Koichi Hamano

A method of sex identification using the polymerase chain reaction technique is described. Using a pair of nucleotide primers from an X-Y homologous region, both the X and the Y sequences can be amplified simultaneously, and more importantly, they result in fragments of different lengths. The success of the procedure is therefore monitored by the presence of a X-specific band while sex is identified by the presence or absence of a Y-specific band.

Relaxin is a peptide hormone found in seminal plasma that has a physiological influence on sperm motility in some species. There are no reports on the effect of relaxin on acrosome reaction and utilization of glucose in boar spermatozoa. In this study, to investigate the effects of relaxin on sperm motility, acrosome reaction, and incorporation and oxidation of labeled glucose, boar spermatozoa were washed and preincubated for swim-up and then incubated (0-6 h) with 0, 20, or 40 ng/ml relaxin in mTALP medium. The results indicated that the addition of relaxin stimulated sperm motility significantly (P<0.05) during 1-4 h of incubation. The percentage of acrosome-reacted live spermatozoa was higher (P<0.05) when the spermatozoa were treated with 20 or 40 ng/ml relaxin. The rate of incorporation, and oxidation of glucose were also greater (P<0.05) in the spermatozoa incubated with relaxin compared to the control spermatozoa. The rate of incorporation and oxidation of (14)C-glucose were increased in correlation with acrosome reaction up to 4 h of incubation and then decreased in line with the increasing incubation period. In conclusion, the present study demonstrates that relaxin accelerates not only motility but also the acrosome reaction and utilization of glucose in boar spermatozoa.

Porcine relaxin is a peptide hormone belonging to the insulin super family that has a variety of biological functions. The present experiment was designed to investigate the effects of relaxin on sperm function and on in vitro fertilization (IVF) of porcine oocytes. Porcine spermatozoa were washed, swum-up, and incubated for 1-4 h in mTALP medium supplemented with 0, 20 or 50 ng/ml porcine relaxin. Motility was determined by observing the type of forward movement of the spermatozoa, and acrosome status was evaluated by applying the triple staining technique. Immature oocytes were aspirated from antral follicles and matured in IVM medium (modified NCSU-37). Matured oocytes were co-cultured with spermatozoa in IVF medium (mTALP) supplemented with 0, 5, 10, 15 or 20 ng/ml relaxin. After 6 h of sperm-oocyte co-incubation, putative zygotes were cultured for 18 h in oocyte culture medium NCSU-37 and then assessed for the rates of monospermy, polyspermy, and male pronucleus formation after acetic orcein staining. Relaxin improved (P<0.05) sperm motility and increased the percentage of acrosome-reacted live spermatozoa during 1-4 h of incubation, although viability was not significantly improved. Significantly (P<0.05) the highest percentage of monospermic (31.7%) and lowest percentage of polyspermic (16.5%) fertilization was achieved from the sperm-oocyte co-culture group treated with 20 ng/ml relaxin as compared to other groups. The percentage of male pronucleus formation was significantly (P<0.05) greater in the 20 ng/ml relaxin-treated sperm-oocyte co-culture group than in the other groups. These results indicate that supplementation with relaxin is capable of improving sperm function and fertilization of porcine oocytes in vitro.

Aim: Relaxin and insulin‐like growth factor (IGF)‐I have pronounced effects on the male and female reproductive tracts. The aim of this study was to investigate the effects of relaxin and IGF‐I on the motility, capacitation, acrosome reaction, cholesterol efflux and utilization of glucose in porcine spermatozoa. Methods: Swim‐up separated spermatozoa that had been washed twice were incubated at 37°C for 1 or 4 h in modified Tyrode's albumin lactate pyruvate (mTALP) medium supplemented without (control) or with relaxin (20 ng/mL) or IGF‐I (20 ng/mL) or both (10 + 10 ng/mL). Results: Progressive motility and the induction rate of capacitation and acrosome reaction were increased ( P &lt; 0.05) by relaxin and IGF‐I alone or in combination, especially after 4 h of incubation. Relaxin alone or combined with IGF‐I enhanced ( P &lt; 0.05) the cholesterol efflux after 4 h, whereas IGF‐I alone did not show any significant effect on the cholesterol efflux compared with the control at any time point. The utilization rates of labeled and unlabeled glucose increased ( P &lt; 0.05) in spermatozoa incubated with relaxin or IGF‐I alone or in combination compared with the control. Conclusion: Thus, supplementation of relaxin alone or combined with IGF‐I into the medium possibly plays a beneficial role in porcine spermatozoal prefertilization events in vitro . (Reprod Med Biol 2008; 7 : 29–36)

BACKGROUND: Functional constipation (FC), a functional bowel disorder with symptoms of constipation, has considerable impact on quality of life. As data regarding its prevalence and epidemiology are lacking, this study aimed to evaluate the prevalence, population composition, lifestyle, quality of life, and clinical characteristics of these individuals by comparing people with and without FC. These parameters were also compared among individuals with strong and weak awareness of constipation. METHODS: An internet survey was conducted among 10,000 individuals aged 20-69 years from the general Japanese population; they were registered with an internet survey company. The following data were obtained: age, sex, educational history, occupation, residence, history of other diseases, lifestyle (including smoking/drinking habits using the Japanese Health Practice Index, medication use, symptoms of constipation according to the Rome III criteria, stool types according to the Bristol stool scale, and use of laxatives, including the place of purchase and cost per month or acceptable cost per month. The 8-item Short Form Health Survey Questionnaire was also used; FC was diagnosed based on Rome III criteria. All respondents were classified according to their awareness of constipation (i.e. strong or weak), and their characteristic features were compared. RESULTS: The data of 3000 respondents were evaluated; 262 (8.7%) had FC, which was common among older adults, women, and homemakers. FC was associated with changes in the frequency of bowel movement, sensation of incomplete or scanty evacuation, and the use of manual maneuvers; these are consequential clinical symptoms of FC. These individuals frequently skipped breakfast, had insufficient sleep, had more severe constipation, and had purchased laxatives in pharmacies or online more often than those without FC. A strong awareness of constipation was significantly more prevalent among women and homemakers. A history of anemia and cardiovascular disease was significantly more frequent in the strong awareness group, whereas a history of hypertension was more frequent in the weak awareness group. CONCLUSIONS: Appropriate and comprehensive management should be provided for FC, based on the understanding of its characteristic features and considering the symptoms and lifestyle.