scholarly journals Effects of Δ9-tetrahydrocannabinol (THC) vapor inhalation in Sprague-Dawley and Wistar rats

2019 ◽  
Author(s):  
Michael A. Taffe ◽  
K. M. Creehan ◽  
Sophia A. Vandewater ◽  
Tony M. Kerr ◽  
Maury Cole
Keyword(s):  
Propylene Glycol ◽  
Plasma Levels ◽  
Intraperitoneal Injection ◽  
Wistar Rats ◽  
Indirect Comparison ◽  
Strain Differences ◽  
Sprague Dawley ◽  
Differential Impact ◽  
Sd Rats ◽  
Dose Dependent

AbstractA novel inhalation system based on e-cigarette technology has been recently shown to produce hypothermic and anti-nociceptive effects of Δ9-tetrahydrocannabinol (THC) in rats. Indirect comparison of some prior investigations suggested differential impact of inhaled THC between Wistar (WI) and Sprague-Dawley (SD) rats, thus this study was conducted to directly compare the strains.Groups (N=8 per strain) of age matched male SD and WI rats were prepared with radiotelemetry devices to measure temperature and then exposed to vapor from the propylene glycol (PG) vehicle or THC (25, 100, 200 mg/mL of PG) for 30 or 40 minutes. Additional studies evaluated plasma THC levels and anti-nociceptive effects after THC inhalation as well as the thermoregulatory effect of intraperitoneal injection of THC (5-30 mg/kg).Hypothermic effects of inhaled THC was more pronounced in SD rats however plasma levels of THC were identical across strains under either fixed inhalation conditions or injection of a mg/kg equivalent dose. Strain differences in hypothermia were even more pronounced after i.p. injection of THC with SD rats exhibiting dose-dependent temperature reduction after 5 or 10 mg/kg, i.p. and the WI rats only exhibiting significant hypothermia after 20 mg/kg, i.p. The anti-nociceptive effects of inhaled THC (100, 200 mg/mL) did not differ significantly across the strains. These studies confirm an insensitivity of WI rats, compared with SD rats, to the hypothermia induced by THC following inhalation conditions that produced identical plasma THC and anti-nociception. Thus strain differences were not due to differential THC delivery via vapor inhalation.

Strain Differences Occurring in an Experimental Study of Punishment

1965 ◽  
Vol 16 (2) ◽  
pp. 531-536 ◽  
Author(s):  
Morton H. Kleban
Keyword(s):  
Experimental Study ◽  
Empirical Evidence ◽  
Wistar Rats ◽  
Strain Differences ◽  
Training Procedure ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Y Maze ◽  
Minimum Number ◽  
The Difference

Forty-three Sprague-Dawley and 43 Wistar rats were given reward training for 40 trials in a Y-maze. On the next 20 trials, control groups were continued under the same training procedure, and 50% shock trials were introduced in the training of the remaining rats. For the extinction training, the reward was shifted to the opposite arm and 50% shock was continued for the no-delay and 30-sec. delay shock groups. The most significant results were that in the 30-sec. delay groups, the delay helped the Sprague-Dawley rats reverse in a minimum number of trials, whereas the Wistar rats showed strong indications of response stereotypy. The findings with respect to the Sprague-Dawley rats supported the empirical evidence on the effectiveness of delay in overcoming response persistence and the findings on the Wistar rats supported the empirical evidence on omission in punishment. The difference in response to punishment between the two albino strains emphasizes the need for experimental study of strain factors. Experiments should be repeated with several animal strains to remedy over-generalization from single strains and to help elaborate our understanding of the interaction present between punishment and strains.

