Fig. 1.
Intraperitoneal peptide YY (PYY) and PYY3–36 inhibit fecal pellet output (FPO) response to novelty environmental stress for 1 h in mice. A: novelty increased defecation in naive mice (n = 16) exposed singly to a novel environment (box) compared with trained mice (n = 16) accustomed singly to the box for 1 h/day for 3–4 days prior. B: dose-response of PYY3–36 on novelty stress-induced defecation. PYY3–36 was injected intraperitoneally 10 min before the stress (n = 7–8/group). C: effect of intraperitoneal injection of neuropeptide Y (NPY)/PYY agonists with different Y receptor selectivity on novelty stress-induced defecation. Peptides (8.0 nmol/kg ip) or saline were injected 10 min before the stress. FPO was monitored every 15 min for 1 h. Data are means ± SE of n = 7–13/group. *P < 0.05 vs. saline at the corresponding time.