東大發現鼠涙腺分泌物可催情

Recently the Yomiuri News reported the following:

　東原和成・東京大教授（応用生命化学）らは、オスのマウスの涙腺から分泌される物質が、メスの脳を刺激して交尾を促進することを明らかにした。哺乳(ほにゅう)類の性フェロモンの機構が明らかになったのは初めて。英科学誌ネイチャーに発表した。
　研究チームは、成熟したオスだけが分泌する「ＥＳＰ１」という小さなたんぱく質の機能を解析。メスは通常、オスが交尾を仕掛けても１０回に１回ほどしか受け入れないが、ＥＳＰ１を与えると２回に１回ほどに増えた。 メスは鼻の下部の「鋤鼻(じょび)器官」にあるセンサーでＥＳＰ１を認識し、発情を調整する視床下部に情報を送っていた。センサーを働かなくすると交尾の促進は見られなくなった。 効果てきめんのＥＳＰ１だが、霊長類や人間にはこの遺伝子がなく、男が泣いても効果は期待できない。

Tokyo University professor (applied life chemistry) Higashiharawana and others had clarified that the material secreted from lachrymal gland of male mouse could stimulate mesu of the brain and promote copulation. It was the first time that the mechanism of this sexual pheromone was clarified. It was announced in the British science magazine Nature.

The research team analyzed the function of a small protein "ESP1" that only a mature male would secrete. Even if the male began copulating, in normal condition the mesu of the brain would give only one success out of every ten times, but it was increased to about once every two times wen ESP1 was given. The mesu allowed the sensor that existed in "jobi organ" under the nose to recognize ESP1, and to send information to the hypothalamus that controlled sexual excitement. Without this senor, promotion of copulation could not be seen. But even if a man cried, the effect could not be expected because neither primates nor men had this gene though ESP1 had such an effect.

So, Japanese scientists have proved that the lachrymal grand of the mouse is important for copulating.