20-HETE-mediated vasoconstriction by hemoglobin-O2 carrier in Sprague-Dawley but not Wistar rats

2005 ◽  
Vol 98 (3) ◽  
pp. 772-779 ◽  
Author(s):  
Andrew D. Baines ◽  
Patrick Ho
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Blood Flow ◽  
Wistar Rats ◽  
Filtration Rate ◽  
Blood Substitutes ◽  
Sprague Dawley ◽  
Ringer Lactate ◽  
Sd Rats ◽  
Renal Vascular

Hypothetically either decreased nitric oxide (NO) or increased O2 could initiate 20-HETE-mediated vasoconstriction associated with hemoglobin-based blood substitutes (HBOC). To test this hypothesis, we infused Tm-Hb, an HBOC with low O2 affinity, into isoflurane-anesthetized Wistar (W) and Sprague-Dawley (SD) rats after exchanging 20% of their blood with Ringer lactate. For comparison we infused an equal amount of BSA or BSA with NG-nitro-l-arginine methyl ester (BSA+NAME). Tm-Hb increased blood pressure (BP) and renal vascular resistance (RVR) equally in W and SD rats. Renal blood flow (RBF; Doppler ultrasound) decreased. BSA decreased RVR and raised glomerular filtration rate. BSA+NAME raised BP, RVR, and GFR. HET0016, an inhibitor of 20-HETE production, blunted BP and RVR responses to Tm-Hb and BSA+NAME in SD but not W rats. Arterial O2 content with BSA was lower than with Tm-Hb but O2 delivery was 60% higher with BSA because of higher RBF. BSA raised Po2 (Oxylite) in cortex and medulla and reduced RVR. Tm-Hb decreased Po2 and increased RVR. Switching rats from breathing air to 100% O2 raised intrarenal Po2 two- to threefold and increased BP and RVR. HET0016 did not alter hyperoxic responses. In conclusion, 20-HETE contributes to vasoconstriction by Tm-Hb in SD but not in W rats, and increased 20-HETE activity results primarily from decreased NO.

scholarly journals Failure to upregulate the adenosine2A receptor-epoxyeicosatrienoic acid pathway contributes to the development of hypertension in Dahl salt-sensitive rats

2008 ◽  
Vol 295 (6) ◽  
pp. F1696-F1704 ◽  
Author(s):  
Elvira L. Liclican ◽  
John C. McGiff ◽  
John R. Falck ◽  
Mairéad A. Carroll
Keyword(s):  
Renal Perfusion ◽  
Epoxyeicosatrienoic Acid ◽  
Sprague Dawley ◽  
Salt Loading ◽  
Vasodilator Response ◽  
Sd Rats ◽  
Acid Pathway ◽  
Salt Sensitive Hypertension ◽  
Dose Dependent

Adenosine-activated renovascular dilatation in Sprague-Dawley (SD) rats is mediated by stimulating adenosine2A receptors (A2AR), which is linked to epoxyeicosatrienoic acid (EET) synthesis. The A2AR-EET pathway is upregulated by high salt (HS) intake in normotensive SD rats. Because this pathway is antipressor, we examined the role of the A2AR-EET pathway in Dahl salt-sensitive (SS) rats. Male Dahl salt-resistant (SR) and SS rats were fed either HS (8.0% NaCl) or normal salt (NS; 0.4% NaCl) diet for 7 days. On day 8, isolated kidneys were perfused with Krebs-Henseleit buffer containing indomethacin and NG-nitro-l-arginine methyl ester and preconstricted with phenylephrine. Bolus injections of the stable adenosine analog 2-chloroadenosine (2-CA; 0.1–20 μg) elicited dose-dependent dilation in both Dahl SR and SS rats. Dahl SR rats fed a HS diet demonstrated a greater renal vasodilator response to 10 μg of 2-CA, as measured by the reduction in renal perfusion pressure, than that of Dahl SR rats fed a NS diet (−104 ± 6 vs. −77 ± 7 mmHg, respectively; P < 0.05). In contrast, Dahl SS rats did not exhibit a difference in the vasodilator response to 2-CA whether fed NS or HS diet (96 ± 6 vs. 104 ± 13 mmHg in NS- and HS-fed rats, respectively). In Dahl SR but not Dahl SS rats, HS intake significantly increased purine flux, augmented the protein expression of A2AR and the cytochrome P-450 2C23 and 2C11 epoxygenases, and elevated the renal efflux of EETs. Thus the Dahl SR rat is able to respond to HS intake by recruiting EET formation, whereas the Dahl SS rat appears to have exhausted its ability to increase EET synthesis above the levels observed on NS intake, and this inability of Dahl SS rats to upregulate the A2AR-EET pathway in response to salt loading may contribute to the development of salt-sensitive hypertension.

