title: Some photoresponses of isolated tissue preparations to ultraviolet light in the presence of photosensitizers.
abstract: Responses of isolated tissue preparations to ultraviolet (UV) light were studied with and without the presence of photosensitizers like eosin, fluorescein and sodium nitrite. Exposure to UV light in the presence of sodium nitrite induced consistent relaxation of rat duodenum. The photorelaxation was found to be related to the concentration of sodium nitrite. Adrenergic or cholinergic mechanisms do not seem to be involved. The isolated rat duodenum preparation exhibited quantitatively consistent photoresponse for 3 to 4 hr at its normal tone obviating the need for additional spasmogens as needed with other preparations. The preparation is a suitable test model for the study of photobiologic response evoked by UV light.
mesh_terms: D000818:Animals; D001001:Anura; D004801:Eosine Yellowish-(YS) / Q000494:pharmacology; D005452:Fluoresceins / Q000494:pharmacology*; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects / Q000528:radiation effects*; D066298:In Vitro Techniques; D009130:Muscle, Smooth / Q000187:drug effects / Q000528:radiation effects*; D009132:Muscles / Q000187:drug effects / Q000528:radiation effects*; D009469:Neuromuscular Junction / Q000187:drug effects / Q000528:radiation effects; D009573:Nitrites / Q000494:pharmacology*; D011817:Rabbits; D051381:Rats; D012977:Sodium Nitrite / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D005452:Fluoresceins; D009573:Nitrites; D012977:Sodium Nitrite; D004801:Eosine Yellowish-(YS)