Quantitative mRNA analysis of muscarinic acetylcholine receptors in the intestine of dairy cows with spontaneous caecal dilatation–dislocation

Muscarinic receptors mediate acetylcholine-induced muscular contractions. In this study, mRNA levels of muscarinic receptor subtypes 2 and 3 (M2 and M3) in the ileum, caecum, proximal loop of the ascending colon (PLAC) and external loop of the spiral colon (ELSC) were determined by quantitative polymerase chain reaction in seven cows with caecal dilatation–dislocation (CDD) and seven healthy control cows. Levels of M2 were significantly lower in the caecum, PLAC and ELSC and levels of M3 were significantly lower in the ileum, caecum, PLAC and ELSC of cows with CDD compared to healthy cows (P < 0.05). Down-regulation of M3 may play a role in the pathogenesis of CDD.