Complex sentence: Thrombolysis involves the administration of medication that activates the enzymes that normally destroy blood clots; the first thrombolysis agent was streptokinase, but the most thrombolysis agents used currently are artificial forms of the human enzyme tissue plasminogen activator (tPA): reteplase, alteplase and tenecteplase.
Split into simpler sentences: Thrombolysis involves the administration of medication that activates the enzymes that normally destroy blood clots. The first thrombolysis agent was streptokinase, but most thrombolysis agents used currently are artificial forms of the human enzyme tissue plasminogen activator (tPA): reteplase, alteplase and tenecteplase.