Effects of Transmaternal Exposure to Genistein in Hatano High- and Low-Avoidance Rats

Abstract

Abstract:Hatano high-and low-avoidance (HAA and LAA) rats are separated by breeding from Sprague-Dawley rats by high versus low rates of avoidance responses in a shuttle-box task. In addition, compared to HAA rats, LAA rats show lower running-wheel activity, later sexual maturation, 5-day estrous cycling, lower sperm motility, more pronounced immunological reactions, and are generally less reactive to stress. The present study was designed to compare the effects of transmaternal exposure to genistein on these characteristics between HAA and LAA rats. To this aim, litters from both strains were fostered onto Sprague-Dawley rats receiving genistein by gavage with 5 mg/animal/day from day 17 of pregnancy through day 21 of lactation. Inhibited growth after weaning and reduced uterine weight at weaning were observed in the LAA offspring reared by genistein-treated dams. IgM antibody production in response to sheep red blood cells was significantly decreased in the HAA offspring reared by genistein-treated dams. During restraint stress, the plasma concentration of corticosterone was significantly lower in the LAA offspring reared by genistein-treated dams. Strain-related differences were detected in shuttle-box avoidance performance, running-wheel activity, estrous cycling, and sperm motility. The results demonstrate that transmaternal exposure to genistein potentially affects the immunological and stress responses as well as the postweaning growth of the offspring. It suggests that a comparative study using Hatano rats would be useful for studying the influence of endocrine active chemicals on the whole body systems.

Epigenetics: prenatal exposure to genistein leaves a permanent signature on the hematopoietic lineage

“…These changes were caused by hypermethylation of transposable repetitive elements [intracisternal A particles (IAPs)] upstream of the transcription start site of the Agouti gene (3). Other studies have shown that transplacental exposure of rats to genistein exerts long-lasting effects on the endocrine and immune systems and altered stress response and postweaning growth (4,5). In a recent article, Möller et al (6) demonstrated that genistein exposure during development induces long-term effects on the uterine gene expression profile.…”

Hatano rats are a suitable metabolic syndrome model for studying feeding behavior, blood pressure levels, and percent body fat

“…A previous study showed that under normal conditions, HAA rats secrete lesser CRH from the PVN, which suppresses appetite, than LAA rats [1]. Moreover, previous studies have shown that HAA rats are more active than LAA rats [12, 20]. Active locomotion is associated with higher food consumption, suggesting that more active rodents require higher energy intake.…”

Hatano rats selectively bred for high- and low-avoidance learning: an overview

“…Because the HAA and LAA lines have well characterized endocrine and immune systems, the effects of an endocrine active compound were examined using these strains. Neonates from both lines were fostered by Sprague Dawley rats receiving genistein by gavage from day 17 of pregnancy through day 21 of lactation [36]. Genistein is a typical phytoestrogen that exhibits estrogenic activity in a rodent uterotrophic assay [38].…”