Androstenedione synergizes with stress or prenatal drug exposure to retard fetal growth: role of IGF

Evolution of Yolk Androgens in Birds: Development, Coloniality, and Sexual Dichromatism

Current theory recognizes the adaptive value of maternal effects in shaping offspring phenotypes in response to selective pressures and vindicates the value of these traits in fostering adaptation and speciation. Yolk androgens in birds are a relatively well-known maternal effect and have been linked to adaptations related to development, coloniality life, and sexual selection. We tested whether interspecific patterns of yolk androgen levels (androstenedione and testosterone) were related to interspecific variation in development, sexual selection, and coloniality. First, we found no relationship between androgen levels and duration of development as reflected by incubation and nestling periods. However, androstenedione concentration was positively related to the relative duration of the incubation period and negatively related to the relative duration of the nestling period. These relationships were confirmed by analyses of phylogenetically independent contrasts. We suggest that androstenedione concentration may have evolved as a mechanism to shift the relative duration of development between the egg and nestling stages in response to selective pressures that differentially affect the duration of each stage. Second, neither plumage dichromatism nor mating system explained significant variation in yolk androgen levels after correction for similarity among species due to common descent. This finding indicates that sexual selection has not been an important selective pressure for this maternal effect. Third, we found a highly significant positive relationship between degree of breeding coloniality and concentration of androstenedione but not testosterone. These effects were confirmed in analyses of contrasts controlling for similarity due to common descent. Since the relationship with coloniality was different for each androgen, it is unlikely that increased levels of androgens in highly colonial species are a mere consequence of elevated androgen levels in mothers. Rather, our results suggest that high levels of androstenedione in eggs of colonial species are an adaptation to colony life, possibly related to the production of highly competitive phenotypes. In conclusion, from a comparative perspective, the results of this study support the role of maternal effects in promoting adaptation to certain environmental pressures.

Effects of oral androstenedione on steroid metabolism in liver of pregnant and non-pregnant female rats

It is unknown whether androstenedione, a steroidal dietary supplement taken to enhance athletic performance, can affect physiological hormone levels by altering liver enzyme activities that metabolize steroid hormones. Altered hormone levels could be especially devastating during pregnancy. Mature female rats were gavaged with 0, 5, 30 or 60 mg/kg/day androstenedione beginning two weeks prior to mating and continuing through gestation day 19. Non-pregnant female rats were gavaged over the same time frame with 0 or 60 mg/kg/day androstenedione. Livers were removed from dams on gestation day 20 and from non-pregnant rats after five weeks' treatment. Liver microsomes were incubated with 200 microM testosterone, and the reaction products were isolated and analyzed by HPLC. In pregnant rats, formation of 6alpha-, 15beta-, 7alpha-, 16beta-, and 2beta-hydroxytestosterone was increased significantly vs. control at the highest dose level only. Formation of 6beta-hydroxytestosterone increased significantly at both the 30 and 60 mg/kg/day dose levels. In non-pregnant rats, 60 mg/kg/day androstenedione significantly increased formation of 15beta-, 6beta-, 16beta-, and 2beta-hydroxytestosterone. The data suggest that high oral doses of androstenedione can induce some female rat liver cytochromes P450 that metabolize steroid hormones and that the response to androstenedione does not differ between pregnant and non-pregnant female rats.

Anesthesia and acoustic stress-induced intra-uterine growth retardation in mice

Stress interferes with reproduction, adversely influencing implantation and fetal growth, and sometimes even leading to abortion. Here, we attempted to evaluate the early gestational effects of uncomfortable sound on pregnant mice and their offspring. Ten-week-old pregnant Jcl:ICR mice were exposed to sound (100 dB, random frequency between 9-34 kHz) for 8 hours on the 3(rd), 5(th) and 7(th) gestational days (GD). The effects of general anesthesia were also investigated, with or without acoustic stress. All groups were examined on the 18(th) GD for fetal growth. Fetal weight, number of ossified sacrococcygeal vertebrae and placental weight were all significantly reduced (P<0.0001) when stress was induced on the 7(th) GD, but not on the 3(rd) or 5(th) GD. This intra-uterine growth retardation (IUGR) was significantly inhibited by general anesthesia (P<0.0001), although general anesthesia alone induced significant IUGR (P<0.0001) when compared with control mice. This suggests that acoustic exposure indirectly exerts an effect on fetal growth, possibly via a psycho-maternal pathway. We also found that analysis of the number of ossified sacrococcygeal vertebrae is the most sensitive tool for the study of IUGR.

