Rats exposed to protein restriction as fetuses develop hypertension as adults. Hypertension increases the risk of myocardial ischaemia and infarction. We investigated whether rats exposed to low-protein diets in utero are more susceptible to myocardial ischaemia -reperfusion (IR) injury. Pregnant Wistar rats were fed control or low-protein (MLP) diets throughout pregnancy. At 4 and 8 weeks postnatal age systolic blood pressure was determined in the offspring using tail-cuff plethysmography. At 6 months of age, rats were treated with saline or N-acetylcysteine (NAC) for 48 h. Rapidly excised hearts were retro-perfused (Langendorff) to assess isolated cardiac function before (baseline), during 30 min ischaemia (no coronary perfusion) and for 60 min after reinstating coronary perfusion (reperfusion). Hearts were then harvested and treated appropriately for analysis of infarct size. Exposure to the MLP diet in utero significantly increased systolic blood pressure at 4 and 8 weeks of age (6-13 mmHg increase; P,0·001) and significantly impaired recovery of left ventricular developed pressure after ischaemia at 6 months of age in male offspring only (P,0·003). Pre-treatment with NAC prevented this impairment of recovery in MLP male offspring and improved recovery in all females. Myocardial infarct size was not different between dietary groups after IR, but NAC pre-treatment significantly reduced the degree of infarction (P, 0·001). In conclusion, an MLP diet throughout gestation significantly impairs recovery of the 6-month-old adult rat heart to IRinduced injury in a sex-specific manner. Undernutrition during development may increase susceptibility to CHD by impairing recovery from coronary events.

The present study examined the extent to which the late gestation rise in fetal plasma cortisol influenced adipose tissue development in the fetus. The effect of cortisol on the abundance of adipose tissue mitochondrial proteins on both the inner (i.e. uncoupling protein (UCP)1) and outer (i.e. voltage-dependent anion channel (VDAC)) mitochondrial membrane, together with the long and short forms of the prolactin receptor (PRLR) protein and leptin mRNA was determined. Perirenal adipose tissue was sampled from ovine fetuses to which (i) cortisol (2-3 mg/ day for 5 days) or saline was infused up to 127-130 days of gestation, and (ii) adrenalectomised and intact controls at between 142 and 145 days of gestation (term=148 days). UCP1 protein abundance was significantly lower in adrenalectomised fetuses compared with age-matched controls, and UCP1 was increased by cortisol infusion and with gestational age. Adrenalectomy reduced the concentration of the long form of PRLR, although this effect was only significant for the highest molecular weight isoform. In contrast, neither the short form of PRLR, VDAC protein abundance or leptin mRNA expression was significantly affected by gestational age or cortisol status. Fetal plasma triiodothyronine concentrations were increased by cortisol and with gestational age, an affect abolished by adrenalectomy. When all treatment groups were combined, both plasma cortisol and triiodothyronine concentrations were positively correlated with UCP1 protein abundance. In conclusion, an intact adrenal is necessary for the late gestation rise in UCP1 protein abundance but cortisol does not appear to have a major stimulatory role in promoting leptin expression in fetal adipose tissue. It remains to be established whether effects on UCP1 protein are directly regulated by cortisol alone or mediated by other anabolic fetal hormones such as triiodothyronine.

Modelling maternal obesity in rats adversely affected steroid synthesis, uterine contractile associated protein expression and ex-vivo uterine contractility during labour. This maternal obesity model can be utilized further to unravel the mechanisms causing uterine dystocia in obese women.

The Western diet is typically high in salt and fructose, which have pressor activity. Maternal diet can affect offspring blood pressure, but the extent to which maternal intake of excess salt and fructose may influence cardiovascular function of the offspring is unknown. We sought to determine the effect of moderate maternal dietary intake of salt and/or fructose on resting and stimulated cardiovascular function of the adult male and female offspring. Pregnant rats were fed purified diets (±4 % salt) and water (±10 % fructose) before and during gestation and through lactation. Male and female offspring were weaned onto standard laboratory chow. From 9 to 14 weeks of age, cardiovascular parameters (basal, circadian and stimulated) were assessed continuously by radiotelemetry. Maternal salt intake rendered opposite-sex siblings with a 25-mmHg difference in blood pressure as adults; male offspring were hypertensive (15 mmHg mean arterial pressure (MAP)) and female offspring were hypotensive (10 mmHg MAP) above and below controls, respectively. Sex differences were unrelated to endothelial nitric oxide activity in vivo, but isolation-induced anxiety revealed a significantly steeper coupling between blood pressure and heart rate in salt-exposed male offspring but not in female offspring. MAP of all offspring was refractory to salt loading but sensitive to subsequent dietary fructose, an effect exacerbated in female offspring from fructose-fed dams. Circadian analyses of pressure in all offspring revealed higher mean set-point for heart rate and relative non-dipping of nocturnal pressure. In conclusion, increased salt and fructose in the maternal diet has lasting effects on offspring cardiovascular function that is sex-dependent and related to the offspring's stress-response axis.Key words: Rats: Hypertension: Fructose: Salt: Maternal nutrition: Stress Ancestral man is predicted to have eaten a diet high in fibre, K, complex carbohydrates and protein and low in Na, refined sugars and energy density. Typically, a palaeolithic diet provided a plant-to-animal energy ratio of 1:1, with the net acid-load being alkaline (1,2) . Analyses of the diets of modern hunter-gatherer populations support these predictions (2,3) . Since this time, when physiological and metabolic systems were evolving, there has been a gradual transition away from this palaeolithic diet. With the emergence of agriculture (about 7-5000 years ago) through to the industrial revolution (about last 100 years), the 'modern diet' has rapidly become low in fibre and high in Na, simple sugars and energy density (4) . When superimposed on the palaeolithic genotype and physiology, the modern diet has resulted in an increased incidence of non-communicable diseases (NCD), which is estimated to account for 60 % of all deaths worldwide (5) . The economic impact of NCD is vast: $558, $237 and $33 billion in China, India and the UK, respectively (6) , whereas $750 billion is spent annually in the USA for diabetes and hypertension alone (7) . Modification of di...

