scholarly journals Liberation of Serotonin Is Not Unaffected by Acetylcholine in Rat Hippocampus

2021 ◽  
Vol 25 (Suppl 2) ◽  
pp. S114-119
Author(s):  
Jae Heon Kim ◽  
Young Soo Ahn ◽  
Yun Seob Song

Purpose: Raised cerebral titers of acetylcholine have notable links with storage symptomatology related to lower urinary tract symptoms. The hippocampus contributes to the normal control of continence in the majority of instances (circuit 3). Owing to synaptic connections with other nerve cells, acetylcholine affects the micturition pathway via the liberation of additional cerebral neurotransmitters. Despite the fact that cerebral serotonin is a key inhibitor of reflex bladder muscle contractions, the influence of acetylcholine on its liberation is poorly delineated. The current research was conducted in order to explore the role of acetylcholine in serotonin liberation from sections of rat hippocampus in order to improve the comprehension of the relationship between cholinergic and serotonergic neurons.Methods: Hippocampal sections from 6 mature male Sprague-Dawley rats were equilibrated over a 30-minute period in standard incubation medium so as to facilitate [3H]5-hydroxytryptamine (5-HT) uptake. The cerebral neurotransmitter, acetylcholine, was applied to the sections. Aliquots of drained medium solution were utilized in order to quantify the radioactivity associated with [3H]5-HT liberation; any alterations in this parameter were noted.Results: When judged against the controls, [3H]5-HT liberation from the hippocampal sections remained unaltered following the administration of acetylcholine, implying that this agent has no inhibitory action on this process.Conclusions: Serotonin liberation from murine hippocampal sections is unaffected by acetylcholine. It is postulated that the bladder micturition reflex responds to acetylcholine through its immediate cholinergic activity rather than by its influence on serotonin release. These pathways are a promising target for the design of de novo therapeutic agents.

2011 ◽  
Vol 26 (S2) ◽  
pp. 652-652
Author(s):  
N. Ladurelle ◽  
C. Potard ◽  
C. Gabriel-Gracia ◽  
E. Mocaër ◽  
E. Beaulieu ◽  
...  

Neuronal plasticity alterations including cytoskeletal dynamics and synaptic markers have been recently associated with the treatment of major depression. Here we investigated the effects of agomelatine, a novel antidepressant with melatonergic (MT1/MT2) agonist and 5-HT2C receptor antagonist properties, on cytoskeletal microtubular proteins and synaptic markers in the rat hippocampus, prefrontal cortex (PFC) and amygdala.Adult male Sprague Dawley rats received daily i.p. administration of hydroxyethylcellulose 1% (vehicle) or agomelatine (40mg/kg) for 22 days. The rats were then sacrificed and hippocampi, PFC and amygdala dissected for analyses of microtubule dynamics markers (Tyr/Glu-Tub, Delta2-Tub and Acet-Tub) and synaptic markers (synaptophysin, PSD-95 and spinophilin) by Western blot.In the PFC, agomelatine decreased Tyr/Glu-Tub and the neuronal-specific Delta2-Tub, suggesting decreased microtubule dynamics. In contrast, in the hippocampus Tyr/Glu-Tub and Delta2-Tub were increased, indicative of enhanced microtubule dynamics. A similar pattern to those seen in the hippocampus, but of higher magnitude, was observed in the amygdala where an important increase of Tyr/Glu-Tub accompanied by a decrease of the stable form Acet-Tub was observed. These findings were paralleled by decreased hippocampal spinophilin (dendritic spines marker), increased synaptophysin (pre-synaptic marker) and spinophilin in the PFC and amygdala and increased PSD-95 (post-synaptic marker) in the amygdala, all consistent with synaptic remodelling phenomena.Taken together, these data shown that chronic agomelatine induces a differential modulation of microtubule dynamics and synaptic markers in the rat hippocampus, PFC and amygdala. These findings may have a particular relevance considering the fundamental role of these three brain areas in depression.


1997 ◽  
Vol 272 (1) ◽  
pp. F94-F99 ◽  
Author(s):  
G. W. Moeckel ◽  
Y. H. Lien

The trimethylamine glycine-betaine is accumulated to high concentrations in medullary cells of mammalian kidneys, whereas betaine synthesis from choline is predominant in the renal cortex. We investigated the contribution of renal betaine synthesis to medullary betaine accumulation. De novo synthesis of betaine in situ was accomplished by injecting [14C]choline into the renal artery of male Sprague-Dawley rats. [14C]betaine was measured in the renal cortex and medulla, as well as in serum and urine samples. Betaine concentration in the cortex decreased from 3.5 +/- 1.3 at 5 min to 0.4 +/- 0.2 nmol/mg protein at 60 min, but it increased from 1.4 +/- 0.1 to 2.5 +/- 0.6 nmol/mg protein in the medulla. Serum and total urine [14C]betaine increased from 2.7 +/- 1.3 and 0.9 +/- 0.1 nmol/ml at 5 min to 5.3 +/- 0.3 and 2.1 +/- 0.4 nmol/ml at 60 min, respectively. Concentrations of newly synthesized betaine were not decreased by the ligation of the hepatic artery and portal vein, suggesting that most [14C]betaine was synthesized in the kidney. Coinjection with 5 mM dimethylamino-ethanol, a choline oxidase inhibitor, and 100 mM cold betaine reduced medullary betaine accumulation by 80 and 76%, respectively. Water deprivation for 60 h increased both cortical and medullary [14C]betaine, whereas furosemide diuresis decreased the medullary [14C]betaine concentration. We concluded that betaine synthesized in the kidney can be accumulated in the medulla and that the medullary concentrations of newly synthesized betaine are closely related to the hydration state of the animal.


