Tokyo stocks opened lower Wednesday as exporter issues were sold after the yen strengthened against the U.S. dollar overnight in response to falling long-term U.S. interest rates. In the first 15 minutes of trading, the 225-issue Nikkei Stock Average fell 381.84 points, or 0.98 percent, from Tuesday to 38,455.62. The broader Topix index was down 35.99 points, or 1.29 percent, at 2,751.49. On the top-tier Prime Market, decliners were led by marine transportation, mining and transportation equipment issues. At 9 a.m., the dollar fetched 155.11-12 yen compared with 154.86-96 yen in New York and 1…