Tenacious work by researchers from Haifa's Technion University has once again borne fruit. A recent study at the institution has found that continuous use of the hormone melatonin could affect the quality of sperm. With the increase in usage of melatonin during treatments for sleep disorders, researchers at the institute's Sleep Research lab warn of possible damage caused by prolonged treatment using melatonin in adolescents and young men.
Melatonin is a hormone excreted from the pineal gland in the brain. This hormone affects the ?biological clock? in the brain that regulates sleep; an increase in its level enables individuals to make a smooth transition from wake to sleep. Melatonin provides signals to the biological clock about the environmental surrounding lighting: during light hours its secretion is withheld, during hours of darkness its levels rise.
Melatonin is widely used to regulate sleep in people whose biological clock is not synchronized with their surroundings (such as travelers with jet lag or blind people who have no perception of light).
In animals, melatonin marks the changing of the seasons: in the winter its high level depresses the reproductive system. Towards the spring the melatonin level in the blood drops, as mating season begins.
Until today, melatonin has not been found to affect human reproductive organs. Based on their earlier findings that men who suffer from pathological sexual underdevelopment have high levels of melatonin in their blood, the research team, headed by Professor Rafi Luboshitzki of HaEmek Medical Center in Afula and Technion?s Faculty of Medicine, examined the effect of melatonin on the sperm quality of young healthy men. They were prescribed three miligrams of melatonin for three months and the quality of their sperms was compared to when they took placebo for the same period of time. The sperm of some of the men was compromised in concentration and motion only when they took melatonin. This led the researchers to conclude that extended usage of melatonin may lead to a decrease in sperm quality, supposedly due to a local effect of melatonin on testicles.
Research findings were presented recently at the fifth annual symposium of the Israeli Sleep Research Society, conducted at the Technion Faculty of Medicine; they will also be discussed at the fifth European Symposium of Endocrinology, to be held in Italy in June.
Melatonin is a hormone excreted from the pineal gland in the brain. This hormone affects the ?biological clock? in the brain that regulates sleep; an increase in its level enables individuals to make a smooth transition from wake to sleep. Melatonin provides signals to the biological clock about the environmental surrounding lighting: during light hours its secretion is withheld, during hours of darkness its levels rise.
Melatonin is widely used to regulate sleep in people whose biological clock is not synchronized with their surroundings (such as travelers with jet lag or blind people who have no perception of light).
In animals, melatonin marks the changing of the seasons: in the winter its high level depresses the reproductive system. Towards the spring the melatonin level in the blood drops, as mating season begins.
Until today, melatonin has not been found to affect human reproductive organs. Based on their earlier findings that men who suffer from pathological sexual underdevelopment have high levels of melatonin in their blood, the research team, headed by Professor Rafi Luboshitzki of HaEmek Medical Center in Afula and Technion?s Faculty of Medicine, examined the effect of melatonin on the sperm quality of young healthy men. They were prescribed three miligrams of melatonin for three months and the quality of their sperms was compared to when they took placebo for the same period of time. The sperm of some of the men was compromised in concentration and motion only when they took melatonin. This led the researchers to conclude that extended usage of melatonin may lead to a decrease in sperm quality, supposedly due to a local effect of melatonin on testicles.
Research findings were presented recently at the fifth annual symposium of the Israeli Sleep Research Society, conducted at the Technion Faculty of Medicine; they will also be discussed at the fifth European Symposium of Endocrinology, to be held in Italy in June.