scholarly journals Renal effects of recombinant prolactin in anaesthetized rats

2001 ◽  
pp. 65-71 ◽  
Author(s):  
SE Morrissey ◽  
T Newth ◽  
R Rees ◽  
A Barr ◽  
F Shora ◽  
...  
Keyword(s):  
Sodium Excretion ◽  
Sprague Dawley ◽  
Urine Excretion ◽  
Water Excretion ◽  
Renal Effects ◽  
Sd Rats ◽  
Anaesthetized Rats ◽  
Dose Dependent Decrease ◽  
Hereditary Hypothalamic Diabetes Insipidus ◽  
Dose Dependent

OBJECTIVE: To re-examine the controversial possibility that prolactin exerts renal effects, using recombinant mouse prolactin (rmP), in the presence and absence of circulating vasopressin. DESIGN: In experiment 1, the renal effects of rmP were examined in anaesthetized Brattleboro rats with hereditary hypothalamic diabetes insipidus (BDI) lacking circulating vasopressin and normal animals of the parent Long Evans (LE) strain. In experiment 2, salt and water excretion were studied in fluid-loaded normal Sprague-Dawley (SD) rats, some of which received rmP. METHODS: In experiment 1, BDI and LE rats maintained in fluid balance were infused i.v. with each of three concentrations of rmP (10, 20 and 40 microg/ml per h) or maintained on 150 mmol/l NaCl vehicle (controls). In experiment 2, the SD rats were infused with 75 mmol/l NaCl in order to induce a state of diuresis comparable to that of BDI rats, some of them then receiving the rmP i.v. RESULTS: A profound rmP-induced dose-dependent decrease in urine excretion (P<0.005) and a lesser decrease in sodium excretion in the BDI rats was in marked contrast with the small but significant increase in urine excretion in the LE rats compared with controls (P<0.025). The rmP-infused fluid-loaded SD rats also demonstrated a significant (P<0.05) dose-related antidiuresis compared with the control animals, in addition to a decrease in sodium excretion. CONCLUSIONS: These results show that prolactin has a profound antidiuretic effect in the absence of circulating vasopressin. In contrast, when vasopressin is present in the circulation rmP has a small, but opposite, diuretic effect. Thus the use of a recombinant prolactin has provided evidence for renal effects of this hormone which are modified in the presence of the circulating neurohypophysial hormone vasopressin.

scholarly journals Strain differences in purified rat hepatic 3 α-hydroxysteroid UDP-glucuronosyltransferase

1985 ◽  
Vol 230 (2) ◽  
pp. 403-409 ◽  
Author(s):  
M D Green ◽  
C N Falany ◽  
R B Kirkpatrick ◽  
T R Tephly
Keyword(s):  
Individual Differences ◽  
Chenodeoxycholic Acid ◽  
Wistar Rats ◽  
Glucuronic Acid ◽  
Strain Differences ◽  
Sprague Dawley ◽  
Qualitative And Quantitative ◽  
Sprague Dawley Rats ◽  
Different Populations ◽  
Udp Glucuronosyltransferase

