title: Induction of psoriasiform changes in guinea pig skin by propranolol.
abstract: BACKGROUND
  The ability of beta-adrenergic blocking agents to induce psoriasis as an adverse effect prompted us to use such an agent to induce psoriasis in guinea pigs.
  
  
  METHODS
  Thirty female albino guinea pigs were divided into four groups. Group 1 received propranolol, 0.1 mg/day, dissolved in 2 mL of normal saline, orally by gavage for 30 days. Group 2 was given the same treatment, but in addition intradermal injections of propranolol with Freund's complete adjuvant, injected at weekly intervals. Group 3 (five animals) received 2 mL saline, and group 4 additional injections of adjuvant without propranolol. Groups 3 and 4 served as normal controls.
  
  
  RESULTS
  All animals of group 2 (which received propranolol orally and in addition intradermal injections of adjuvant) developed psoriasiform epidermal hyperplasia with acanthosis. Parakeratosis, papillomatosis, and formation of microabscesses, all characteristic signs of psoriasis, have not been seen in any of the skin samples of this group. Skin samples from group 1 animals receiving propranolol orally showed normal epidermis and dermis. They showed exactly the same histologic picture as the control groups 3 and 4.
  
  
  CONCLUSIONS
  Beta-blockers given orally for 30 days do not cause any significant skin changes in guinea pigs. When given with a weekly intradermal injection of Freund's complete adjuvant, they cause psoriasiform epidermal hyperplasia. Although the overall histologic appearance of the skin of group 2 resembled psoriasis, it lacked important histologic features characteristic of this disease. It seems, therefore, that the model, per se, does not fulfill the initial expectations as an experimental model for psoriasis; however, this model has potential in the study of adverse drug reactions. Perhaps by introducing modifications to the experimental protocol, we may succeed also in developing a better model for experimental psoriasis.
authors: Department of Dermatology, Tel-Aviv Sourasky Medical Center, Ichilov Hospital, Israel.
authors: R
authors: R
authors: Wolf
authors: H
authors: H
authors: Shechter
authors: S
authors: S
authors: Brenner
mesh_terms: D000038:Abscess / Q000473:pathology; D000284:Administration, Oral; D000505:Alopecia / Q000139:chemically induced / Q000473:pathology; D000818:Animals; D004195:Disease Models, Animal; D004817:Epidermis / Q000187:drug effects / Q000473:pathology; D005260:Female; D005620:Freund's Adjuvant / Q000008:administration & dosage; D006168:Guinea Pigs; D006197:Hair / Q000187:drug effects / Q000473:pathology; D006965:Hyperplasia; D007271:Injections, Intradermal; D007642:Keratosis / Q000473:pathology; D010212:Papilloma / Q000473:pathology; D011433:Propranolol / Q000008:administration & dosage / Q000009:adverse effects*; D011565:Psoriasis / Q000139:chemically induced* / Q000473:pathology; D012627:Sebaceous Glands / Q000187:drug effects / Q000473:pathology; D012867:Skin / Q000187:drug effects* / Q000473:pathology; D012878:Skin Neoplasms / Q000473:pathology
chemical_list: D005620:Freund's Adjuvant; D011433:Propranolol