Fig 2: Effect of bethanechol chloride on colorectal contraction. (A) Representative recordings show the effect of bethanechol chloride on colorectal muscle strips from control and 6-OHDA rats. (B) Concentration response curve of bethanechol chloride alone and in the presence of TTX (1 µM) in control rats (n = 6). (C) Dose-response curve of bethanechol chloride in the colorectum of control and 6-OHDA rats (n = 6). (D) Concentration-response curve of bethanechol chloride in M2R and M3R knockout (KO) mice (n = 5). (B–D) Two strips per rat. ***P < 0.001.

Fig 3: Repression of P2rx1 by progressive vascular endothelial damage. (a–c) RQ-PCR (a) and western blot (b,c) analysis of the expressions of the cholinergic receptor muscarinic 2 (Chrm2), cholinergic receptor muscarinic 3 (Chrm3), and purinergic receptor P2X 1 (P2rx1) genes in the bladders of rats in the indicated groups. Expression levels of the indicated transcripts are presented as % Gapdh. For western blot analysis, ß-actin was used as a loading control, and the expression levels of the indicated proteins were normalized to the ß-actin value. (d,e) Representative images (d) and quantification analysis (e) of the immunohistochemical staining for the P2rx1 protein (original magnification ×200, scale bar = 200 µm). All quantification results are presented as mean ± SEM. *p < 0.05, **p < 0.01, and ***p < 0.001, compared to the sham group; ###p < 0.05, ###p < 0.01, ###p < 0.001, compared with the AI-30 group according to the unpaired t-test (c) or one-way analysis of variance with the Bonferroni post hoc test. (a–e) Source data with exact p-values and number of replicates can be found in the Supplementary Dataset.