In a small bowl, combine vinegar, sugar, salt, pepper and 1 tablespoon of reserved tuna liquid. In a large bowl combine remaining ingredients; add vinegar mixture and toss. Let stand for 10 minutes; toss again and serve. Each serving (1-1/2 cups) provides: * 2-1/4 V, 1 P, 1-1/4 B, 10 C Per serving: * 274 cal, 22 g pro, 4 g car, * 1 g fat: 0 g poly, 0 g mono, 0 g sat * 538 mg sod, 24 mg chol