scholarly journals The Hypoactivity Associated with the Repeated Exposure to Atrazine Is Related to Decreases in the Specific Binding to D1-DA Receptors in the Striatum of Rats

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
José Abraham Márquez-Ramos ◽  
Isela Hernández-Plata ◽  
Mauricio Díaz-Muñoz ◽  
Verónica M. Rodríguez
Keyword(s):  
Ventral Striatum ◽  
Specific Binding ◽  
Dorsal Striatum ◽  
Nigrostriatal System ◽  
Saline Injection ◽  
Sprague Dawley ◽  
Da Receptors ◽  
Sprague Dawley Rats ◽  
Herbicide Atrazine ◽  
Short And Long Term

The herbicide atrazine (ATR) has a potential toxic effect on the neuronal circuits of the brain, specifically on two major dopaminergic pathways: the nigrostriatal and mesolimbic circuits. In this work, we repeatedly exposed adult male Sprague-Dawley rats to 6 injections of 100 mg ATR/kg of body weight (for two weeks) and one saline injection two days after ATR administration. Locomotor activity was assessed for 15 minutes and/or 2 hours after ATR or saline injection and 2 months after the final ATR administration. The specific binding of [3H]-SCH23390 to D1-DA receptors and that of [3H]-Spiperone to D2-DA receptors in the dorsal and ventral striatum were assessed 2 days and 2 months after ATR treatment. ATR administration resulted in immediate, short- and long-term hypoactivity and reduced specific binding of [3H]-SCH23390 in the dorsal striatum of rats evaluated 2 months after the last ATR injection. The specific binding of [3H]-SCH23390 in the ventral striatum and the specific binding of [3H]-Spiperone in the dorsal and ventral striatum remained unchanged at 2 days or 2 months after ATR treatment. These results, together with previous findings of our group, indicate that the nigrostriatal system is a preferential target for ATR exposure.

Comparative studies on tryptophan binding to hepatic nuclear envelopes in Sprague-Dawley and Lewis rats

1994 ◽  
Vol 267 (2) ◽  
pp. R502-R507 ◽  
Author(s):  
H. Sidransky ◽  
E. Verney
Keyword(s):  
Inflammatory Diseases ◽  
Specific Binding ◽  
Quantitative Difference ◽  
Sprague Dawley ◽  
Lewis Rats ◽  
Sprague Dawley Rats ◽  
Nuclear Rna ◽  
Eosinophilia Myalgia Syndrome

Since Lewis rats are susceptible to many inflammatory diseases and have been used in an experimental model of the eosinophilia-myalgia syndrome, we investigated whether Lewis rats would respond to L-tryptophan as have Sprague-Dawley rats reported earlier. In this comparative study using females of both strains, we observed a decrease in the affinity of in vitro L-tryptophan binding to hepatic nuclei and nuclear envelopes of Lewis rats compared with Sprague-Dawley rats. However, in vivo stimulatory effects of administering L-tryptophan on hepatic polyribosomal aggregation, protein synthesis, and nuclear RNA release were similar in both strains. In vitro [3H]tryptophan binding to hepatic nuclear envelopes, using L-tryptophan implicated in cases of the eosinophilia-myalgia syndrome, revealed less specific binding than when using nonimplicated L-tryptophan in both strains. The possible significance of the quantitative difference in the binding affinity of L-tryptophan to hepatic nuclei of Lewis rats compared with those of Sprague-Dawley rats is as yet undetermined.

Modulation of central glucocorticoid receptors in short- and long-term experimental hypothyroidism

2015 ◽  
Author(s):  
Elena Nikolopoulou ◽  
Dimitris Mytilinaios ◽  
Dimitris Spinos ◽  
Nikitas – Apollon Panagiotopoulos ◽  
George P. Chrousos
Keyword(s):  
Glucocorticoid Receptor ◽  
Binding Affinity ◽  
Glucocorticoid Receptors ◽  
Mrna Levels ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Receptor Number ◽  
Short And Long Term

Aim: Normal adrenocortical responsiveness to stress involves glucocorticoid negative feedback to terminate hypothalamic-pituitary-adrenal (HPA) axis activation. Hypothyroidism is associated with a centrally mediated adrenal insufficiency associated. The aim of this study was to examine whether this may be explained by a disturbed glucocorticoid feedback through specific brain receptors: the mineralocorticoid (MR) and glucocorticoid receptor (GR). Methods: Cytosolic receptor binding and gene expression was assessed in male Sprague-Dawley rats (350gm) with short- (7 days) and long-standing (60 days) hypothyroidism (thyroidectomy). Glucocorticoid receptor number and binding affinity in the hippocampus were measured using radioreceptor assay. In situ hybridization was employed to examine GR and MRmRNA levels in the hippocampus and the pituitary. Results: No differences in receptor number or affinity were observed after 7days and 60days treatment. Increased GRmRNA expression in the anterior pituitary was observed in 7day hypothyroid rats under basal conditions compared to euthyroid rats (122.77+4.93 vs 99.65+4.83 DPM/mg; p<0.05), which was associated with significantly decreased GRmRNA levels after osmotic stress (100.82+2.8 vs 110.48+4.1 DPM/mg; p<0.05). No differences were observed at 60days. No effect on MR mRNA expression in the hippocampus was seen in basal condition after both 7- and 60days hypothyroidism. MRmRNA was significantly decreased in 60 days-hypothyroid rats compared to euthyroid after normal saline (3995.67+131.54 vs 5121.00+505.2 DPM/mg; p<0.05). Conclusion: Hypothyroidism resulted in significant changes in GR and MR mRNA levels, in the hippocampus and the pituitary, without changes in receptor number and binding affinity.

scholarly journals Urolithiasis in the Sprague-Dawley rat

1979 ◽  
Vol 13 (1) ◽  
pp. 17-20 ◽  
Author(s):  
Michael Paterson
Keyword(s):  
General Interest ◽  
Sprague Dawley ◽  
Sprague Dawley Rat ◽  
Sprague Dawley Rats ◽  
Short And Long Term ◽  
Long Term Studies

A 7 year collection of calculi from short- and long-term studies with Sprague-Dawley rats showed that although the incidence of rats with urolithiasis was small (0·5%), the variety of sizes and composition of the calculi could be of general interest.

