Desenvolvimento físico, sexual e fisiologia reprodutiva da prole feminina de ratas diabéticas

OBJECTIVES: The objective of this study was to evaluate physical and sexual development and reproductive physiology in female rat offspring that developed in hyperglycemia conditions in utero and during lactation. MATERIALS AND METHODS: Maternal diabetes was induced in female rats by a single IV injection of streptozotocin before mating. Female offspring development was evaluated by means of the following parameters: physical development; age of vaginal opening and first estrus; weight and histological evaluation of uterus and ovaries; duration of the estrous cycle, sexual behavior, and fertility after natural mating. RESULTS: In the female offspring, maternal diabetes caused delays in initial physical development; diminution in ovary weight and number of follicles; and inferior reproductive performance compared with the control group. CONCLUSIONS: The exposure to hyperglycemia in uterus and during lactation caused delays in physical and sexual development, and affected the reproductive physiology of female rats negatively560296103FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP04/12948-0; 04/15664-2OBJETIVOS: O objetivo deste estudo foi avaliar o desenvolvimento físico e sexual e a fisiologia reprodutiva de ratas que se desenvolveram em condições hiperglicêmicas in utero e lactação. MATERIAIS E METODOS: Para induzir o diabetes nas ratas, foi utilizada estreptozotocina em dose única via intravenosa antes do acasalamento. A prole feminina foi avaliada por meio dos seguintes parâmetros: o desenvolvimento físico; a idade de abertura vaginal e do primeiro estro, peso e avaliação histológica do útero e ovários; a duração do ciclo estral, o comportamento sexual e a fertilidade após acasalamentos naturais. RESULTADOS: O diabetes materno provocou, na prole feminina, retardo no desenvolvimento físico; diminuição do peso dos ovários e do número de folículos; a performance reprodutiva foi inferior à do grupo controle. CONCLUSÕES: Concluiu-se que a exposição aos meios intrauterino e lactacional hiperglicêmicos provocou retardo no desenvolvimento físico e sexual e prejudicou a fisiologia reprodutiva de ratasFundunesp, Proc. 01089/0

Neonatally induced mild diabetes: influence on development, behavior and reproductive function of female Wistar rats

Abstract\ud \ud \ud \ud Background\ud Neonatal STZ treatment induces a state of mild hyperglycemia in adult rats that disrupts metabolism and maternal/fetal interactions. The aim of this study was investigate the effect of neonatal STZ treatment on the physical development, behavior, and reproductive function of female Wistar rats from infancy to adulthood.\ud \ud \ud \ud Methods\ud At birth, litters were assigned either to a Control (subcutaneous (s.c.) citrate buffer, n = 10) or STZ group, (streptozotocin (STZ) - 100 mg/kg-sc, n = 6). Blood glucose levels were measured on postnatal days (PND) 35, 84 and 120. In Experiment 1 body weight, length and the appearance of developmental milestones such as eye and vaginal opening were monitored. To assess the relative contribution of the initial and long term effects of STZ treatment this group was subdivided based on blood glucose levels recorded on PND 120: STZ hyperglycemic (between 120 and 300 mg/dl) and STZ normoglycemic (under 120 mg/dl). Behavioral activity was assessed in an open field on PND 21 and 75. In Experiment 2 estrous cyclicity, sexual behavior and circulating gonadotropin, ovarian steroid, and insulin levels were compared between control and STZ-hyperglycemic rats. In all measures the litter was the experimental unit. Parametric data were analyzed using one-way or, where appropriate, two-way ANOVA and significant effects were investigated using Tukey’s post hoc test. Fisher’s exact test was employed when data did not satisfy the assumption of normality e.g. presence of urine and fecal boli on the open field between groups. Statistical significance was set at p < 0.05 for all data.\ud \ud \ud \ud Results\ud As expected neonatal STZ treatment caused hyperglycemia and hypoinsulinemia in adulthood. STZ-treated pups also showed a temporary reduction in growth rate that probably reflected the early loss of circulating insulin. Hyperglycemic rats also exhibited a reduction in locomotor and exploratory behavior in the open field. Mild hyperglycemia did not impair gonadotropin levels or estrous cylicity but ovarian steroid concentrations were altered.\ud \ud \ud \ud Conclusions\ud In female Wistar rats, neonatal STZ treatment impairs growth in infancy and results in mild hyperglycemia/hypoinsulinemia in adulthood that is associated with changes in the response to a novel environment and altered ovarian steroid hormone levels.The authors are thankful to Ruither Carolino for hormonal determinations, to Felipe Hiroshi Saito and Silvia Sakamoto for technical assistance, to Fernanda Pereira Lima for her help with animal care, and to CAPES for financial support