Birth to age 7 growth of children prenatally exposed to drugs: a prospective cohort study

Prenatal exposure to cocaine, alcohol, and cigarettes has been linked to decreased birth weight and length. Unclear, however, is whether growth deficits persist into childhood. Women who were pregnant, African-American, not HIV-positive, and who delivered singleton infants were extensively screened throughout pregnancy for cocaine, alcohol, cigarette, and other illicit drug use. Of the approximately 1100 eligible subjects, 665 families were located at a 7-year postbirth follow-up and 540 participated. After appropriate control for potential confounders and prenatal exposures, prenatal exposure to cocaine, alcohol, and cigarettes each independently predicted birth weight and length. At age 7, prenatal cocaine exposure was significantly related to height deficits after accounting for other prenatal exposures and significant confounders. Children at age 7 exposed to cocaine in utero were up to 1 in. shorter and twice as likely to fall below the 10th percentile in height as the control children after accounting for other significant confounders including other prenatal exposures. Maternal age moderated the relation between prenatal exposures and child growth. Children born to women over 30 and exposed to cocaine were up to 2 in. shorter and four times more likely to have clinically significant height deficits at age 7. Children of older women and exposed to moderate-to-high levels of alcohol prenatally were up to 14 lb lighter and five times more likely to fall below the 10th percentile in weight. Similar growth restriction was not associated with prenatal exposures for children born to younger mothers. These outcomes add to the growing body of literature detailing long-term effects of prenatal drug exposure, suggesting differential effects for cocaine and alcohol, and indicating that maternal age may moderate these effects. Mechanisms for growth restriction and failure of catch-up under conditions of prenatal exposures are presented, suggesting further study of these developmental outcomes.

Yolk androgens reduce offspring survival

Females may favour some offspring over others by differential deposition of yolk hormones. In American kestrels (Falco sparverius), we found that yolks of eggs laid late in the sequence of a clutch had more testosterone (T) and androstenedione (A4) than yolks of first-laid eggs. To investigate the effects of these yolk androgens on nestling 'fitness', we injected both T and A4 into the yolks of first-laid eggs and compared their hatching time, nestling growth and nestling survival with those of first-laid eggs in which we injected vehicle as a control. Compared to controls, injection of T and A4 at a dose intended to increase their levels to those of later-laid eggs delayed hatching and reduced nestling growth and survival rates. Yolk androgen treatment of egg 1 had no effect on survival of siblings hatching from subsequently laid eggs. The adverse actions of yolk androgen treatment in the kestrel are in contrast to the favourable actions of yolk T treatment found previously in canaries (Serinus canaria). Additional studies are necessary in order to determine whether the deposition of yolk androgens is an adaptive form of parental favouritism or an adverse by-product of endocrine processes during egg formation. Despite its adaptive significance, such 'transgenerational' effects of steroid hormones may have helped to evolutionarily shape the hormonal mechanisms regulating reproduction.

Cocaine in pregnancy. Recent data on maternal and fetal risks

Cocaine continues to be abused during pregnancy, creating increased demands on the health care system. Epidemiology and basic science research have identified and confirmed risks of adverse maternal and fetal effects when cocaine is used during pregnancy. These effects of cocaine in pregnant women often are influenced by a number of confounding variables. This article reviews those cocaine effects as well as recent data, which examine in greater detail the risks of adverse outcomes of prenatal cocaine exposure during pregnancy.