Prostaglandin B2-lnduced Cutaneous Vasoconstriction of the Canine

The cutaneous vascular effects of prostaglandin B2 (PGB2) were studied in dogs during constant-flow perfusion of the hind paw. The effects of PGB2 (50-800 ng/kg min" , ia) on systemic pressure, hind-paw perfusion pressure, and responses to local heating at 45°C (30 seconds) and cooling at 4°C (90 seconds) were measured in 44 dogs. PGB2 increased perfusion pressure by 50 ± 19 mm Hg to 218 ± 21 mm Hg without any effect on systemic arterial blood pressure. The pressor response to cooling increased from 34 mm Hg to 53 mm Hg (50 ng/kg min~PGB2), but the dilator response to heating was reduced significantly during infusions of PGB2 (50 and 100 ng/kg). Acute denervation and reserpine treatment (0.5 mg/kg dog" for 2 days) reduced the constrictor responses to PGB2. The abilities of PGB2 to produce intense vasoconstriction, which is blocked by acute denervation and reserpine, to enhance responses to cooling, and to antagonize responses to heating make this preparation a useful model for the study of Raynaud's phenomenon and suggest that a prostaglandin, perhaps PGB2, may participate in cutaneous vasospastic disorders.