Fig. 1.
Body weight and length and food intake of Br-M3-KO mice and control littermates. (A) Lack of M3 mAChRs in brains from Br-M3-KO mice. M3 mAChR densities in mouse brain and salivary glands (submandibular gland) were determined by using a combined radioligand binding/immunoprecipitation approach. For these studies, 4-month-old male mice (littermates) of the indicated genotypes were used. Quinuclidinyl [3H]benzilate-labeled M3 receptors were solubilized from membrane preparations and immunoprecipitated with an M3 receptor-specific antiserum (17). Each bar represents the mean ± SEM of at least 3 independent experiments. (B) Growth curves of Br-M3-KO mice and their control littermates (males). Starting from postnatal week 4, Br-M3-KO mice weighed significantly less than their control littermates (10–12 mice per group). (C) Physical appearance of a representative Br-M3-KO and control (fl/fl) mouse (20-week-old males). (D) Body length (distance from the tip of the nose to the base of the tail) of Br-M3-KO and control littermates (24-week-old males; control, n = 29; Br-M3-KO, n = 10). (E) Food intake studies (16-week-old males; control, n = 18; Br-M3-KO, n = 6). All measurements were carried out with 20-week-old males (control, n = 17; Br-M3-KO, n = 6). In D and E, the 3 control strains (+/+, +/+ NesCre, and fl/fl) gave results that did not differ significantly from each other. The data obtained with these mice were therefore pooled for the sake of clarity. Data are given as means ± SEM. *, P < 0.05; **, P < 0.01, as compared with the corresponding control group(s).