PMC

Sex did not affect wet tissues, wet pool size, DM, and NDF contents of reticulorumen (RR), and the ratio between DM intake and reticulorumen wet pool size (DM intake:RR wet pool size ratio) (P ≥ 0.07). Females and intact males presented similar reticulorumen digesta mean retention time (MRT) of solutes (MRT_Cr)”. (5.6 h; P = 0.92) and they presented greater reticulorumen MRT_Cr than castrated males (7.0; P ≤ 0.04). The ratio between DM intake and reticulorumen wet tissues (DM intake:RR wet tissues ratio) was greater for males than females (P ≤ 0.04), and it was similar between males (P = 0.95). Body weight quadratically affected reticulorumen wet tissues and wet pool size (P < 0.01). Body weight linearly affected reticulorumen MRT_Cr and the DM intake:RR wet tissues ratio (P ≤ 0.05). Body weight did not affect reticulorumen MRT_iNDF and the DM intake:RR wet pool size ratio (P ≥ 0.11). The symbol ○ and dashed line represent castrated males, ⁎ and dotted line represent females, □ and solid line represent intact males, + and dash-dotted line represent females and intact males mean, ♦ and dash-short-dashed line represent males mean, and ▲ and solid line represent all sexes mean.

(A) Clutch size (number of juveniles being brooded); (B) wet weight of entire brood (g); (C) mean (+SD) juvenile wet weight (mg); and (D) within-brood CV of mean juvenile weight.

A: liver wet weight. B: liver wet weight normalized to bodyweight. C: heart wet weight. D: heart wet weight normalized to bodyweight. E: brain wet weight. F: brain wet weight normalized to bodyweight. n = 8–9 mice per group. A Student’s t test was used for statistical analysis. *Statistical significance at α set at P < 0.05. Values are means ± SD.

Morphine-induced suppression of defecation in conscious mice was reversed by lubiprostone. Mice were injected with morphine (3 mg/kg), and after 30 min they received a second injection of either 2.6% DMSO or 0.2 mg/kg lubiprostone. All injections were subcutaneous. Fecal pellets were collected counted and weighed at 30- or 60-min intervals over a time period of 6 h. A, 1, lubiprostone treatment (●) significantly elevated (P < 0.001) the cumulative number of fecal pellets compared with controls (○; 2.6% DMSO). Morphine (□) suppressed fecal pellet output compared with controls (P < 0.001). Morphine effects started to return toward control levels 120 min after morphine treatment. Injection of lubiprostone (■) 30 min after administration of morphine did not reverse the action of morphine on fecal output. The data represent the sum total number of fecal pellets accumulated at the end of each test period. For example, if three pellets had appeared at the end of the first 30 min and four pellets during the next 15 min, and then the data point on the graph at 45 min was entered as seven pellets (3 + 4 = 7). 2, quantitative data for the action of lubiprostone (Lubi.) on morphine suppression of fecal output after 180 min. B, 1, lubiprostone treatment (●) significantly elevated (P < 0.001) the cumulative wet weight of fecal pellets compared with 2.6% DMSO (○). Morphine (□) suppressed fecal pellet wet weight compared with controls (P < 0.001). Morphine effects started to return toward control levels 120 min after morphine treatment. Injection of lubiprostone (■) 30 min after administration of morphine restored fecal wet weight to control levels within an hour of injection. 2, quantitative data for the action of lubiprostone (Lubi.) on morphine-induced suppression of fecal wet weight in the time interval between lubiprostone injection and suppression of fecal wet weight 120 min after injection of morphine. C, 1 and 2, wet weights of single fecal pellets varied between 2.8 and 103 g. Because wet weight of each fecal pellet was greatly elevated for lubiprostone-treated animals, we normalized fecal pellet weight to pellet number and expressed the data as weight per pellet. Lubiprostone treatment (●) significantly elevated (P < 0.001) the cumulative wet weight of individual fecal pellets relative to 2.6% DMSO (○). Morphine (□) suppressed wet weight per pellet compared with DMSO controls (P < 0.001). Morphine effects started to return toward control levels approximately 120 min after morphine treatment. Injection of lubiprostone (■) 30 min after administration of morphine rapidly reversed the effect of morphine on weight per pellet. 2, quantitative data for the action of lubiprostone (Lubi.) on morphine suppression of weight per pellet in the time interval between lubiprostone injection and suppression of fecal wet weight 120 min after injection of morphine. Values are expressed as means ± S.E.M., with n = 8–38 mice (**, ♦♦, P < 0.001). Two-way analysis of variance with Bonferroni post hoc analysis.