Systemic morphine administration causes gastric distention and hyperphagia in healthy horses

2019 ◽  
Vol 51 (5) ◽  
pp. 653-657
Author(s):  
C. Tessier ◽  
J.‐P. Pitaud ◽  
C. Thorin ◽  
G. Touzot‐Jourde
Keyword(s):  
Gastric Distention ◽  
Morphine Administration

Longterm morphine administration in newborn

2006 ◽  
Vol 210 (S 5) ◽  
Author(s):  
K Ruoss ◽  
A Gerber ◽  
M Albisetti ◽  
V Bernet
Keyword(s):  
Morphine Administration

scholarly journals The Paradoxical Effect Hypothesis of Abused Drugs in a Rat Model of Chronic Morphine Administration

2021 ◽  
Vol 10 (15) ◽  
pp. 3197
Author(s):  
Yinghao Yu ◽  
Alan Bohan He ◽  
Michelle Liou ◽  
Chenyin Ou ◽  
Anna Kozłowska ◽  
...  
Keyword(s):  
Drug Addiction ◽  
Basolateral Amygdala ◽  
Neural Substrates ◽  
Plasma Corticosterone ◽  
High Plasma ◽  
Paradoxical Effect ◽  
Chronic Morphine ◽  
Morphine Administration ◽  
Abused Drugs ◽  
Effect Hypothesis

A growing body of studies has recently shown that abused drugs could simultaneously induce the paradoxical effect in reward and aversion to influence drug addiction. However, whether morphine induces reward and aversion, and which neural substrates are involved in morphine’s reward and aversion remains unclear. The present study first examined which doses of morphine can simultaneously produce reward in conditioned place preference (CPP) and aversion in conditioned taste aversion (CTA) in rats. Furthermore, the aversive dose of morphine was determined. Moreover, using the aversive dose of 10 mg/kg morphine tested plasma corticosterone (CORT) levels and examined which neural substrates were involved in the aversive morphine-induced CTA on conditioning, extinction, and reinstatement. Further, we analyzed c-Fos and p-ERK expression to demonstrate the paradoxical effect—reward and aversion and nonhomeostasis or disturbance by morphine-induced CTA. The results showed that a dose of more than 20 mg/kg morphine simultaneously induced reward in CPP and aversion in CTA. A dose of 10 mg/kg morphine only induced the aversive CTA, and it produced higher plasma CORT levels in conditioning and reacquisition but not extinction. High plasma CORT secretions by 10 mg/kg morphine-induced CTA most likely resulted from stress-related aversion but were not a rewarding property of morphine. For assessments of c-Fos and p-ERK expression, the cingulate cortex 1 (Cg1), prelimbic cortex (PrL), infralimbic cortex (IL), basolateral amygdala (BLA), nucleus accumbens (NAc), and dentate gyrus (DG) were involved in the morphine-induced CTA, and resulted from the aversive effect of morphine on conditioning and reinstatement. The c-Fos data showed fewer neural substrates (e.g., PrL, IL, and LH) on extinction to be hyperactive. In the context of previous drug addiction data, the evidence suggests that morphine injections may induce hyperactivity in many neural substrates, which mediate reward and/or aversion due to disturbance and nonhomeostasis in the brain. The results support the paradoxical effect hypothesis of abused drugs. Insight from the findings could be used in the clinical treatment of drug addiction.

MK-801 prevents the development of behavioral sensitization during repeated morphine administration

Synapse ◽  
1994 ◽  
Vol 16 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Michael Jeziorski ◽  
Francis J. White ◽  
Marina E. Wolf
Keyword(s):  
Behavioral Sensitization ◽  
Mk 801 ◽  
Morphine Administration

scholarly journals Sini-San Regulates the NO-cGMP-PKG Pathway in the Spinal Dorsal Horn in a Modified Rat Model of Functional Dyspepsia

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Zhenyu Wu ◽  
Xiaofang Lu ◽  
Shengsheng Zhang ◽  
Chunyang Zhu
Keyword(s):  
Gene Expression ◽  
Dorsal Horn ◽  
Functional Dyspepsia ◽  
Rat Model ◽  
Spinal Dorsal Horn ◽  
Visceral Hypersensitivity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Gastric Distention ◽  
Real Time Quantitative Pcr ◽  
Spinal Dorsal

The present study investigated the effect of Chinese medicine Sini-San (SNS) on visceral hypersensitivity in a rat model of functional dyspepsia (FD), and it explored related underlying mechanisms. The rat model of FD was developed by combining neonatal iodoacetamide (IA) treatment and adult tail-clamping. After SNS treatment, the behavior and electromyographic testing were performed to evaluate the visceromotor responses of rats to gastric distention. Immunofluorescence was used to detect the distribution of iNOS-positive cells in the spinal dorsal horn, while the real-time quantitative PCR and western blot were used for detection of the gene expression of c-fos, iNOS, and GABAb and protein levels of iNOS and GABAb in the spinal dorsal horn, respectively. The protein concentration of cGMP and PKG proteins in the spinal dorsal horn were quantified by enzyme-linked immunosorbent assay. In this study, SNS treatment significantly reduced the behavioral score and electromyographic response to graded intragastric distension pressure. The middle-dose of SNS treatment significantly reduced the distribution of iNOS-positive cells in the spinal dorsal horn of FD model rats. The gene expression of c-fos, iNOS, and GABAb and the protein contents of iNOS, GABAb, cGMP, and PKG in the spinal dorsal horn of FD model rats were restored to a normal level by middle-dose of SNS treatment. Our results suggest that Sini-San may alleviate the visceral hypersensitivity in FD model rats via regulation of the NO/cGMP/PKG pathway in the spinal dorsal horn.

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