Modification of the beta-adrenergic sensitivity of rat submandibular gland by constant light.
Rats exposed for 2, 5, 10, 20, 35 and 50 days to constant light (CL) showed beta-adrenergic desensitization of the submandibular gland as indicated by dose-response curves to 1.5, 2.0, 3.0, 10.0, 30.0 and 50.0 micrograms/kg isoproterenol. The phenomenon, evident with 1.5, 2.0 and 50.0 micrograms/kg after 2 days at CL, was more intense as time of exposure increased to reach values of about 50% those for controls after 20 days. After 35 and 50 days, desensitization showed some reversion, but the secretory responses were still lower than for controls maintained under a typical photoperiod. In the groups of rats exposed to CL for 20 days, gland wet and dry weights were higher (10%) than those of controls. These changes probably indicate an adaptation of the sympathetic control of salivary secretion induced by environmental illumination.
Gallara
R V
RV
Cátedras de Química Biológica, Facultad de Odontología, UniversidadNacional de Córdoba, Argentina.
Bellavia
S L
SL
D000818:Animals; D004305:Dose-Response Relationship, Drug; D007545:Isoproterenol / Q000494:pharmacology; D008027:Light; D008297:Male; D009929:Organ Size; D017440:Photoperiod; D051381:Rats; D017208:Rats, Wistar; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000528:radiation effects*; D012463:Saliva / Q000378:metabolism*; D012636:Secretory Rate; D013268:Stimulation, Chemical; D013363:Submandibular Gland / Q000187:drug effects / Q000294:innervation* / Q000378:metabolism* / Q000528:radiation effects
D011943:Receptors, Adrenergic, beta; D007545:Isoproterenol