Needs of interoperability are getting increased since there have been some issues in heterogeneous wireless sensor networks such as information exchange, network protocol conversion, and integrity among multi-vendor products. We propose message-oriented middleware to make use of an intelligent bridge for information exchange in heterogeneous constraints. It includes middleware architecture, a message format and message types, and rule handling. We present the results of a case study in details to do demonstrate the feasibility of our approach. These are composed of three parts: First, we build a scenario based on an information exchange between wireless sensor networks in home environment so that it shows roles of a bridge, handling sensed events. Second, we define a process of information exchange using UML sequence diagram. Third, we represent soap messages which contain methods and data defined in advance. We confirm effectiveness of information exchange mechanism with extensibility and flexibility through the case study.