Qualitative and quantitative differences of purified hepatic 3 α-hydroxysteroid UDP-glucuronosyltransferase were investigated in Wistar and Sprague-Dawley rats. Individual differences in the glucuronidation rate of androsterone and chenodeoxycholic acid were observed in hepatic microsomal fractions from Wistar but not Sprague-Dawley rats. No individual variation was observed in the glucuronidation of testosterone, p-nitrophenol or oestrone. The 3 α-hydroxysteroid UDP-glucuronosyltransferases from livers of Wistar and Sprague-Dawley rats were isolated and highly purified by using Chromatofocusing and affinity chromatography. The amount of 3 α-hydroxysteroid UDP-glucuronosyltransferase in the liver of Wistar rats exhibiting low rates for androsterone glucuronidation is about 10% or less than that found in hepatic microsomal fractions obtained from Wistar rats having high rates for androsterone glucuronidation. The apparent Km for androsterone with purified 3 α-hydroxysteroid UDP-glucuronosyltransferase from Wistar rats with high glucuronidation activity (6 microM) was not different from that observed for the enzyme purified from Sprague-Dawley animals, whereas that for the enzyme purified from Wistar rats with low glucuronidation activity was substantially higher (120 microM). Despite the differences in apparent Km values for androsterone, the apparent Km for UDP-glucuronic acid (0.3 mM) was not different in the different populations of rats.

scholarly journals Differential Polarization of Tumor-Associated Macrophages/Microglia Drives the Aggressiveness of Gliomas

2021 ◽  
Author(s):  
Nai-Wei Yao ◽  
Hsiu-Ting Lin ◽  
Ya-Lin Lin ◽  
Khamushavalli Geeviman ◽  
Fang Liao ◽  
...  
Keyword(s):  
Tumor Microenvironment ◽  
Tumor Growth ◽  
Wistar Rats ◽  
Tumor Development ◽  
C6 Glioma ◽  
Sprague Dawley ◽  
Tumor Associated Macrophages ◽  
Sd Rats ◽  
Glioma Growth

Abstract Background: Glioblastoma is the most aggressive subtype of brain tumors. The major component of tumor microenvironment in glioblastoma is tumor-associated macrophages (TAMs), which are associated with enhanced malignancy of glioblastoma. The polarization of macrophages to the pro-inflammatory M1 or anti-inflammatory M2 subtypes governed by the context of tumor microenvironment may dictate the aggressiveness and outcome of glioblastoma. Given that the immune responses to tumors vary distinctively among individuals due to intrinsic, environmental and genetic factors and that TAMs display a high level of diversity and plasticity, we aimed to examine the effects of differential polarization of TAMs on the glioblastoma development by implanting C6 glioma into brains of Sprague–Dawley (SD) and Wistar rats; these two rats have different genetic background and host microenvironment during tumor development. Methods: Sprague–Dawley (SD) and Wistar rats were implanted with C6 glioma in the brain. The measurement of tumor volumes, tumor morphology and tumor growth in C6 glioma implanted brains were measured by multi-parametric magnetic resonance imaging (MRI). Immunofluorescence staining was performed to analyze tumor angiogenesis and M1 and M2 TAMs in C6 gliomas. Results: By multi-parametric MRI measurement, C6 gliomas developed in the SD rats were characterized with enlarged tumors, accompanied with shorter animal survival. In comparison to the gliomas in Wistar rats, the accelerated tumor growth in SD rats was associated with greater extent of angiogenesis accompanied with higher levels of VEGF/VEGFR2. In support, C6 gliomas in SD rats were filtrated with TAMs characterized with a higher M2/M1 ratio, in contrast to the TAMs of a high M1/M2 ratio in Wistar rats. Attempts were made to shift the M2/M1 balance. Administration of the cytokine IFN-γ that induces M1 TAMs to SD rats greatly suppressed glioma formation, accompanied with a remarkable increase of M1 TAMs. Administration of the cytokines IL-4 plus IL-10 that induces M2 TAMs significantly promoted glioma growth in the Wistar rats, associated with an increase in the M2 TAMs. Conclusions: These results demonstrate an important role of TAMs in glioma pathogenesis and the crucial role of microenvironment in dictating the polarization of TAMs, suggesting that targeting or repolarization of TAMs may serve as an effective intervention for gliomas.

scholarly journals Pinning in the Play Fighting of Rats: A Comparative Perspective With Methodological Recommendations