The Coadministration of N-Acetylcysteine Ameliorates the Effects of Arsenic Trioxide on the Male Mouse Genital System

Arsenic trioxide (As2O3) has shown effectiveness in treatment of leukemia but is also associated with reproductive toxicity. Since remediation with N-acetylcysteine (NAC) may mitigate the adverse effects caused by exposure, we assessed the effects of As2O3 and its potential reversibility after exposure cessation or coadministration of NAC. Animals received 0.3 or 3.0 mg/Kg/day of As2O3 subcutaneously and 40 mM of NAC in tap water. As2O3 treatment impaired spermatogenesis and sperm motility and decreased seminal vesicle weight and testosterone serum levels; after suspension of treatment, these parameters remained altered. When NAC was administered, animals showed improvement in sperm parameters and seminal vesicle weight. In vitro epididymal contractility was increased in As2O3-treated animals. We concluded that As2O3 is toxic to the male mouse genital system by compromising sperm quality and quantity; these effects persisted even after suspension of the treatment. However, the coadministration of NAC ameliorates the harmful effects of the drug on the male genital system

Interpreting histopathology in the epididymis

While most of this Special Issue is devoted to the testis (which is where most drug and chemically induced toxicity of the male reproductive tract is identified), being able to recognize and understand the potential effects of toxicants on the epididymis is immensely important and an area that is often overlooked. The epididymis is the organ where the post-testicular sperm differentiation occurs, through a complex and still not completely understood sperm maturation process, allowing them to fertilize the oocyte. Also in the epididymis, sperm are stored until ejaculation, while being protected from immunogenic reaction by a blood-epididymis barrier. From a toxicologic perspective the epididymis is inherently complicated as its structure and function can be altered both indirectly and directly. In this review we will discuss the factors that must be considered when attempting to distinguish between indirect and direct epididymal toxicity and highlight what is currently known about mechanisms of epididymal toxicants, using the rat as a reference model. We identify 2 distinguishable signature lesions - one representing androgen deprivation (secondary to Leydig cell toxicity in the testis) and another representing a direct acting toxicant. Other commonly observed alterations will also be shown and discussed. Finally, we point out that many of the key functions of the epididymis can be altered in the absence of a detectable change in tissue structure. Collectively, we hope this will provide pathologists with increased confidence in identification of epididymal toxicity and enable more informed guidance as mechanism of action is considered

I Workshop on Male Reproductive Biology

Proceedings of the I Workshop on Male Reproductive Biology carried out in Brazil, from November 05 to 07, 2007

Toxicology of Metals and Metalloids

Metal toxicology is one of the oldest areas of study of toxicology and one of the oldest environmental problems. Metals and metalloids are toxic elements at the top of the priority list of hazardous substances of the Agency for Toxic Substances and Disease Registry (ATSDR). However, several gaps of knowledge still exist that are related to their toxicity, mainly concerning the mechanisms of action. This special issue affords the opportunity to bring together the results of nine papers covering several aspects of the toxicology of metals and metalloids in in vitro and in vivo experimental models, as well as in exposed populations