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Advanced maternal age of first time pregnant mothers is associated with prolonged and dysfunctional labor and significant risk of emergency cesarean section. We investigated the influence of maternal age on myometrial contractility, expression of contractile associated proteins (CAPs), and global gene expression in the parturient uterus. Female Wistar rats either 8 (YOUNG n = 10) or 24 (OLDER n = 10) weeks old were fed laboratory chow, mated, and killed during parturition. Myometrial strips were dissected to determine contractile activity, cholesterol (CHOL) and triglycerides (TAG) content, protein expression of connexin-43 (GJA1), prostaglandin-endoperoxide synthase 2 (PTGS2), and caveolin 1 (CAV-1). Maternal plasma concentrations of prostaglandins PGE2, PGF2α, and progesterone were determined by RIA. Global gene expression in uterine samples was compared using Affymetrix Genechip Gene 2.0 ST arrays and Ingenuity Pathway analysis (IPA). Spontaneous contractility in myometrium exhibited by YOUNG rats was threefold greater than OLDER animals (P < 0.027) but maternal age had no significant effect on myometrial CAP expression, lipid profiles, or pregnancy-related hormones. OLDER myometrium increased contractile activity in response to PGF2α, phenylephrine, and carbachol, a response absent in YOUNG rats (all P < 0.002). Microarray analysis identified that maternal age affected expression of genes related to immune and inflammatory responses, lipid transport and metabolism, steroid metabolism, tissue remodeling, and smooth muscle contraction. In conclusion YOUNG laboring rat myometrium seems primed to contract maximally, whereas activity is blunted in OLDER animals and requires stimulation to meet contractile potential. Further work investigating maternal age effects on myometrial function is required with focus on lipid metabolism and inflammatory pathways.

BackgroundIncreased consumption of linoleic acid (LA, omega-6) in Western diets coupled with the pro-inflammatory and adipogenic properties of its derivatives has led to suggestions that fetal exposure to this dietary pattern could be contributing to the intergenerational cycle of obesity.MethodThis study aimed to evaluate the effects of maternal consumption of a LA to alpha-linolenic acid (ALA) ratio similar to modern Western diets (9:1) compared to a lower ratio (1:1.5) on placental and fetal growth, and to determine any cumulative effects by feeding both diets at two total fat levels (18% vs 36% fat w/w). Female Wistar rats (n = 5–7/group) were assigned to one of the four experimental diets prior to mating until 20d of gestation.ResultsFatty acid profiles of maternal and fetal blood and placental tissue at 20d gestation were different between dietary groups, and largely reflected dietary fatty acid composition. Female fetuses were heavier (2.98 ± 0.06 g vs 3.36 ± 0.07 g, P < 0.01) and male placental weight was increased (0.51 ± 0.02 g vs 0.58 ± 0.02 g, P < 0.05) in the low LA:ALA groups. Female fetuses of dams exposed to a 36% fat diet had a reduced relative liver weight irrespective of LA:ALA ratio (7.61 ± 0.22% vs 6.93 ± 0.19%, P < 0.05). These effects occurred in the absence of any effect of the dietary treatments on maternal bodyweight, fat deposition or expression of key lipogenic genes in maternal and fetal liver or maternal adipose tissue.ConclusionThese findings suggest that both the total fat content as well as the LA:ALA ratio of the maternal diet have sex-specific implications for the growth of the developing fetus.

Increasing levels of obesity within women of reproductive age is a major concern in the UK. Approximately, 13% of women aged !30 and 22% of 31-to 40-year-old women are obese. Obesity increases complications during pregnancy and the risk of caesarean section due to prolonged labour and poor uterine activity. The aim was to investigate whether a high-fat, high-cholesterol (HFHC) diet decreases markers of uterine contractility during parturition in the rat. Female Wistar rats were fed control (CON, nZ10) or HFHC (nZ10) diets for 6 weeks. Animals were mated and, once pregnant, maintained on their diet throughout gestation. On gestational day 19, rats were monitored continuously and killed at the onset of parturition. Body and fat depot weights were recorded. Myometrial tissue was analysed for cholesterol (CHOL), triglycerides (TAG), and expression of the contractile associated proteins gap junction protein alpha 1 (GJA1; also known as connexin-43, CX-43), prostaglandin-endoperoxide synthase 2 (PTGS2; also known as cyclo-oxygenase-2, COX-2) and caveolin-1 (CAV1) and maternal plasma for prostaglandin F 2a (PGF 2a ) and progesterone. HFHC fed rats gained greater weight than CON (P!0.003) with significant increases in peri-renal fat (P!0.01). The HFHC diet increased plasma CHOL, TAG and progesterone, but decreased PGF 2a versus CON (P!0.01, P!0.01, PZ0.05 and P!0.02 respectively). Total CHOL and TAG levels of uterine tissue were similar. However, HFHC fed rats showed significant increases in PTGS2 (P!0.037), but decreases in GJA1 and CAV1 (PZ0.059). In conclusion, a HFHC diet significantly increases body weight and alters lipid profiles that correlate with decreases in key markers of uterine contractility. Further work is required to ascertain whether these changes have adverse effects on uterine activity.