Analgesia and mouse strain influence neuromuscular plasticity in inflamed intestine

Abstract

Smooth muscle growth is common to both models of colitis. In contrast, ENS damage in TNBS is correlated with the severe response of a Crohn's disease-like phenotype, while DSS correlates with a milder, ulcerative colitis-like outcome in the deeper tissues. Analgesia with tramadol over buprenorphine is supported for mouse studies of IBD.

Opioid-Induced Immunomodulation: Consequences for the Experimental Coxsackievirus B3-Induced Myocarditis Model

“…Little information exists related to the effect of opioid administration in disease models ( Figure 3 ). In total, 16 studies have been conducted in disease models [ 24 , 25 , 26 , 27 , 32 , 33 , 34 , 35 , 36 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ], including in models of lung cancer, contact hypersensitivity, infection, autoimmune encephalomyelitis, and surgery. In nine of those studies, rats were used [ 25 , 26 , 27 , 36 , 40 , 41 , 43 , 44 , 46 ], which does not allow a transfer of the results into murine models without critical evaluation.…”

“…This is supported by excellent review articles describing an increased number of opportunistic infections after chronic application of opioids [ 28 , 29 ], implying that opioid administration in experimental CVB3-induced myocarditis might lead to worsened disease outcomes accompanied by severe suffering of mice. Increased expression of anti-inflammatory mediators, like IL-4 [ 30 , 31 ] and IL-10 [ 32 , 33 ], reduced clinical score [ 34 ], and less inflammation [ 35 ] have further been reported following opioid administration. Moreover, the substance itself exerts therapeutic effects [ 36 ], which makes it impossible to adequately evaluate new treatment options.…”

A Review of the Effects of Pain and Analgesia on Immune System Function and Inflammation: Relevance for Preclinical Studies

“…26 In BALB/c mice, tramadol administration did not affect inflammation, but buprenorphine was antiinflammatory. 24 BU08070, a buprenorphine analog, produced a concentration-dependent decrease in inflammation and visceral pain-induced behaviors in male BALB/c mice. 229 To keep murine models of UC and CD consistent with human treatments, opioids are generally recommended as therapeutics to decrease model associated discomfort and improve animal welfare.…”

“…53,175,221,222 Pain is an essential feature of IBD and optimal treatment in animals can aid the translation to human medicine, where the challenge of intestinal pain is frequently met with opioids. 24,31 This is because IBD is characterized by periods of remission and reactivation, and NSAID consumption is considered a primary cause of disease reactivation. 57,106 Figure 4 summarizes the effects that analgesics have been reported to have in models of IBD.…”

“…100 The effectiveness of DSS-induced UC depends on several factors, including dosage (typically 1% to 5% DSS), duration (acute or chronic), manufacturer or batch of DSS, strain of animals (C3H/HeJ and BALB/c mice strains are more susceptible), sex of animals (male mice are more susceptible), and microbiota of animals (for example germ free compared with SPF). 24,51,100,126,169 Several NSAID and opioids have been evaluated in both mice and rats in the DSS model for their effects on the inflammatory process. Rofecoxib decreased inflammation in male BABL/c mice, 137 whereas indomethacin and celecoxib both worsened the severity of inflammation in both sexes of Wistar rats.…”