Dec. 23, 2009 Nearly 10 years after the discovery that birds
make a hormone that suppresses reproduction, University of
California, Berkeley, neuroscientists have established that
humans make it too, opening the door to development of a new
class of contraceptive and possible treatments for cancer or
other diseases. The hormone, gonadotropin inhibitory hormone
(GnIH), has the opposite effect from gonadotropin releasing
hormone, a key reproductive hormone. While GnRH triggers a
cascade of hormones that prime the body for sex and procreation,
GnIH puts a brake on the cascade. "Identifying the inhibitory
hormone in humans forces us to revise our understanding of the
control mechanism of human reproduction," said first author
Takayoshi Ubuka, a post-doctoral fellow in the UC Berkeley
Department of Integrative Biology and in the Helen Wills
Neuroscience Institute. "We hope this will stimulate clinical
studies on people with precocious puberty or in the area of
contraception." Because reproductive hormones often pr