Development of the small intestine of piglets in response to prenatal elevation of glucocorticoids

Abstract

The effects of prenatal adrenal stimulation and synthetic glucocorticoicl supplementation on developrncnt of the gastro-intestinal tract of the piglet were investigated. Twelve pregnant sows were treated with either ACTH infusion. Isoflupredone injection or Saline between days I05 and 112 of gestation. Neonatal pigs were weighed. bled and sacrificed at 0 or at 6 h. Piglets sacrificed at 6 h were fed bovine colostrum. Trailsvcrse sections were prcpared from the duucienuin. i e j ~ ~ n uman cl ileum for measurcment of thc villus amplification factor (VAF) and basal membrane circunifercnce. Sows in the ACTH group showed an cle\,ation in cortisol in response to infusion: this decreased aftcr infusion and then rose again at parturition. Piglcts from both the ACTH and Saline groups had more villus surface area per unit of body weight (BW) than those born to Isotluprcdone-treated animals. The BW of the ACTH piglets was lowcr (P < 0.05) than those of piglets in the other groups. Whcn the weight of thc stomach and the Small Intestine (SI) was cxpressetl as a function of thc body weight, tlic stomach and S1:BW ratio was larger (p < 0.05) in pigs born to ACTH-treated sows. The circumfcrence of the ilcurn was larger at 6 h than at 0 h. Control pigs had a higher concentration of bovine IgG at 4 and 6 h (P < 0.05). Observations of thc light microscvpic preparations indicated a less organized epithelium in both ACTH and isotluprcdone pigs sacrificed at O Ii. Light and EM preparations of ileum from ACTH pigs sacrificed at 6 h. showcd an abundance of dark-stained vacuoles. characteristic of IgG-containing structures. These became lcss evident in piglets from the Isotlupredone group and even less so in thc control groups. The consequences of these phenomena in terms of absorptive capacity are discusscd.