A study was conducted to investigate the effects of the beta-2 receptor agonist, clenbuterol, on the slow-twitch soleus (SOL) and the fast-twitch extensor digitorum longus (EDL) muscles. Twelve male 5-wk-old mice (ddY ) were divided into two groups ; control ( CANT, n=6 ) and clenbuterol-treated (CLEB, n=6) . Clenbuterol was given in the drinking water (0.02 mg/mL) for 5 weeks. Post-treatment body weights were approximately 10% greater in the CLEB group compared to CANT (P<0.05) . In the SQL muscles of the CLEB group the wet weight and the ratio of muscle weight to body weight was significantly higher than the CANT (P<0.01), but not in the EDL. In the SOL muscles of the CLEB group the muscle type LDH isozyme distribution and enzymatic activity was significantly increased (P<0.01) . However, there was no metabolic change in the EDL muscles. Polyacrylamide gel electrophoresis (SDS-PAGE) of myosin heavy chain (Myosin-HC) indicated a clenbuterol-induced decrease (P<0.05) in the relative percentage of type I Myosin-HC with a concomitant increase (P<0.05) in Type II Myosin-HC in the SQL of the CLEB group. The Myosin-HC composition in the EDL was not altered. These findings suggest that clenbuterol may have induced selectively changes of muscle hypertrophy, the predominant anerobic glycolysis, and the transition of Myosin-HC in the SOL. The differences in the two muscles can be explained by the higher number of beta-2 receptors in slow-twitch muscles.

 The increase of female physicians and its undeveloped supporting system can be one of the causes of physicians' shortage. Although physicians' marriage/family perceptions and their influences on career choices have been extensively studied, those of medical students are not fully understood. An anonymous questionnaire survey was conducted involving male/female medical students in years 2 and 5 at Gifu University School of Medicine. The results showed that many male/female students hoped to get married, have children, and continue to work in the future, but different perceptions were demonstrated between the sexes with regards to the partners' occupation, working style, and influences of family/marriage perceptions on students' specialty choice. The results suggest the presence of sex-related differences in perceptions among medical students. The survey indicates the necessity of early undergraduate education for a better mutual understanding of gender issues.