Figure 9.

RT-PCR detection of mRNA expression of muscarinic M₁ and M₃ acetylcholine receptor subunits in isolated rat colonic crypts. The agarose gel shows bands of cDNA fragments amplified using specific primers for M₁ (373 bp) and M₃ receptors (434 bp). cDNA from spinal cord was used as positive control. The efficiency of RNA isolation and cDNA synthesis was verified by using GAPDH-specific primers (303 bp). Representative results from three independent experiments. Cry, colonic crypts; SC, spinal cord; RT-PCR, reverse transcription polymerase chain reaction; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.