口服精胺激发血浆皮质醇促进哺乳仔猪肠道发育的机理

Mechanism of orally administered spermine releasing blood cortisol on the intestinal development in suckling piglets

试验建立仔猪血浆皮质醇抑制模型初步探索精胺促进哺乳仔猪肠道发育的机制。选取6窝11日龄的哺乳仔猪进行试验,采用随机区组设计,以窝别为区组,每头仔猪为试验重复,每窝选取体重相近的4头仔猪(共24头)随机分配到4个处理组。处理组设计如下:处理组1,口服生理盐水和注射生理盐水;处理组2,口服0.4 mmol/(kg BW·d)精胺和注射生理盐水;处理组3,口服生理盐水和肌肉注射5 mg/(kg BW·d)甲双吡丙酮(metyrapone);处理组4,注射5 mg/(kg BW·d)甲双吡丙酮和口服0.4 mmol/(kg BW·d)精胺。结果显示:试验成功地建立血浆皮质醇模型。处理组1~4仔猪空肠黏膜麦芽糖酶比活力分别为118.5、195.3、88.3、144.2 U/g蛋白。处理组2麦芽糖酶比活力显著高于处理组1和处理组4(P<0.05),且显著高于处理组3(P<0.05);处理组1和处理组4麦芽糖酶比活力差异不显著,但显著高于处理组3(P<0.05)。处理组1和处理组3空肠绒毛高度差异不显著(P>0.05),且显著高于处理组2和处理组4(P<0.05)。以上结果初步证明,口服精胺具有激发血浆皮质醇促进幼龄哺乳仔猪肠道发育的作用。

The blood cortisol inhibition model was established for primary studies of orally administered spermine on the intestinal development in suckling piglets. For three consecutive days, 24 suck-ling piglets at 11 days of age were randomly assigned within litter to one of four groups with six animals each and received following treatments, group 1(orally administered physiological saline and intramuscular injection of physiological saline), group 2 [orally administered 0.4 mmol/(kg BW · d)spermine and intramuscular injection of physiological saline], group 3 [orally administered physiologi-cal saline and intramuscular injection of 5 mg/(kg BW·d) metyrapone], or group 4 [orally administered0.4 mmol/(kg BW·d) spermine and received the intramuscular injection of 5 mg/(kg BW·d) metyra-pone]. The data of plasma cortisol concentration showed that the cortisol inhibition model was successful in this study. The jejunum maltase specific ac-tivities of pigs were 118.5, 195.3, 88.3, 144.2 U/g(mucosa protein). The maltase specific activitiesof group 1 and 4 were identical, and were higherthan that of group 3(P<0.05), and were lowerthan that of group 2(P<0.05). The villus heightin jejunum of group 1 and 3 were identical, andwere higher than those of group 2 and group 4(P<0.05). Collectively, the results show that orally administered spermine induces young piglet intesti-nal maturation by the blood cortisol release.