2016 ◽  
Vol 29 ◽  
Author(s):  
Stephanie M. Himmler ◽  
Brett T. Himmler ◽  
Rafał Stryjek ◽  
Klaudia Modlińska ◽  
Wojciech Pisula ◽  
...  
Keyword(s):  
Strain Differences ◽  
Competitive Interaction ◽  
The Other ◽  
Comparative Perspective ◽  
Sprague Dawley ◽  
Play Fighting ◽  
Sd Rats ◽  
Long Evans ◽  
Experimental Treatments ◽  
Pin Configuration

During play fighting, rats attack and defend the nape and during the course of this competitive interaction, they may adopt a configuration in which one animal stands over its supine partner (i.e., pin). Because the pin configuration is typically frequent and relatively easy to identify, it has been widely used as a marker to detect the effects of experimental treatments. In the present study, the frequency of pinning during standardized, 10min trials in three strains of rats, Long Evans hooded (LE), Sprague-Dawley (SD) and wild (WWCPS), was compared. LE and SD had higher rates than WWCPS rats (#/min: 6.5, 5.5, 1.5, respectively). When adjusted for strain differences in the frequency of attacks, SD as well as WWCPS rats had lower rates of pinning compared to LE rats. Both SD and WWCPS rats were less likely to use tactics of defense that promote pinning. Moreover, while the majority of the pins achieved in LE rats arose from the defender actively rolling over onto its back, the majority of pins in WWCPS rats arose because one partner pushed the other onto its back. SD rats were intermediate in this regard. Finally, once they do adopt the pin configuration, SD rats are less likely to remain supine than LE and WWCPS rats. That is, both SD and WWCPS rats have significantly fewer pins than LE rats, but a different combination of factors account for this. These data highlight the need to use a battery of measures for ascertaining the effects of experimental manipulations on play. Some suggested guidelines are provided.

The Effect of Age and Strain Differences on the Incidence of Restraint-Induced Oral and Gastric Ulcers in Three Strains of Rats

1972 ◽  
Vol 51 (2) ◽  
pp. 619-625 ◽  
Author(s):  
D.K. Whittaker ◽  
T.R. Wilson
Keyword(s):  
Wistar Rats ◽  
Strain Differences ◽  
Gastric Ulcers ◽  
Sprague Dawley ◽  
Oral Ulcers ◽  
Sprague Dawley Rats ◽  
Different Strains ◽  
Strain Dependent ◽  
Effect Of Age

Restraint of different strains of rat has been shown to be capable of inducing both oral and gastric ulcers. Hooded Wistar rats were most susceptible to gastric ulcers, whereas Sprague-Dawley rats had the highest incidence of oral ulcers. The causative mechanisms probably differ and are strain dependent.

RESPONSES OF TWO STRAINS OF RATS TO RAPESEED OIL AND CORN OIL

1960 ◽  
Vol 38 (3) ◽  
pp. 187-192 ◽  
Author(s):  
Joyce L. Beare ◽  
T. K. Murray ◽  
J. A. Campbell
Keyword(s):  
Vitamin A ◽  
Rapeseed Oil ◽  
Wistar Rats ◽  
Corn Oil ◽  
Strain Differences ◽  
Basal Diet ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Significant Difference ◽  
Dietary Oil

Wistar and Sprague–Dawley rats were compared in their response to 20% rapeseed oil or corn oil in a basal diet of ground fox cubes. Apparent coefficients of digestibility were significantly lower for rapeseed oil than for corn oil in the Sprague–Dawley, but not in the Wistar rats. After 6 weeks the adrenals of Sprague–Dawley rats were larger in the animals fed rapeseed oil than in those fed corn oil, while the adrenals of Wistar rats were not influenced by the dietary oil. These strain differences explain some discrepancies appearing in the literature concerning the effects of rapeseed oil in the rat.In another experiment, Wistar and Sprague–Dawley rats deprived of vitamin A for 18 days were fed a purified basal diet with 20% rapeseed oil or corn oil and dosed with 75 or 150 I.U. of vitamin A per day. After 14 days there was no significant effect of the strain of rat or the type of dietary oil on the liver storage of vitamin A. The rate of depletion of vitamin A from the liver following a single dose of 1200 I.U. of vitamin A was also studied and indicated no significant difference attributable to the dietary oils.

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