scholarly journals Inhibition of ghrelin-induced feeding in rats by pretreatment with a novel dual orexin receptor antagonist

2017 ◽  
Vol 68 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Mariko So ◽  
Hirofumi Hashimoto ◽  
Reiko Saito ◽  
Yukiyo Yamamoto ◽  
Yasuhito Motojima ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Paraventricular Nucleus ◽  
Adult Male ◽  
Wistar Rats ◽  
Arcuate Nucleus ◽  
Lateral Hypothalamic Area ◽  
Double Immunostaining ◽  
Orexin A ◽  
Hypothalamic Area ◽  
Male Wistar Rats

Abstract Orexin-A and -B, and ghrelin are potent orexigenic peptides. The effects of ACT462206, a novel dual orexin receptor antagonist (DORA), on ghrelin-induced feeding were examined in adult male Wistar rats. Hyperphagia induced by the intracerebroventricular (icv) administration of ghrelin was significantly suppressed for at least 2 h by pretreatment with icv administration of DORA. A marked increase was observed in the number of neurons showing Fos immunoreactivity in the paraventricular nucleus, arcuate nucleus and lateral hypothalamic area (LHA), 90 min after icv administration of ghrelin. Pretreatment with DORA significantly decreased the number of Fos-immunoreactive (IR) neurons; however, Fos immunoreactivity remained significantly increased. Double-immunostaining for Fos and orexin-A showed that many orexin-A-IR neurons in the LHA coexisted with Fos immunoreactivity after icv administration of ghrelin, but their number was reduced significantly by DORA pretreatment. These results suggest that centrally administered ghrelin may activate the orexinergic and non-orexinergic pathways responsible for the regulation of feeding.

scholarly journals GABA and glycine receptors in the nucleus ambiguus mediate tachycardia elicited by chemical stimulation of the hypothalamic arcuate nucleus

2015 ◽  
Vol 309 (1) ◽  
pp. H174-H184 ◽  
Author(s):  
Vineet C. Chitravanshi ◽  
Kazumi Kawabe ◽  
Hreday N. Sapru
Keyword(s):  
Paraventricular Nucleus ◽  
Wistar Rats ◽  
Arcuate Nucleus ◽  
Chemical Stimulation ◽  
Nucleus Ambiguus ◽  
Glycine Receptors ◽  
Inhibitory Neurotransmitters ◽  
Hypothalamic Arcuate Nucleus ◽  
Male Wistar Rats ◽  
Stimulation Of

We have previously reported that stimulation of the hypothalamic arcuate nucleus (ARCN) by microinjections of N-methyl-d-aspartic acid (NMDA) elicits tachycardia, which is partially mediated via inhibition of vagal inputs to the heart. The neuronal pools and neurotransmitters in them mediating tachycardia elicited from the ARCN have not been identified. We tested the hypothesis that the tachycardia elicited from the ARCN may be mediated by inhibitory neurotransmitters in the nucleus ambiguus (nAmb). Experiments were done in urethane-anesthetized, artificially ventilated, male Wistar rats. In separate groups of rats, unilateral and bilateral microinjections of muscimol (1 mM), gabazine (0.01 mM), and strychnine (0.5 mM) into the nAmb significantly attenuated tachycardia elicited by unilateral microinjections of NMDA (10 mM) into the ARCN. Histological examination of the brains showed that the microinjections sites were within the targeted nuclei. Retrograde anatomic tracing from the nAmb revealed direct bilateral projections from the ARCN and hypothalamic paraventricular nucleus to the nAmb. The results of the present study suggest that tachycardia elicited by stimulation of the ARCN by microinjections of NMDA is mediated via GABAA and glycine receptors located in the nAmb.

scholarly journals The role of hypothalamic ingestive behavior controllers in generating dehydration anorexia: a Fos mapping study

2008 ◽  
Vol 295 (4) ◽  
pp. R1009-R1019 ◽  
Author(s):  
Dawna Salter-Venzon ◽  
Alan G. Watts
Keyword(s):  
Paraventricular Nucleus ◽  
Arcuate Nucleus ◽  
Sensory Information ◽  
Lateral Hypothalamic Area ◽  
Ingestive Behavior ◽  
Lateral Part ◽  
Feeding Response ◽  
Hypothalamic Area ◽  
Lateral Hypothalamic ◽  
Afferent Inputs

