Persistent hexavalent chromium exposure impaired the pubertal development and ovarian histoarchitecture in wistar rat offspring.

Hexavalent chromium (CrVI) is a highly toxic metal and a major environmental pollutant. Several studies indicate that CrVI exposure adversely affects reproductive function. We reported that maternal Cr exposure resulted in Cr accumulation in the reproductive organs of female offsprings.

Ameliorative effect of vitamin C on hexavalent chromium-induced delay in sexual maturation and oxidative stress in developing Wistar rat ovary and uterus.

Hexavalent chromium (CrVI) is a highly toxic metal and major environmental pollutant and is extensively used in more than 50 industries. The major route of CrVI exposure for the general population is oral intake. Chromium is considered an important nutrient responsible for carbohydrate metabolism.

Is gender difference in postnatal thyroid growth associated with specific expression patterns of androgen and estrogen receptors?

Variations in sex steroids bioavailability were linked to the gender difference in the growth of thyroid glands of neonatal rats. In the present study we tested androgen receptor (AR) and estrogen receptor (ER) concentrations by ligand binding assay, and expression of their genes by RT-PCR and Western blot in the thyroid glands of neonatal rats. AR concentration remained elevated from postnatal day (PND) 10 onwards in males, whereas it decreased by PND 20 in females.

Mechanism underlying transient gestational-onset hypothyroidism-induced impairment of posttesticular sperm maturation in adult rats.

Objective: To understand the mechanism underlying gestational-onset hypothyroidism-induced male infertility.

Design: Controlled laboratory study.

Setting: Research laboratory in a university department of endocrinology.

Lactational hexavalent chromium exposure-induced oxidative stress in rat uterus is associated with delayed puberty and impaired gonadotropin levels.

Hexavalent chromium (CrVI) is a transition element utilized in many fields of modern industries. CrVI is a reproductive metal toxicant that can traverse the placental barrier and cause a wide range of fetal effects. Therefore, the present study was carried out to determine the CrVI-induced utero-toxicity.

Gestational and neonatal-onset hypothyroidism alters androgen receptor status in rat prostate glands at adulthood.

Background: Infertility associated with congenital and early childhood hypothyroidism is an important reproductive health problem in men. Nevertheless, the exact mechanism underlying hypothyroidism-induced changes in the prostate gland, an androgen-dependent organ that contributes a significant portion of the seminal plasma remains obscure. The present study tested the hypothesis "transient gestational- or neonatal-onset hypothyroidism may have duration dependent and lobe specific effect on androgen receptor (AR) status in the prostate glands of adult rats.

Lactational exposure to hexavalent chromium delays puberty by impairing ovarian development, steroidogenesis and pituitary hormone synthesis in developing Wistar rats.

Hexavalent chromium (Cr-VI) is used in a wide range of industries. Cr-VI from chromate industries and atmospheric emissions contribute to the Cr contamination in the environment. Cr is a reproductive metal toxicant that can traverse the placental barrier and cause a wide range of fetal effects including ovotoxicity.

Testosterone and estradiol up-regulate androgen and estrogen receptors in immature and adult rat thyroid glands in vivo.

Thyroid gland is one of the non-classical target organs for sex steroids. Presence of androgen and estrogen receptors in the neoplastic and non-neoplastic thyroid glands of mammalian species is well documented. The aim of the present study is to elucidate the changes in serum and thyroidal sex steroids, and their receptors in the thyroid gland of rats from immature to adult age under gonadectomized (GDX) and sex steroids replaced conditions.

Testosterone and estradiol differentially regulate TSH-induced thyrocyte proliferation in immature and adult rats.

Though sex steroids are found to influence thyroid pathogenesis in human and in animals, their role in normal thyroid growth and thyrocyte proliferation is not yet understood fully. The present study is addressed to know the effect of testosterone and estradiol on the basal and TSH-induced thyrocyte proliferation in immature and adult rats in vitro. The male and female Wistar rats were gonadectomized (GDX) and one group of GDX rats were supplemented with either testosterone or estradiol.

Developmental profiles of TSH, sex steroids, and their receptors in the thyroid and their relevance to thyroid growth in immature rats.

Sex steroids are reported to influence thyroid pathogenesis in human and experimental animals. However, there is no report on this phenomenon during the early developmental period. The mitotic activity of thyrocytes in rats reaches its peak by day 10 postpartum.