Peripheral mechanisms of intestinal dysmotility in the morphine tolerant and dependent rats

• Autorzy: Banach T. , Zurowski D. , Gil K. , Weisbrodt N.W. , Rosenfeld G. , Thor P.J.
• Języki publikacji: EN

Abstrakty

EN

Changes of intestinal motility and transit produced by tolerance to and dependence upon morphine have been partly attributed to peripheral mechanisms. We evaluated the effect of chronic peripheral morphine administration and peripheral µ-receptor blockade on vagal afferent activity (VAA) and c-Kit positive intramuscular cells of Cajal (ICCs). Ten rats were subjected to chronic subcutaneous morphine infusion for 72 h with subsequent VAA recording. Potential frequency was evaluated within recordings before and after µ receptor blockade by D-Phe -Cys -Tyr -D-Trp -Orn -Thr -Phe -Thr (CTOP) i.p. injections. Afterwards the rats were sacrificed and intramuscular c-Kit antigen expression was assessed by image analysis within removed fragments of duodenum and ascending colon. An equal group of rats served as a control for VAA and c-Kit expression. Analysis of VAA revealed similar frequencies of potentials in morphine tolerant / dependent rats before CTOP and in the controls. CTOP increased potential frequency in the morphine group which effect was visible mostly within the first 20 minutes (p=0.01). The morphine infused animals presented also higher c-Kit expression in both the duodenum (p<0.001) and the ascending colon (p<0.001) in comparison to the control group. Results of our study may indicate the involment of both the intestinal wall and the long vago-vagal reflexes in tolerance to and dependence upon opioids.

Słowa kluczowe

EN

vagus afferent activity; morphine tolerance; chronic pain; intestinal motility; rat; peripheral mechanism; intestinal dysmotility

• Wydawca: -
• Czasopismo: Journal of Physiology and Pharmacology
• Rocznik: 2006
• Tom: 57
• Numer: 1
• Opis fizyczny: p.73-82,fig.,ref.

Twórcy

autor

Banach T.

• Jagiellonia University Medical College, Czysta 18, 31-543 Krakow, Poland

autor

Zurowski D.

autor

Gil K.

autor

Weisbrodt N.W.

autor

Rosenfeld G.

autor

Thor P.J.