Choice of Rat Strain: A Comparison of the General Pathology and the Tumour Incidence in 2-year old Sprague-Dawley and Long-Evans Rats

1982 ◽  
pp. 298-303 ◽  
Author(s):  
P. Greaves ◽  
Y. Rabemampianina
Keyword(s):  
Sprague Dawley ◽  
Tumour Incidence ◽  
General Pathology ◽  
Rat Strain ◽  
Long Evans

Rat Strain and Sex Differences in Leptin Responses to Immobilization Stress

2006 ◽  
Vol 27 (3) ◽  
pp. 136-146 ◽  
Author(s):  
Rachel M. Ceballos ◽  
Martha M. Faraday ◽  
Laura Cousino Klein
Keyword(s):  
Immobilization Stress ◽  
Strain Differences ◽  
Baseline Period ◽  
Interactive Effects ◽  
Stress Exposure ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Rat Strain ◽  
Long Evans ◽  
Plasma Leptin

The effects of immobilization (IM) stress on plasma leptin levels and bodyweight in adult Sprague-Dawley (19 males, 20 females) and Long-Evans (20 males, 20 females) rats were investigated. Following a 10-day baseline period, half the animals from each experimental group were exposed to immobilization stress or no-stress 20 min/day for 21 days. Plasma leptin and corticosterone levels were measured following stress or no-stress exposure on the last day of the experiment. Corticosterone levels confirmed stress exposure. Important interactive effects of stress, strain, and sex on leptin and corticosterone levels were also observed. Specifically, females displayed higher leptin levels than did males, regardless of stress exposure. Strain interacted with stress such that stressed Long-Evans rats displayed higher leptin levels than did stressed Sprague-Dawley rats; there were no strain differences in leptin levels among nonstressed rats. Also, correlations between leptin and corticosterone were strain-specific. Results are discussed with respect to previously unreported strain differences in the effects of immobilization stress on circulating plasma leptin and the relevance to inconsistent findings in the human literature.

Hypertension with Mineralocorticoid Administration to the Long-Evans Rat

1979 ◽  
Vol 56 (2) ◽  
pp. 109-113 ◽  
Author(s):  
O. B. Holland ◽  
C. Gomez-Sanchez ◽  
T. Ziegler
Keyword(s):  
Sprague Dawley ◽  
Relative Resistance ◽  
Rat Strains ◽  
Deoxycorticosterone Acetate ◽  
Sprague Dawley Rats ◽  
Renal Enlargement ◽  
Rat Strain ◽  
Long Evans

1. The Carworth Long-Evans rat has been reported to develop adrenal-regeneration hypertension but not deoxycorticosterone acetate (DOCA) hypertension. Deficiency of a hypothalamic receptor for deoxycorticosterone which mediates saline polydipsia has been postulated to underlie this resistance. Since a mineralocorticoid etiology for adrenal-regeneration hypertension has been postulated and all mineralocorticoids are thought to act on common receptors, these previous reports are difficult to reconcile. 2. To determine if an absolute or relative resistance to mineralocorticoids is present, Charles River Long-Evans and Sprague-Dawley rats were given 40 mg (107 μmol) of DOCA pellets/rat or 250 μg (0·65 μmol) of 2α-methyl-9α-fluorocortisol/day subcutaneously. 3. Saline polydipsia occurred with both steroids with both rat strains, though significantly less with the Long-Evans rats. Both types of rats became hypertensive and developed cardiac and renal enlargement with both steroids. Hypertension developed more rapidly with 2α-methyl-9α-fluorocortisol. 4. Thus mineralocorticoid hypertension can be produced in the Charles River Long-Evans rat, and the development of adrenal-regeneration hypertension in this rat strain is not incompatible with a mineralocorticoid etiology for adrenal-regeneration hypertension.

scholarly journals The Effects of Strain and Estrous Cycle on Heroin- and Sucrose-Maintained Responding in Female Rats

2020 ◽  
Author(s):  
Karl T. Schmidt ◽  
Jessica L. Sharp ◽  
Sarah B. Ethridge ◽  
Tallia Pearson ◽  
Shannon Ballard ◽  
...  
Keyword(s):  
Estrous Cycle ◽  
Fixed Ratio ◽  
Female Rats ◽  
Schedules Of Reinforcement ◽  
Sprague Dawley ◽  
Rat Strains ◽  
Rat Strain ◽  
Long Evans ◽  
Dose Condition ◽  
Intravenous Catheters

AbstractHeroin intake decreases during the proestrus phase of the estrous cycle in female, Long-Evans rats. The purpose of this study was to (1) determine if proestrus-induced decreases in heroin intake extend across rat strains and (2) determine if proestrus-induced decreases in responding extend to a nondrug reinforcer. Female rats were implanted with intravenous catheters and trained to self-administer heroin. Estrous cycle was tracked daily for the duration of the study. During testing, Lewis, Sprague-Dawley, and Long Evans rats self-administered low (0.0025 mg/kg) and high (0.0075 mg /kg) doses of heroin (Experiment 1) and then self-administered sucrose (Experiment 2) on fixed ratio (FR1) schedules of reinforcement. Heroin intake decreased significantly during proestrus in all three rat strains under at least one dose condition; however, sucrose intake did not decrease during proestrus in any strain. These data indicate that responding maintained by heroin, but not a nondrug reinforcer, significantly decreases during proestrus in female rats and that these effects are consistent across rat strain.

