AJRI 2000; 44:193 – 196 Printed in Ireland - all rights resered. Effect of Hepatocyte Growth Factor on Sperm Motility MASAYA KITAMURA, KIYOMI MATSUMIYA, KENZI NISHIMURA, MASAKI YAMANAKA, KUNIO MATSUMOTO, AND AKIHIKO OKUYAMA Kitamura M, Matsumiya K, Nishimura K, Yamanaka M, Matsumoto K, Okuyama A. Effect of hepatocyte growth factor on sperm motility. AJRI 2000; 44:193 – 196 © Munksgaard, Copenhagen PROBLEM: Hepatocyte growth factor (HGF) exists abundantly in seminal plasma and its receptor, c-met, is expressed on spermatozoa. Considering its motogenic activity, we speculated that HGF might affect the movement ability of spermatozoa. METHODS: Recombinant HGF was added to washed spermatozoa and their move- ments were analyzed using a computer-assisted sperm analyzer. The concentration of HGF in the seminal plasma of infertile patients (n =83) was measured by ELISA, and the data were compared with their hormonal profile and semen parameters. RESULTS: The HGF physiological concentration (1 ng/mL) maintained the motility of sperm after a long incubation, though the difference was not statistically significant. Recombinant HGF did not affect the linearity or frequency of movement, which suggested that it does not evoke the hyperactivation of spermatozoa. The concentra- tion of HGF in seminal plasma did not correlate with any clinical parameter of the patients. CONCLUSIONS: These findings contradict the theory that HGF controls the move- ment of sperm. The main role of this axis in the male reproductive system might be maturation in the epididymis. Key words: Hepatocyte growth factor, sperm, sperm motility MASAYA KITAMURA KIYOMI MATSUMIYA KENZI NISHIMURA MASAKI YAMANAKA AKIHIKO OKUYAMA Department of Urology, Osaka University Medical School, Suita, Japan KUNIO MATSUMOTO Division of Biochemistry, Biomedical Research Center, Osaka University Medical School, Suita, Japan Address reprint requests to Masaya Kitamura, Department of Urology (E4), Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565-0871 Japan. E-mail: masaya@uro.med.osaka-u.ac.jp Submitted November 10, 1999; accepted January 30, 2000. INTRODUCTION Hepatocyte growth factor (HGF) was originally cloned and identified as a potent mitogen for mature hepatocytes 1 , but many studies have revealed that it induces a spectrum of biological activities including mitogenic, motogenic and morphogenic activities. In the reproductive system, the importance of HGF in females has already been established. 2 HGF acts to stimulate the growth and migration of trophoblastic cells and its knockout embryos showed disorganized placentas. 3 The exact role of HGF in the ovulatory AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY VOL. 44, 2000