A 52-year-old man from Delhi presents to the emergency department with severe headache, blurred vision, and epistaxis. His blood pressure is 210/140 mmHg. Fundoscopy reveals flame-shaped hemorrhages and cotton-wool spots. Serum creatinine is 2.8 mg/dL (baseline 1.0 mg/dL). Urinalysis shows 3+ proteinuria and RBC casts. Which of the following mechanisms is primarily responsible for the acute elevation in blood pressure in this patient?