Ultrastructural Investigation of Spontaneous Pituitary Adenomas in Aging Sprague-Dawley Rats

1982 ◽  
Vol 40 ◽  
pp. 216-217
Author(s):  
D. J. McComb ◽  
J. Beri ◽  
F. Zak ◽  
K. Kovacs
Keyword(s):  
Microscopic Study ◽  
Pituitary Adenomas ◽  
Wistar Rats ◽  
Microscopic Level ◽  
Sprague Dawley ◽  
Prolactin Cells ◽  
Light Microscopic Level ◽  
Ultrastructural Investigation ◽  
Sprague Dawley Rats ◽  
Long Evans

Investigation of the spontaneous pituitary adenomas in rat have been limited mainly to light microscopic study. Furth et al. (1973) described them as chromophobic, secreting prolactin. Kovacs et al. (1977) in an ul trastructural investigation of adenomas of old female Long-Evans rats, found that they were composed of prolactin cells. Berkvens et al. (1980) using immunocytochemistry at the light microscopic level, demonstrated that some spontaneous tumors of old Wistar rats could contain GH, TSH or ACTH as well as PRL.

scholarly journals Dietary conjugated linoleic acid (CLA) induces apoptosis of colonic mucosa in 1,2-dimethylhydrazine-treated rats: a possible mechanism of the anticarcinogenic effect by CLA

2001 ◽  
Vol 86 (5) ◽  
pp. 549-555 ◽  
Author(s):  
Hyun S. Park ◽  
Ji H. Ryu ◽  
Yeong L. Ha ◽  
Jung H. Y. Park
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Control Diet ◽  
Terminal Deoxynucleotidyl Transferase ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Tumour Incidence ◽  
Sprague Dawley Rats ◽  
Dietary Conjugated Linoleic Acid

One of the objectives of the present study was to investigate whether 1 % conjugated linoleic acid (CLA) in the diet reduced tumour incidence in the colon of 1,2-dimethylhydrazine (DMH)-treated rats. Colon cancer was induced by injecting 6-week-old, male, Sprague–Dawley rats with 15 mg/kg DMH twice per week for 6 weeks. They were fed either 1 % CLA or a control diet ad libitum for 30 weeks. Dietary CLA significantly decreased colon tumour incidence (P<0·05). Our second objective was to investigate whether apoptosis in the colon mucosa of DMH-treated rats was affected by the amount of dietary CLA and whether the changes in apoptosis were related to those in fatty acid-responsive biomarkers. For this purpose, rats were killed after being fed a diet containing 0 %, 0·5 %, 1 % or 1·5 % CLA for 14 weeks. CLA was undetected in the mucosa of rats fed the 0 % CLA diet and increased to 5·9 mg/g phospholipid in rats fed the 0·5 % diet. The apoptotic index estimated by the terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling technique was increased by 251 % and the 1,2-diacylglycerol content was decreased by 57 % in rats fed 0·5 % CLA. No further changes in these variables were observed when CLA in the diet was raised to 1·0 % or 1·5 %. However, dietary CLA decreased mucosal levels of prostaglandin E2, thromboxane B2 and arachidonic acid in a dose-dependent manner. The present data indicate that dietary CLA can inhibit DMH-induced colon carcinogenesis by mechanisms probably involving increased apoptosis.

scholarly journals Effects of cocaethylene on dopamine and serotonin synthesis in Long–Evans and Sprague–Dawley brains

1998 ◽  
Vol 804 (2) ◽  
pp. 316-319 ◽  
Author(s):  
Michael H Baumann ◽  
Judith M Horowitz ◽  
Mark B Kristal ◽  
German Torres
Keyword(s):  
Sprague Dawley ◽  
Serotonin Synthesis ◽  
Long Evans

Characterization of T-cell lymphomas in the Prague inbred Sprague-Dawley/cub rat strain: a model of spontaneous hematologic malignancy

1999 ◽  
Vol 31 (3) ◽  
pp. 1618-1619
Author(s):  
B Otová ◽  
M Sladká ◽  
J Damoiseaux ◽  
A Panczak ◽  
V Mandys ◽  
...  
Keyword(s):  
T Cell ◽  
Hematologic Malignancy ◽  
Sprague Dawley ◽  
T Cell Lymphomas ◽  
Rat Strain

scholarly journals Endoparasitic Infection in Laboratory Rat Strain, Long-Evans (Rattus norvegicus Berkenhout, 1769)

1970 ◽  
Vol 44 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Farhana Muznebin ◽  
Hamida Khanum ◽  
Zaibun Nessa ◽  
Dipa Islam
Keyword(s):  
Key Words ◽  
Rattus Norvegicus ◽  
Parasite Species ◽  
Hymenolepis Diminuta ◽  
Helminth Parasite ◽  
New Finding ◽  
Syphacia Muris ◽  
Rat Strain ◽  
Long Evans ◽  
Taxonomic Groups

In the present study, five helminth parasite species from two taxonomic groups were identified from Long-Evans (Rattus norvegicus Berkenhout, 1769). The cestodes were Vampirolepis nana Siebold, Hymenolepis diminuta Rud and nematodes were Citellina dispar Prendel, Heterakis spumosa Schneider and Syphacia muris Yamaguti. C. dispar is a new finding in Bangladesh. The highest prevalence of H. diminuta was recorded but the highest intensity was recorded in V. nana. The prevalence and intensity of V. nana was 56.25% and 65.11±13.23; H. dimisnuta was 72.92% and 4.37±0.89; C. dispar was 62.50% and 19.63 ±2.10; H. spumosa was 66.67% and 9.06±1.85; and S. muris was 64.58% and 24.65±2.60 respectively. Differences in prevalence and intensity due to sexes and seasons were also evaluated. Key words: Cestodes, Nematodes, Helminth, Prevalence, Intensity.     doi: 10.3329/bjsir.v44i1.2718 Bangladesh J. Sci. Ind. Res. 44(1), 109-116, 2009

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