2011 ◽  
Vol 300 (5) ◽  
pp. H1781-H1787 ◽  
Author(s):  
Sachin S. Kandlikar ◽  
Gregory D. Fink

Excess sympathetic nervous system activity (SNA) is linked to human essential and experimental hypertension. To test whether sympathetic activation is associated with a model of deoxycorticosterone acetate (DOCA)-salt hypertension featuring two kidneys and a moderate elevation of blood pressure, we measured whole body norepinephrine (NE) spillover as an index of global SNA. Studies were conducted in chronically catheterized male Sprague-Dawley rats drinking water containing 1% NaCl and 0.2% KCl. After a 7-day surgical recovery and a 3-day control period, a DOCA pellet (50 mg/kg) was implanted subcutaneously in one group of rats (DOCA), while the other group underwent sham implantation (Sham). NE spillover was measured on control day 2 and days 7 and 14 after DOCA administration or sham implantation. During the control period, mean arterial pressure (MAP) was similar in Sham and DOCA rats. MAP was significantly increased in the DOCA group compared with the Sham group after DOCA administration ( day 14: Sham = 109 ± 5.3, DOCA = 128 ± 3.6 mmHg). However, plasma NE concentration, clearance, and spillover were not different in the two groups at any time. To determine whether selective sympathetic activation to the kidneys contributes to hypertension development, additional studies were performed in renal denervated (RDX) and sham-denervated (Sham-DX) rats. MAP, measured by radiotelemetry, was similar in both groups during the control and DOCA treatment periods. In conclusion, global SNA is not increased during the development of mild DOCA-salt hypertension, and fully intact renal nerves are not essential for hypertension development in this model.


1994 ◽  
Vol 267 (2) ◽  
pp. H751-H756 ◽  
Author(s):  
A. W. Cowley ◽  
E. Szczepanska-Sadowska ◽  
K. Stepniakowski ◽  
D. Mattson

Despite the well-recognized vasoconstrictor and fluid-retaining actions of vasopressin, prolonged administration of arginine vasopressin (AVP) to normal animals or humans fails to produce sustained hypertension. The present study was performed to elucidate the role of the V1 receptor in determining the ability of AVP to produce sustained hypertension. Conscious Sprague-Dawley rats with implanted catheters were infused with the selective V1 agonist, [Phe2,Ile3,Orn8]vasopressin (2 ng.kg-1.min-1), for 14 days in amounts that were acutely nonpressor. Blood pressure (MAP), heart rate (HR), body weight, and water intake (WI) were determined daily. Plasma AVP, plasma catecholamines norepinephrine and epinephrine, plasma osmolality, and electrolyte concentration were determined before and on days 1 and 7 of infusion. MAP increased significantly by 10.4 +/- 4.5 mmHg on day 1 and rose to 22 +/- 5 mmHg above control by day 14 (transient decrease on days 6-9) and then fell to control levels after the infusion was stopped. HR did not change significantly. Plasma AVP immunoreactivity increased from 2.5 +/- 0.3 to 10.9 +/- 2.1 pg/ml, whereas norepinephrine tended to fall only on day 1, with epinephrine only slightly elevated on day 7. No evidence of fluid retention was found, and rats lost sodium only on the first day of V1 agonist infusion. Body weight increased throughout the study but was unrelated to the changes of MAP. We conclude that chronic stimulation of V1 receptors results in sustained hypertension in rats.


2021 ◽  
Vol 17 ◽  
Author(s):  
Gideon Ayeni ◽  
Mthokozisi Blessing Cedric Simelane ◽  
Shahidul Islam ◽  
Ofentse Jacob Pooe

Background: Medicinal plants together with their isolated bioactive compounds are known for their antioxidant properties which constitute therapeutic agents that are routinely employed in the treatment of liver diseases. Aims of the Study: The current study sought to explore the protective role of Warburgia salutaris and its isolated compound, iso-mukaadial acetate against carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Thirty-five male Sprague Dawley rats were divided into seven groups of five animals each and injected with CCl4 to induce hepatic injury. Results: Treatment with the crude extract of W. salutaris and of iso-mukaadial acetate significantly reduced the levels of alkaline phosphatase, alanine and aspartate aminotransaminases, total bilirubin and malondialdehyde in a dose dependent manner, when compared to untreated groups. Liver histology revealed a reduction in hepatic necrosis and inflammation. Conclusion: The current investigation has demonstrated that W. salutaris extract and iso-mukaadial acetate could mitigate the acute liver injury inflicted by a hepatotoxic inducer in rats.


