Two suspects sought in connection with three slayings in East San Diego in April were arrested Wednesday by Los Angeles police. Hector Ayala and his brother, Ronald Ayala, were arrested and being held on suspicion of murder in connection with the deaths of three men who had been bound and gagged and were found shot to death inside the A & C Auto Repair Shop on 43rd Street April 26. Each of the victims--Jose Rositas, Marco Zamora and Ernesto Dominguez -had been shot in the head, police said. A fourth man, Pedro Castrillo, also was shot but survived. Los Angeles police said that the victims and the suspects were members of rival gangs. San Diego police were en route to Los Angeles late Wednesday night to pick up the suspects. A third suspect in the slayings, Joseph Moreno, remains at large, police said.