Growth characteristics of pulmonary artery smooth muscle cells from fawn-hooded rats

1995 ◽  
Vol 268 (3) ◽  
pp. L465-L470 ◽  
Author(s):  
K. Janakidevi ◽  
C. Tiruppathi ◽  
P. J. Del Vecchio ◽  
J. M. Pinheiro ◽  
A. B. Malik
Keyword(s):  
Smooth Muscle ◽  
Smooth Muscle Cells ◽  
Specific Binding ◽  
Pulmonary Arteries ◽  
Muscle Cells ◽  
Serum Concentrations ◽  
Egf Receptors ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Epidermal Growth

We compared the proliferative rates of vascular smooth muscle cells (VSMC) from pulmonary arteries of pulmonary hypertensive fawn-hooded rats (FHR) with VSMC from normotensive Sprague-Dawley rats (SDR). VSMC from FHR grew at increased rates and reached higher densities at all serum concentrations studied (5-20%) than the VSMC from SDR. The VSMC from FHR also responded to epidermal growth factor (EGF) at low serum concentrations, as evidenced by significantly greater DNA synthetic rates, than the control VSMC. The increased growth in these cells could be due to increased number and/or affinity of EGF receptors because of the higher specific binding of 125I-EGF to the VSMC from FHR. The VSMC from FHR and SDR were equally sensitive to the antiproliferative effects of heparin, suggesting that the heparin-sensitive pathways are not altered in the VSMC from FHR. These results suggest that the development of pulmonary hypertension in FHR may be related to the higher proliferative capacity of the pulmonary VSMC, which may be coupled to increased activity of the EGF receptors on these cells.

Neostigmine in the hippocampus increases thermogenesis and T4-to-T3 conversion

1996 ◽  
Vol 270 (6) ◽  
pp. R1215-R1219 ◽  
Author(s):  
M. Monda ◽  
A. Papa ◽  
G. Brizzi ◽  
B. DeLuca
Keyword(s):  
Firing Rate ◽  
Blood Level ◽  
Sympathetic Nerves ◽  
O2 Consumption ◽  
Saline Injection ◽  
Sprague Dawley ◽  
Interscapular Brown Adipose Tissue ◽  
Sprague Dawley Rats ◽  
Brown Adipose ◽  
Baseline Values

The firing rate of the nerves innervating interscapular brown adipose tissue (IBAT), IBAT and colonic temperatures (TIBAT and TC), and O2 consumption were monitored in urethan-anesthetized male Sprague-Dawley rats. These variables were measured for 40 min before (baseline values) and 40 min after a neostigmine (5 x 10(-7) mol) or saline injection in the hippocampus. The blood level of 3,5,3'-triiodothyronine and L-thyroxine (T3 and T4) and the 5'-deiodinating activity of IBAT, liver, and kidneys were determined in other rats with neostigmine or saline injection. The results showed that neostigmine injection increased firing rate, TIBAT, TC, O2 consumption, blood level of T3, and 5'-deiodinating activity of IBAT. No change was found in the T4 level and in 5'-deiodinating activity of the liver and kidneys. These findings suggest that neostigmine injection in the hippocampus increases heat production by stimulating sympathetic nerves to IBAT and by elevating the blood level of T3.

scholarly journals Oxycodone self-administration activates the mitogen-activated protein kinase/ mitogen- and stress-activated protein kinase (MAPK-MSK) signaling pathway in the rat dorsal striatum

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christopher A. Blackwood ◽  
Michael T. McCoy ◽  
Bruce Ladenheim ◽  
Jean Lud Cadet
Keyword(s):  
Protein Kinase ◽  
Histone H3 ◽  
Dorsal Striatum ◽  
Mitogen Activated Protein Kinase ◽  
Sprague Dawley ◽  
Self Administration ◽  
Molecular Analyses ◽  
Sprague Dawley Rats ◽  
Mitogen Activated Protein ◽  
Long Access

AbstractTo identify signaling pathways activated by oxycodone self-administration (SA), Sprague–Dawley rats self-administered oxycodone for 20 days using short—(ShA, 3 h) and long-access (LgA, 9 h) paradigms. Animals were euthanized 2 h after SA cessation and dorsal striata were used in post-mortem molecular analyses. LgA rats escalated their oxycodone intake and separated into lower (LgA-L) or higher (LgA-H) oxycodone takers. LgA-H rats showed increased striatal protein phosphorylation of ERK1/2 and MSK1/2. Histone H3, phosphorylated at serine 10 and acetylated at lysine 14 (H3S10pK14Ac), a MSK1/2 target, showed increased abundance only in LgA-H rats. RT-qPCR analyses revealed increased AMPA receptor subunits, GluA2 and GluA3 mRNAs, in the LgA-H rats. GluA3, but not GluA2, mRNA expression correlated positively with changes in pMSK1/2 and H3S10pK14Ac. These findings suggest that escalated oxycodone SA results in MSK1/2-dependent histone phosphorylation and increases in striatal gene expression. These observations offer potential avenues for interventions against oxycodone addiction.

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