2006 ◽  
Vol 74 (7) ◽  
pp. 4387-4389 ◽  
Author(s):  
Rachel Marion ◽  
Asiya Baishanbo ◽  
Gilles Gargala ◽  
Arnaud François ◽  
Philippe Ducrotté ◽  
...  

ABSTRACT In 5-day-old immunocompetent Sprague-Dawley rats infected with either 102 or 105 Cryptosporidium parvum oocysts, transient infection resulted 120 days later in increased cardiovascular depressor response to jejunal distension and jejunal myeloperoxidase activity (P < 0.05). Nitazoxanide treatment normalized jejunal sensitivity (P < 0.001) but not myeloperoxidase levels (P > 0.05). Data warrant further evaluation of the role of early cryptosporidiosis in the development of chronic inflammatory gut conditions.


2021 ◽  
Vol 14 ◽  
Author(s):  
Xue-jia Li ◽  
Fei Zhu ◽  
Bo Li ◽  
Dong Zhang ◽  
Cheng-Wei Liang

Introduction: Osteoarthritis (OA) is a dominant cause of morbidity and disability. As a chronic disease, its etiological risk factors and most therapies at present, are empirical and symptomatic. Regenerating gene 4 (Reg4) is involved in cell growth, survival, regeneration, adhesion, and resistance to apoptosis, which are partially thought to be the pathogenic mechanisms of OA. However, the proper role of Reg4 in OA is still unknown. Methods: In this study, a consecutive administration of rhReg4 was applied to normal Sprague-Dawley rats or rats after OA induction. Histological changes and chondrocyte proliferation in the articular cartilage were measured. Results: We found that RhReg4 promotes chondrocyte proliferation in normal rats, and RhReg4 attenuated the severity of OA in rats by promoting chondrocytes’ proliferation in OA rats. Conclusion: In conclusion, recombinant human regenerating gene 4 (rhReg4) attenuates the severity of osteoarthritis in OA animal models and may be used as a new method for the treatment of osteoarthritis.


2021 ◽  
Author(s):  
Atta Mohammad Dost ◽  
Mehmet Gunata ◽  
Onural Ozhan ◽  
Azibe Yildiz ◽  
Nigar Vardi ◽  
...  

Abstract Amikacin (AK) is frequently used in the treatment of gram-negative and some gram-positive infections. However, its use is limited due to nephrotoxicity due to the increase in reactive oxygen radicals. The aim of this study was to investigate the role of carvacrol (CAR) against AK-induced nephrotoxicity in rats. Thirty-two Sprague Dawley rats were randomly divided into four groups as control (Vehicle), AK (400 mg/kg), CAR + AK (80 mg/kg CAR + 400 mg/kg AK), and AK + CAR (400 mg/kg AK + 80 mg/kg CAR) groups. AK and CAR were administered via intramuscular and per-oral for 7 days, respectively. Blood and kidney tissue samples were taken at the end of the experiment. Renal function and histopathological changes were compared, and the relevant parameters of oxidative stress and inflammation were detected. Histopathological findings (necrotic changes and dilatation and inflammatory cell infiltration) significantly increased in the AK group compared to the control group. Also, the rats in the AK group lost weight significantly. It was found that CAR treatment before and after AK significantly improved nephrotoxicity histopathologically (p < 0.05). However, this improvement was not detected biochemically. These results show that CAR treatment before and after AK improves nephrotoxicity in the histopathological level.


Toxins ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 398 ◽  
Author(s):  
Tarana Arman ◽  
Katherine D. Lynch ◽  
Michelle L. Montonye ◽  
Michael Goedken ◽  
John D. Clarke

Microcystin-LR (MCLR) is a hepatotoxic cyanotoxin reported to cause a phenotype similar to nonalcoholic steatohepatitis (NASH). NASH is a common progressive liver disease that advances in severity due to exogenous stressors such as poor diet and toxicant exposure. Our objective was to determine how sub-chronic MCLR toxicity affects preexisting diet-induced NASH. Sprague-Dawley rats were fed one of three diets for 10 weeks: control, methionine and choline deficient (MCD), or high fat/high cholesterol (HFHC). After six weeks of diet, animals received vehicle, 10 µg/kg, or 30 µg/kg MCLR via intraperitoneal injection every other day for the final 4 weeks. Incidence and severity scoring of histopathology endpoints suggested that MCLR toxicity drove NASH to a less fatty and more fibrotic state. In general, expression of genes involved in de novo lipogenesis and fatty acid esterification were altered in favor of decreased steatosis. The higher MCLR dose increased expression of genes involved in fibrosis and inflammation in the control and HFHC groups. These data suggest MCLR toxicity in the context of preexisting NASH may drive the liver to a more severe phenotype that resembles burnt-out NASH.


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