylvia E West ◽  
Jonathan C Lee ◽  
Tinika N Johns ◽  
Elizabeth A Nunamaker
Keyword(s):  
Rattus Norvegicus ◽  
Female Rats ◽  
Male Rats ◽  
Sprague Dawley ◽  
Male And Female ◽  
Withdrawal Reflex ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Laboratory Rodent ◽  
Physiologic Parameters

Due to their unpredictability and variable effects, injectable anesthetic regimens in laboratory rodent species warrant refinement. In our study we sought to evaluate alfaxalone, which has gained recent popularity in veterinary medicine, alone and in combination with dexmedetomidine to evaluate their anesthetic ability in Sprague–Dawley rats when administered intraperitoneally. Three doses of alfaxalone only and 4 dose combinations of alfaxalone-dexmedetomidine were tested in males and female rats. The time to induction, anesthetic duration, pulse rate, respiratory rate, temperature, and time to recovery were recorded by a blind observer. The level of anesthesia induced by the various anesthetic protocols was assessed by using pedal withdrawal reflex to a noxious stimulus and scored according to the response. Dependent on the treatment group, atipamezole or saline was administered intraperitoneally once animals reached 60 min of anesthesia. Regardless of the dose, alfaxalone alone achieved only a sedative level of anesthesia, whereas all alfaxalone-dexmedetomidine combinations led to a surgical level of anesthesia in all animals. Anesthesia regimens using alfaxalone alone and in combination with dexmedetomidine demonstrated sex-associated differences, with female rats maintaining longer durations of sedation or anesthesia than their male counterparts. Both male and female rats displayed decreases in physiologic parameters consistent with the effects of dexmedetomidine. Given the results described herein, we recommend 20 mg/kg alfaxalone for sedation and 30 mg/kg alfaxalone combined with 0.05 mg/kg dexmedetomidine for surgical anesthesia in female rats. Appropriate doses of alfaxalone only and alfaxalone-dexmedetomidine for male rats were not determined in this study and need further evaluation.

Abstract 386: Compound 21 Induces Natriuresis via Renal AT2 Receptor Activation in Male and Female Rats

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Brandon A Kemp ◽  
Nancy L Howell ◽  
Robert M Carey
Keyword(s):  
Receptor Activation ◽  
Female Rats ◽  
Male Rats ◽  
Sprague Dawley ◽  
Male And Female ◽  
Male And Female Rats ◽  
Sprague Dawley Rats ◽  
Angiotensin Iii ◽  
Compound 21 ◽  
Renal Cortical Interstitium

Endogenous renal des-aspartyl 1 -angiotensin II (angiotensin III) activates renal proximal tubule AT 2 receptors (AT 2 Rs) and induces natriuresis via a nitric oxide-cyclic GMP signaling pathway. The present study explores the ability of highly selective non-peptide AT 2 R agonist Compound 21 (C21) to induce natriuresis. Sprague-Dawley rats (12 weeks old; male N=22; female N=18) were studied in the presence and absence of concurrent 24-h AT 1 R blockade with candesartan (CAND;0.01 mg/kg/min). Rats were anesthetized with Inactin 100 mg/kg i.p., uninephrectomized and instrumented for delivery of 3 cumulative 30-min i.v. infusions of C21 (100, 200, and 300 ng/kg/min) following a 30-min control infusion of vehicle. Mean arterial pressure (MAP) was measured for all periods and urine Na + excretion rate (U Na V) was calculated for the control and final C21 collection periods. To determine whether the systemically induced natriuresis is mediated by renal AT 2 Rs, PD-123319 (PD), a specific AT 2 R antagonist, was infused directly into the renal cortical interstitium(20 μg/kg/min and 10 μg/kg/min for females and males, respectively) during the i.v. C21 infusions. In female rats, C21 increased U Na V from 1.5 ± 0.20 to 7.48 ± 0.95 μmol/min (P<0.0001). This response was abrogated by concurrent intrarenal PD infusion [control 0.74 ± 0.19 vs. C21 2.02 ± 0.50 μmol/min (P<0.001from C21 alone). Systemic CAND administration augmented the natriuretic response to C21 [control 1.29 ± 0.25 vs. C21 10.68 ± 0.70 μmol/min (P<0.05 from C21 alone)]. In male rats, C21 increased U Na V from 0.46 ±0.08 to 6.21 ± 1.33 μmol/min (P<0.01). This response was blocked by concurrent intrarenal PD infusion [control 0.39 ± 0.11 vs. C21 1.69 ± 0.53 μmol/min (P<0.05 from C21 alone). Systemic CAND did not significantly alter the natriuretic response to C21 alone [control 0.49 ± 0.15 vs. C21 7.67 ± 0.72 μmol/min (P = NS from C21 alone). In female rats, CAND augmented the natriuretic response to C21 over that of male rats (P<0.01). Systemic arterial pressures were decreased by CAND in both male and female rats but were unchanged by C21 alone or together with intrarenal PD. C21 induces natriuresis via renal AT 2 R activation in both male and female rats. These data suggest the potential for AT 2 R agonist therapy in hypertension.

Influences of chemical sympathectomy and simulated weightlessness on male and female rats

1991 ◽  
Vol 71 (3) ◽  
pp. 1005-1014 ◽  
Author(s):  
C. R. Woodman ◽  
C. S. Stump ◽  
J. A. Stump ◽  
L. A. Sebastian ◽  
Z. Rahman ◽  
...  
Keyword(s):  
Weight Bearing ◽  
Mechanical Efficiency ◽  
Female Rats ◽  
Plasma Norepinephrine ◽  
Chemical Sympathectomy ◽  
Simulated Weightlessness ◽  
Sprague Dawley ◽  
Male And Female ◽  
Male And Female Rats ◽  
Sprague Dawley Rats

Maximum oxygen consumption (VO2max) has been shown to be reduced after periods of simulated weightlessness. To assess the role of the sympathetic nervous system in these reductions, Sprague-Dawley rats were either chemically sympathectomized (SYMX) or injected with saline (SHAM) and assigned to head-down suspension (HDS), horizontal restraint with the hindlimbs weight bearing (HWB), or cage-control (CC) conditions. VO2max, run time (RT), and mechanical efficiency (ME) were measured before suspension and on days 7 and 14. Male and female SHAM HDS groups exhibited reduced measures of VO2max (12–13%) after 7 and 14 days, and this decrease was attenuated in the SYMX and HWB rats. HDS resulted in a significant reduction in RT (9–15%) in both the male and female rats, and ME was significantly reduced after HDS in male and female SYMX and male SHAM rats (23–33%) but not in the female SHAM rats. Lesser reductions in ME were observed in the HWB rats. HDS and HWB were associated with lower body, fat-free, and fat masses, which were similar in male and female rats as well as for the SHAM and SYMX conditions. In a related HDS experiment with normal rats, plasma norepinephrine and epinephrine were increased by 53 and 42% after 7 days, but only epinephrine returned to baseline after 14 days. It was concluded that chemical sympathectomy and/or a weight-bearing stimulus will attenuate the loss in VO2max associated with simulated weightlessness in rats despite similar changes in body mass and composition. The mechanism(s) remains unclear at this time.

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