Giving rats 2.5% saline to drink for 3–5 days simply and reliably generates anorexia. Despite having the neurochemical and hormonal markers of negative energy balance, dehydrated anorexic rats show a marked suppression of spontaneous food intake, as well as the feeding that is usually stimulated by overnight starvation or a 2-deoxy-d-glucose (2DG) challenge. These observations are consistent with a dehydration-dependent inhibition of the core circuitry that controls feeding. We hypothesize that this inhibition is directed at those neurons in the paraventricular nucleus and lateral hypothalamic area that constitute the hypothalamic “behavior controller” for feeding rather than their afferent inputs from the arcuate nucleus or hindbrain that convey critical feeding-related sensory information. To test this hypothesis, we mapped and quantified the Fos-immunoreactive response to 2DG in control and dehydrated rats drinking 2.5% saline. Our rationale was that regions showing an attenuated Fos response to 2DG in dehydrated animals would be strong candidates as the targets of dehydration-induced suppression of 2DG feeding. We found that the Fos response to combined dehydration and 2DG was attenuated only in the lateral hypothalamic area, with dehydration alone increasing Fos in the lateral part of the paraventricular nucleus. In the arcuate nucleus and those regions of the hindbrain that provide afferent inputs critical for the feeding response to 2DG, the Fos response to 2DG was unaffected by dehydration. Therefore, dehydration appears to target the lateral hypothalamic area and possibly the lateral part of the paraventricular nucleus to suppress the feeding response to 2DG.

Insulin-induced endothelin release and vasoreactivity in hypertriglyceridemic and hypertensive rats

1999 ◽  
Vol 277 (1) ◽  
pp. H399-H404 ◽  
Author(s):  
Pilar Nava ◽  
Verónica Guarner ◽  
Rosalinda Posadas ◽  
Israel Pérez ◽  
Guadalupe Baños
Keyword(s):  
Drinking Water ◽  
Receptor Antagonist ◽  
Wistar Rats ◽  
Receptor Blocker ◽  
Hypertensive Rats ◽  
Contractile Responses ◽  
Femoral Arteries ◽  
Male Wistar Rats

Insulin-elicited endothelin release in hypertriglyceridemic, hypertensive, hyperinsulinemic (HTG) rats was shown. Weanling male Wistar rats were given 30% sucrose in their drinking water for 20–24 wk. In vitro contractions of aorta and femoral arteries were elicited with 40 mM KCl. Endothelin release induced with KCl plus 50 μU/ml insulin resulted in increases in contractile responses: 41 ± 5.9 and 57 ± 6% for control and 65.5 ± 6 and 95 ± 9% for HTG aortas and femoral arteries, respectively. The endothelin ETB-receptor blocker BQ-788 decreased responses to KCl + insulin by 39 ± 8 and 53 ± 5% in control and 48 ± 13 and 79 ± 3.5% in HTG aortas and femoral arteries, respectively. The ETA-receptor antagonist PD-151242 inhibited these responses by 12 ± 10 and 1 ± 9% in control and by 51.5 ± 9 and 58.5 ± 1% in HTG aortas and femoral arteries, respectively. These results suggest that endothelin may contribute to the hypertension in this model.

scholarly journals Anti‐Fertility Effects of Amlodipine in Adult Male Wistar Rats

2011 ◽  
Vol 25 (S1) ◽  
Author(s):  
Adelaja Abdulazeez Akinlolu ◽  
Olaide Ghazali ◽  
Adebayo Kehinde Adefule
Keyword(s):  
Adult Male ◽  
Wistar Rats ◽  
Male Wistar Rats

scholarly journals Azathioprine and Methotrexate impaired the morphology and functions of the testes in adult wistar rats

2014 ◽  
Vol 31 (02) ◽  
pp. 075-081
Author(s):  
A. Akinlolu ◽  
O. Akinola ◽  
P. Khobe ◽  
K. Obasi ◽  
O. Dada
Keyword(s):  
Adult Male ◽  
Wistar Rats ◽  
Follicle Stimulating Hormone ◽  
Physiological Saline ◽  
Seminiferous Tubules ◽  
Control Group ◽  
Connective Tissues ◽  
Group I ◽  
Male Wistar Rats ◽  
Dose Dependent

Abstract Introduction: AAzathioprine and Methotrexate are both used in the treatment of cancer; and are classified as cytotoxic drugs with reported adverse effects such as oxidative damage to the DNA/RNA, the testes and sperm cells. This study, therefore, tested the hypothesis that AAzathioprine and Methotrexate administrations impair the morphology and functions of the testes in adult male wistar rats. Methods: AAzathioprine (50-150mg per day) and Methotrexate (2.5mg per week) are used in the treatment of cancer in adult Man. We tested the hypothesis that AAzathioprine and Methotrexate impair the morphology and functions of testes in rats. Forty adult male wistar rats (150-230g) were employed in the study: Control Group I received physiological saline while Experimental Groups II - V received oral administrations of 5mg/kg/bodyweight of AAzathioprine per day, 15mg/kg/bodyweight of AAzathioprine per day, 8mg/kg/bodyweight of Methotrexate per week and 20mg/kg/bodyweight of Methotrexate per week respectively for 35 days. Results: Histological examinations of the testes of rats of Groups II - V showed dose-dependent morphological anomalies such as fewer collagen ibers of connective tissues, disrupted seminiferous tubules and scanty spermatozoa when compared to rats of Group I. Statistical analyses showed dose-dependent elevated levels (P≤0.05) of superoxide dismutase and malondialdehyde in testes homogenates of rats of Groups II - V when compared to rats of Group I. This implied increased oxidative stress in rats of Groups II - V. Evaluations of Follicle Stimulating Hormone and Testosterone showed dose-dependent significantly elevated levels (P≤0.05) in rats of Groups II - V when compared to rats of Group I. Conclusions: Our findings are consistent with the stated hypothesis.

