Endocrine Abstracts

11β hydroxysteroid dehydrogenase (11βHSD) type 2 inactivates cortisol and has not been previously found in ovine or human adipose tissue (1,2). Early-mid nutrient restriction (NR) increases adipose tissue stores in term offspring and upregulates 11βHSD1 mRNA expression in perirenal adipose tissue. We determined the presence of 11βHSD2 mRNA expression in omental adipose tissue of neonatal lambs after early-mid maternal NR.

19 twin-bearing ewes of similar body weight and parity were randomly allocated into control (C) or nutrient restricted (NR) groups at 25 days gestation. NR ewes (n=12) received 50% of their metabolisable energy (ME) requirements from 30-80 days gestation, followed by 100% ME until lambing, while C ewes (n=7) received 100% ME throughout gestation (term=147 days). Lambs delivered spontaneously and one lamb was randomly selected for humane euthanasia at day 7. Omental 11 βHSD2 mRNA expression was determined by RT-PCR utilising specifically designed ovine oligonucleotide primers. The resultant PCR product was sequenced and results cross-referenced against the Genbank website to determine specificity of the target gene. Results are represented as means (plus/minus SEM) and differences analysed by Mann-Whitney U Test.

The omental fat PCR product was shown to be 11βHSD2. Birth weights [C=3.29(0.24), NR=3.19(0.15)Kg], total fat [C=58.9(8.4), NR=65.7(7.2)g], and omental fat [C=11.7(2.7), NR=12.4(1.7)g] were similar between groups. There was no significant difference in 11 βHSD2 abundance between C and NR and groups [C=113.9(29.9), NR=307.9(115.2), p=0.21].

We have shown that 11βHSD2 is expressed in ovine omental adipose tissue and that this expression is not influenced by early-mid maternal NR at day 7 of postnatal life. The presence of omental 11βHSD2 may have a bearing on future adipose tissue deposition and development of obesity.

(1) Whorwood et al. Endocrinology 142: 2854-2864 (2001).

(2) Bujalska et al. Lancet 349: 1210-1213 (1997).

(3) Bishop et al. Endocrinology 144: 3575-3585 (2003).