Endocrine Abstracts

IntroductionHuman clinical trials are currently evaluating the protective effects of antioxidants against pre-eclampsia in threatened pregnancy (Poston et al. Ann.N.Y.Acad.Sci. 1031:242.2004). While there has been increased awareness about the modulating effects on pituitary-adrenal responses to stress by antioxidants in adult life (Brody et al. Psychopharmacology. 159:319.2001). nothing is known about the effects of antioxida...

Type I 5'-monodeiodinase (5'-MDI) converts thyroxine (T4) to triiodothyronine (T3). In fetal sheep, hepatic 5'-MDI activity increases near term in association with the prepartum cortisol surge. This study investigated the effect of maternal dexamethasone treatment, in clinically relevant doses, on hepatic and renal type I 5'-MDI activity and plasma thyroid hormone concentrations in fetal sheep.From 125 days of gestation (term 145 pl...

Introduction: Increased plasma AVP contributes to the peripheral vasoconstrictor response to acute hypoxaemia in the fetus (Giussani et al. J.Physiol. 477, 81, 1994). We have shown that fetal pre-exposure to umbilical cord compression (UCC) sufficient to restrict fetal blood supply by 30%, markedly blunts the subsequent fetal vasoconstrictor response to hypoxaemia (Gardner et al. Circulation 106: 2278, 2002). This study determined whether this blunting is due to an effect on f...

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In the adult, females release more ACTH and adrenal steroids than males in response to stress, and these differences have been attributed to the stimulatory and inhibitory effects on the HPA axis of oestrogens and androgens, respectively (see Rivier, Pharm. Biochem. Behav. 64(4):739-751, 1999). The effects of sex differences on pituitary-adrenal responses to stress during fetal life remain unknown. This study compared the plasma ACTH and cortisol responses to acute hypoxia in ...

The fetus may successfully respond to acute hypoxaemia, but little is known about what effects prevailing adverse intrauterine conditions might have on these responses. The fetal cardiovascular response to acute hypoxaemia involves increased plasma vasopressin, which aids the redistribution of blood flow away from the periphery towards the fetal brain (Perez et al. Am.J.Physiol. 256:1011-1018, 1989). We investigated the effects of prevailing, but independently-occurring, hypox...

Introduction: Umbilical cord occlusion (UO) sufficient to restrict fetal blood supply by 30 percent results in a range of fetal endocrine adaptations including increased fetal plasma cortisol. The extent to which this may promote premature maturation of fetal organs and tissues is not known. This study aimed to determine if UO results in premature maturation of mitochondria within fetal adipose tissue.Methods: Nine ewes were entered into the study, which...