We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Delayed phase of Hematoporphyrin-Induced Phototoxicity: Modulation by Complement, Leukocytes, and Antihistamines.
- Authors
Lim, Henry W.; Young, Lorraine; Hagan, Michael; Gigli, Irma
- Abstract
We have investigated the role of complement, leukocytes, and histamine in the delayed phase of hematoporphyrin-induced phototoxicity in guinea pigs. The phototoxic response was quantified by the accumulation of intravenously injected [125I]bovine serum albumin in the skin. There was a greater than 6-fold increase in the vascular response at the completion of irradiation, which subsided partially to reach a plateau of twice the preirradiation level between 0.5 h and 12 h. At 18 h the vascular responsiveness returned to the baseline value. The 7 h timepoint was selected in this study to evaluate the modulation of the delayed phase. In complement-depleted guinea pigs, as well as in leukopenic animals, the enhancement in the vascular response was significantly suppressed (p vs control, < 0.0001 and 0.0022. respectively). Cimetidine, when administered prior to irradiation, significantly suppressed the phototoxic response (p vs control, 0.0365). The combination of diphenhydramine and cimetidine, administered 6 h after the induction of phototoxicity, also suppressed the vascular response (p vs control, < 0.0001). These data indicate that the expression of the delayed phase of hematoporphyrin-iuduced phototoxicity, similar to the early phase, requires the presence of an intact complement system, leukocytes, and histamine.
- Subjects
HEMATOPORPHYRIN; LEUCOCYTES; ANTIHISTAMINES; ANTIALLERGIC agents; CIMETIDINE; IRRADIATION
- Publication
Journal of Investigative Dermatology, 1985, Vol 84, Issue 2, p114
- ISSN
0022-202X
- Publication type
Article
- DOI
10.1111/1523-1747.ep12275345