Tokyo stocks opened lower Friday, weighed down by a cautious mood ahead of Japan’s general election and selling of exporter issues on a stronger yen against the U.S. dollar. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average fell 214.62 points, or 0.56 percent, from Thursday to 37,928.67. The broader Topix index was down 11.44 points, or 0.43 percent, at 2,624.13. On the top-tier Prime Market, decliners were led by pharmaceutical, service and bank shares. At 9 a.m., the dollar fetched 151.78-80 yen compared with 151.79-89 yen in New York and 152.12-14 yen in Tokyo at 5 p.m….