1,721,056 research outputs found
Endocannabinoid System in Health and Disease: Current Situation and Future Perspectives.
No full text
Microplastics: A threat for male fertility
No full textMuch of the planet is swimming in discarded plastic, which is harming animal and possibly human health. Once at sea, sunlight, wind, and wave action break down plastic waste into small particles: the microplastics (MPs). Currently, particular attention has been drawn to their effects on aquatic environments but the health risks, especially in mammals, are poorly known. These non‐biodegradable materials can act as a vector for environmental pollutants, can be ingested by humans in food and water, and can enter and accumulate in human tissues with a possible risk for heath. Recent studies revealed the deleterious effects of MPs exposure in male reproduction and sperm quality, making them a potential hazard to reproductive success. This manuscript summarizes the main changes in sperm quality along the lifespan and the upcoming studies on the effects of MPs in male fertility in mammals
EDCs: Focus on reproductive alterations in mammalian and nonmammalian models
No full textIt is well known that endocrine-disrupting chemicals, thanks to their ability to mimic or antagonize sexual hormone activity, can affect the reproductive functions of both wild animals and humans. Some of them are slow to break down in the environment, making them potentially hazardous over time. Starting in 2000, experts concluded there was credible evidence that very low doses of some hormone-like chemicals can adversely affect bodily functions in test animals. Many studies so far evaluated the endocrine properties of a plethora of chemicals, and in this chapter, attention will be mainly posed to Bisphenol A, its analogs, most common phthalates, and components of flame retardants. All these compounds affect body reproductive tissues in mammalian and nonmammalian species by interacting with the hypothalamic–pituitary–gonadal axis. Results presented within the chapter will help to create a comprehensive database from several scientific studies on how different substances interact with natural hormones and their receptors, thus contrasting or potentiating their physiological effects
Kisspeptin receptor,GPR54, as a candidate for theregulation of testicular activity in the frog, Rana esculenta.
No full textKisspeptins, acting via GPR54, are new players in the control
of reproductive axis. They have the ability to communicate with
GnRH neurons sending environmental, metabolic, and gonadal
signals, with the induction of GnRH and LH secretion as final
effect. At present, the physiological significance of kisspeptin
signaling in the gonad is poorly investigated. We cloned GPR54
receptor from the anuran amphibian Rana esculenta testis and
investigated its expression in several tissues (brain, spinal cord,
ovary, muscle, and kidney). In particular, the expression analysis
was carried out in pituitary and testis during the annual sexual
cycle. Pituitary and testicular GPR54 mRNA increased at the end
of the winter stasis (February) and reached high levels during the
breeding season (April). The analysis of GPR54 expression in
testis was reinforced by in situ hybridization that revealed
GPR54 presence in the interstitial compartment and in
proliferating germ cells. Testicular GPR54 expression in February
and in June was indicated to be estradiol dependent.
Furthermore, in February, kisspeptin-10 (Kp-10) induced the
testicular expression of both GPR54 and estrogen receptor alpha
(ERalpha) in a dose-dependent manner. Conversely, in March,
Kp-10 had a biphasic effect on the expression of ERalpha, being
inhibitory at short (1 h) and stimulatory at longer (4 h)
incubation time. In conclusion, our results demonstrate that
frog testis expresses GPR54 in an estradiol-dependent manner
and that Kp-10 modulates the testicular expression of ERalpha;
thus, the kisspeptin/GPR54 system might be locally involved in
the regulation of estrogen-dependent testicular functions such as
germ cell proliferation and steroidogenesis
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