benzofurans and Fetal-Growth-Retardation

The actions of angiotensin II on type 1 (AT₁) and type 2 (AT₂) receptor subtypes are important for normal kidney development before birth. This study investigated the effect of AT₁ receptor antagonism on renal growth and growth regulators in fetal sheep during late gestation. From 125 days of gestation (term 145±2 days), chronically catheterised sheep fetuses were infused intravenously for 5 days with either an AT₁-specific receptor antagonist (GR138950, 2-4 mg/kg per day, n=5) or saline (0.9% NaCl, n=5). Blockade of the AT₁ receptor decreased arterial blood oxygenation and pH and increased blood pCO₂, haemoglobin and lactate, and plasma cortisol and IGF-II. Blood glucose and plasma thyroid hormones and IGF-I were unchanged between the treatment groups. On the 5th day of infusion, the kidneys of the GR-treated fetuses were lighter than those of the control fetuses, both in absolute and relative terms, and were smaller in transverse cross-sectional width and cortical thickness. In the GR-infused fetuses, renal AT₂ receptor protein concentration and glomerular density were significantly greater than in the saline-infused fetuses. Blockade of the AT₁ receptor had no effect on relative cortical thickness, fractional or mean glomerular volumes, or renal protein levels of the AT₁ receptor, IGF type 1 receptor, insulin receptor or protein kinase C ζ. Therefore, in the ovine fetus, AT₁ receptor antagonism causes increased renal protein expression of the AT₂ receptor subtype, which, combined with inhibition of AT₁ receptor activity, may be partly responsible for growth retardation of the developing kidney.

Topics: Angiotensin II Type 1 Receptor Blockers; Animals; Arteries; Benzofurans; Body Weight; Fetal Development; Fetal Growth Retardation; Fetus; Gestational Age; Hormones; Infusions, Intravenous; Kidney; Organ Size; Osmolar Concentration; Oxygen; Proteins; Receptor, Angiotensin, Type 2; Sheep

The purpose of this study was to assess the hypothesized association between persistent organochlorine compounds through the consumption of fatty fish from the Baltic Sea (at the Swedish east coast) and low birthweight.. During the period 1973-1991, 72 cases of low birthweight (1500-2750 g) were selected from among infants born to fishermen's wives within a cohort from the Swedish east coast. For each case two referents were selected. The mothers were interviewed about their dietary and smoking habits and place of living during childhood and adolescence.. A high total current intake of fish from the Baltic Sea (> or = 4 meals per month) tended to increase the risk of having an infant with low birthweight [adjusted odds ratio (OR) 1.9, 95% confidence interval (95% CI) 0.9-3.9]. The effect was more conspicuous for the boys (OR 3.4, 95% CI 1.1-11). No such effects were observed when the estimated intake of fish was considered for the period in which the infant was born. However, mothers who had grown up in a fishing village had an increased risk of having an infant with low birthweight (OR 2.1, 95% CI 1.0-4.3).. The variable "grown up in a fishing village" can be interpreted as an indirect measure of a mother's accumulated consumption of fish from the Baltic Sea. This idea supports an association between a high consumption of contaminated fish from the Baltic Sea and an increased risk for low birthweight. The effect estimates based on the mothers' reported fish consumptions were dependent on the period under consideration and therefore were somewhat ambiguous.

Topics: Adult; Animals; Benzofurans; DDT; Dibenzofurans, Polychlorinated; Diet Records; Feeding Behavior; Female; Fetal Growth Retardation; Fishes; Food Contamination; Humans; Infant, Low Birth Weight; Infant, Newborn; Polychlorinated Biphenyls; Pregnancy; Risk Factors; Sweden; Water Pollutants, Chemical