Propofol pharmacology and hemodynamic effects

A 68-year-old male with a history of hypertension and diabetes mellitus is undergoing emergency laparotomy for perforated peptic ulcer. Induction is planned with propofol. Intraoperatively, after intubation and initiation of mechanical ventilation with FiO₂ 0.5, his blood pressure drops from 130/80 mmHg to 85/50 mmHg within 2 minutes of propofol administration. Heart rate increases from 78 to 110 bpm. SpO₂ remains 98%. Which of the following mechanisms BEST explains the hemodynamic collapse in this patient?