Low Birth Weight Disturbs the Intestinal Redox Status and Mitochondrial Morphology and Functions in Newborn Piglets

Abstract

Low birth-weight (LBW) neonates exhibit a lower growth rate and impaired intestinal development. However, the reasons for abnormal development of small intestine in LBW piglets have not been widely studied. The present study focused on the redox status and mitochondrial morphology and functions of the small intestine in LBW newborn piglets. Ten newborn normal birth-weight (NBW) piglets and LBW piglets from 10 primiparous sows with the same parturition day were selected and sampled immediately without sucking colostrum. The small intestine tissues were collected and measured. Compared with NBW newborn piglets, LBW newborn piglets had a significantly decreased length and weight of the small intestine (p < 0.05) as well as the villus height/crypt depth (V/C) index in the jejunum (p < 0.05). Furthermore, LBW piglets had a lower gene expression of tight junction protein zonula occluden-1 (ZO1), claudin 1, antioxidant enzyme catalase (CAT), glutathione peroxidase (GPX) and heme oxygenase-1 (HO-1) in jejunum (p < 0.05). Meanwhile, LBW induced mitochondrial vacuolation and significantly decreased the mRNA expression of PPARγ coactivator-1α (PGC-1α) (p < 0.05) and tended to decrease the expression of cytochrome coxidase IV (Ccox IV) (p = 0.07) and cytochrome C (Cytc) (p = 0.08). In conclusion, LBW newborn piglets showed an abnormal development of the small intestine and disturbed redox status, and this may be caused by impaired morphology and the functions of mitochondria in the jejunum.

Keywords: jejunum; low birth weight; mitochondria; piglets; redox status.

Figure 1

Effects of LBW on mRNA expression of claudin 1, occludin and ZO1 in the jejunum. Data are means ± SEM (n = 10 for each group). the bars (*) indicate statistical significance (p < 0.05) of gene expression between the two groups. NBW, normal birth weight; LBW, low birth weight; ZO1, zonula occluden-1.

Figure 2

Transmission electron micrographs of the effects of LBW on the histomorphology of jejunal mitochondria. NBW, normal birth weight. LBW, low birth weight. Width of photomicrograph field is 500 nm.