Consumo de água engarrafada de braço dado com a redução da fertilidade masculina
Investigadores elucidam o mecanismo através do qual os disruptores endócrinos comprometem a viabilidade das gâmetas humanas.
Todos nos utilizamos com frequência determinados produtos como pastas de dentes, protectores solares, garrafas de plástico ou brinquedos. No entanto nem todos sabem que eles estão repletos de químicos nocivos para o ser humano. Uma destas classes de químicos são os disruptores endócrinos.
“Neste estudo demonstramos pela primeira vez a relação entre a exposição a disruptores endócrinos presentes em produtos industriais e os efeitos no esperma humano”. Referiu um dos coautores do estudo Niels Skakkebaek.
Os disruptores endócrinos comprometem a fertilidade interferindo com um canal de cálcio presente nas membranas que controla a motilidade do esperma. Eles fazem abrir este canal levando à entrada do cálcio. Isto vai levar à perda de motilidade do esperma levando posteriormente à libertação prematura das enzimas que deveriam destruir as camadas mais exteriores do óvulo. Para além disso são ainda capazes de diminuir a sensibilidade à progesterona e as prostaglandinas, responsáveis por guiar os espermatozóides no órgão feminino.
Common Chemicals Damage Sperm
Researchers elucidate a molecular mechanism through which endocrine disrupting compounds compromise the viability of human gametes.
Additives known as endocrine disrupting chemicals (EDCs) compromise male fertility by interfering with a membrane-bound calcium channel that normally controls motility of sperm cells, according to researchers in Germany and Denmark. EDCs are used in hundreds of household products—including toothpastes, sunscreens, cosmetics, plastic bottles, and toys—and scientists determined that they can cause fertility problems in previous studiesl . But a study published in the journal EMBO reportes (May 12) is the first to posit a mechanism for how the chemical additives affect fertility in the human reproductive tract.
“For the first time, we have shown a direct link between exposure to endocrine disrupting chemicals from industrial products and adverse effects on human sperm function,” study coauthor and Copenhagen University Hospital researcher Niels Skakkebaek said in a statement
Skakkebaek and his colleagues tested 96 EDCs and found that about a third of them disrupted the function of an ion channel, called CatSper, in the membranes of sperm cells in vitro. EDCs, at concentrations typical for bodily fluids, added to human sperm opened CatSper channels, causing calcium to rush into the cells. This increased concentration of calcium ions changed the swimming behavior of the sperm, triggering the premature release of digestive enzymes that sperm need to breach the outer layers of egg cells. EDCs also appeared to decrease sperm’s sensitivity t progesterone and prostaglandins, hormones released by egg cells to guide the swimming cells to their ultimate target. “Compare it with your GPS receiving abnormal signals,” Skakkebaek told CNN “This may result in a wrong destination—read: the sperm may not reach the egg and fertilization may not occur.”
The European Commission is currently reviewing its policies on EDCs. Allan Pacey, a researcher at Sheffield University in the United Kingdom, told the Guardin that the new study is interesting, but should not, in isolation, change the advice that physicians give to their patients regarding EDCs. “Although sperm calcium changes may be seen in the laboratory, this is a long way removed from what might happen in living people,” he said.
http://www.the-scientist.com/?articles.view%2FarticleNo%2F39959%2Ftitle%2FCommon-Chemicals-Damage-Sperm%2F
Investigadores elucidam o mecanismo através do qual os disruptores endócrinos comprometem a viabilidade das gâmetas humanas.
Todos nos utilizamos com frequência determinados produtos como pastas de dentes, protectores solares, garrafas de plástico ou brinquedos. No entanto nem todos sabem que eles estão repletos de químicos nocivos para o ser humano. Uma destas classes de químicos são os disruptores endócrinos.
“Neste estudo demonstramos pela primeira vez a relação entre a exposição a disruptores endócrinos presentes em produtos industriais e os efeitos no esperma humano”. Referiu um dos coautores do estudo Niels Skakkebaek.
Os disruptores endócrinos comprometem a fertilidade interferindo com um canal de cálcio presente nas membranas que controla a motilidade do esperma. Eles fazem abrir este canal levando à entrada do cálcio. Isto vai levar à perda de motilidade do esperma levando posteriormente à libertação prematura das enzimas que deveriam destruir as camadas mais exteriores do óvulo. Para além disso são ainda capazes de diminuir a sensibilidade à progesterona e as prostaglandinas, responsáveis por guiar os espermatozóides no órgão feminino.
Common Chemicals Damage Sperm
Researchers elucidate a molecular mechanism through which endocrine disrupting compounds compromise the viability of human gametes.
Additives known as endocrine disrupting chemicals (EDCs) compromise male fertility by interfering with a membrane-bound calcium channel that normally controls motility of sperm cells, according to researchers in Germany and Denmark. EDCs are used in hundreds of household products—including toothpastes, sunscreens, cosmetics, plastic bottles, and toys—and scientists determined that they can cause fertility problems in previous studiesl . But a study published in the journal EMBO reportes (May 12) is the first to posit a mechanism for how the chemical additives affect fertility in the human reproductive tract.
“For the first time, we have shown a direct link between exposure to endocrine disrupting chemicals from industrial products and adverse effects on human sperm function,” study coauthor and Copenhagen University Hospital researcher Niels Skakkebaek said in a statement
Skakkebaek and his colleagues tested 96 EDCs and found that about a third of them disrupted the function of an ion channel, called CatSper, in the membranes of sperm cells in vitro. EDCs, at concentrations typical for bodily fluids, added to human sperm opened CatSper channels, causing calcium to rush into the cells. This increased concentration of calcium ions changed the swimming behavior of the sperm, triggering the premature release of digestive enzymes that sperm need to breach the outer layers of egg cells. EDCs also appeared to decrease sperm’s sensitivity t progesterone and prostaglandins, hormones released by egg cells to guide the swimming cells to their ultimate target. “Compare it with your GPS receiving abnormal signals,” Skakkebaek told CNN “This may result in a wrong destination—read: the sperm may not reach the egg and fertilization may not occur.”
The European Commission is currently reviewing its policies on EDCs. Allan Pacey, a researcher at Sheffield University in the United Kingdom, told the Guardin that the new study is interesting, but should not, in isolation, change the advice that physicians give to their patients regarding EDCs. “Although sperm calcium changes may be seen in the laboratory, this is a long way removed from what might happen in living people,” he said.
http://www.the-scientist.com/?articles.view%2FarticleNo%2F39959%2Ftitle%2FCommon-Chemicals-Damage-Sperm%2F
Por: Pedro Videira, m6298
Esta descoberta trás à luz o porque de um problema cada vez mais comum a redução da fertilidade. O uso de disruptores endócrinos que estão presentes nas mais variadas coisas no nosso dia a dia tem esta consequência. No entanto na minha opinião acho que não se deve criar um pânico generalizado acerca deste assunto. Este foi apenas um primeiro estudo vamos esperar para ver os próximos e decidir se consumir mesmo água engarrafada reduz a nossa capacidade reprodutiva.
ResponderEliminarPedro Videira, m6298