The spot rupee slipped to 43.70 per dollar on buying by PSU banks and greenback rally in the overseas markets today.Sentiment was bullish in the government securities market, and prices firmed up on sustained buying. While prices of long-term papers went up by 50 paise, medium and short-term papers moved up in the range of 15-35 paise. The benchmark 7.38% 2,015 bond closed at an yield of 6.54%.Call rates were steady at 4.70-4.80%, and reverse repo bids totalled Rs 16,000 crore.