The Dow Jones industrial average fell 43.72 to 5,626.88, Wednesday. Trading was relatively heavy at 402.84 million shares as of 4 p.m. The NYSE's composite index fell 1.94 to 348.09. The Standard & Poor's 500-stock index fell 4.06 to 648.91. The Nasdaq composite index fell 5.53 to 1,093.88. At the American Stock Exchange, the market value index fell 0.12 to 568.59. In London, gold closed at $400.05 up $ 0.10.