scholarly journals Avoidance memory requires CaMKII activity to persist after recall

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Andressa Radiske ◽  
Maria Carolina Gonzalez ◽  
Janine I. Rossato ◽  
Gênedy Apolinário ◽  
João R. de Oliveira ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Adult Male ◽  
Wistar Rats ◽  
Memory Reconsolidation ◽  
Memory Processing ◽  
Conflicting Information ◽  
Male Wistar Rats ◽  
Avoidance Memory ◽  
Avoidance Responses

AbstractAvoidance memory is destabilized when recalled concurrently with conflicting information, and must undergo a hippocampus-dependent restabilization process called reconsolidation to persist. CaMKII is a serine/threonine protein kinase essential for memory processing; however, its possible involvement in avoidance memory reconsolidation has not yet been studied. Using pharmacological, electrophysiological and optogenetic tools, we found that in adult male Wistar rats hippocampal CaMKII is necessary to reconsolidate avoidance memory, but not to keep it stored while inactive, and that blocking reconsolidation via CaMKII inhibition erases learned avoidance responses.

Chronic consumption of Hypericum humifusum leaf extracts impairs epididymis spermatozoa characters in association with oxidative stress in adult male Wistar rats

2017 ◽  
Vol 93 ◽  
pp. 616-625 ◽  
Author(s):  
Imen Hammami ◽  
Ridha Ben Ali ◽  
Afef Nahdi ◽  
Olfa Kallech-Ziri ◽  
Marwa Boussada ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Adult Male ◽  
Wistar Rats ◽  
Leaf Extracts ◽  
Male Wistar Rats

Anticonvulsive and anti-epileptogenesis effects of Echinacea purpurea root extract, an involvement of CB2 receptor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Masoumeh Gholami ◽  
Jamal Amri ◽  
Saeed Pazhoohan ◽  
Mehdi Sadegh
Keyword(s):  
Mortality Rate ◽  
Receptor Antagonist ◽  
Wistar Rats ◽  
Echinacea Purpurea ◽  
Root Extract ◽  
Cb2 Receptor ◽  
Kindling Model ◽  
Male Wistar Rats ◽  
Clonic Seizures ◽  
Cb2 Receptors

Abstract Objective Phytocannabinoids beyond the Δ9-tetrahy-drocannabinol have shown anticonvulsive effects. Also, alkylamides from Echinacea purpurea have been proved as cannabinomimetics. We examined the effect of the hydroalcoholic root extract of E. purpurea on pentylenetetrazol (PTZ)-induced tonic–clonic seizures and kindling model of epileptogenesis and the involvement of CB2 receptors as the mediator of this effect. Methods Male Wistar rats (200 ± 20 g) were used. Single intraperitoneal (i.p.) injection of PTZ (80 mg/kg) was used to induce tonic–clonic seizures. The kindling model of epileptogenesis was induced by daily injections of PTZ (37 mg/kg; i.p. for 15 days). Latency and duration of the stages were monitored for analysis. The hydroalcoholic root extract of E. purpurea was injected (i.p.) 20 min before seizure induction at the doses of 10, 50, 100 and 200 mg/kg. CB2 receptor antagonist SR144528 was injected (0.1 mg/kg; i.p.) 20 min before the Echinacea injection. Results In the tonic–clonic model, pretreatment with E. purpurea at the doses of 100 and 200 mg/kg significantly increased latencies to S2–S6, while it significantly decreased S6 duration and mortality rate. SR144528 injection before the injection of 100 mg/kg of E. purpurea significantly prevented the effects of the extract on S4–S6 latencies. In the kindling model, E. purpurea at the doses of 100 and 200 mg/kg significantly delayed epileptogenesis and decreased mortality rate, while SR144528 injection before the injection of 100 mg/kg of E. purpurea significantly blocked this effect of the extract. Conclusion These findings revealed the anticonvulsive and antiepileptogenesis effects of the E. purpurea root extract, which can be mediated by CB2 receptors.

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