Objective   To explore the effect of hypericin (HY) combined with 525 nm photodynamic therapy (PDT) on vascular lesion of cock comb as the model of port wine stains.    Methods   Totally 36 Longman cocks at the age of 6 months were divided into 6 groups randomly

including control group

irradiation group

positive control group (hemoporphyrin 1 mg/kg)

0.3 mg/kg HY group

1 mg/kg HY group

and 3 mg/kg HY group. Aspots of 2.0 cm in diameter on one side of cock comb w

as irradiated by 525 nm laser at a power density of 100 mW/cm

2

immediately after corresponding photosensitiser intravenous injection. While the other side of cock comb served as control and received no irradiation. Visual observation and photos were recorded every day

pathological changes were observed and the reduction rate of comb’s capillary of all groups was counted in 7 and 14 d after photodynamic therapy.    Results   HY and 1 mg/kg hemoporphyrin damaged the epidermis

such as edema

necrosis and incrustation

and abated the red color of cock bomb obviously

especially in groups of 1 and 3 mg/kg HY combined with 1 mg/kg hemoporphyrin injection. At the same time

epidermis hyperplasia

and the reduction rate of comb’s capillary were decreased by HY and hemoporphyrin with 525 nm photodynamic therapy. Control group and irradiation group had no such changes (P0.05).    Conclusion   Intravenous injection of HY associated with photodynamic irradiation at 525 nm is proved to have effective damage to cutaneous micrangium of cock comb.