Inhibition and facilitation of lacrimal flow by beta-adrenergic drugs.
The effects of adrenergic beta-stimulating and beta-blocking compounds on tear flow were studied in conscious rabbits with a modified Schirmer technique. The tear flow was significantly increased by the unselective beta-adrenergic agonist isoprenaline and by the selective beta1-agonist H 80/62 (racemic Prenalterol, Hässle, Sweden). The effects of the agonists were blocked by the unselective beta-adrenergic antagonist propranolol (Inderal) and by the selective beta1-antagonist metoprolol (Seloken, Lopressor). The experimental data favoured the hypothesis that the beta-receptors involved in the regulation of the tear flow were of the beta1-type. The anatomical location of these beta-receptors is at present unclear but in vitro experiments performed on the rabbit lacrimal glands indicated that the receptors were probably not located on cholinergic nerve-endings as the release of acetylcholine was not influenced by isoprenaline.
D000109:Acetylcholine / Q000378:metabolism; D000318:Adrenergic beta-Agonists / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D002799:Cholinergic Fibers / Q000187:drug effects; D004558:Electric Stimulation; D006339:Heart Rate / Q000187:drug effects; D007545:Isoproterenol / Q000494:pharmacology; D007765:Lacrimal Apparatus / Q000187:drug effects* / Q000294:innervation / Q000502:physiology; D008790:Metoprolol / Q000494:pharmacology; D009924:Organ Culture Techniques; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology; D012636:Secretory Rate / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D013666:Tears / Q000378:metabolism*
D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D011943:Receptors, Adrenergic, beta; D012965:Sodium Chloride; D011433:Propranolol; D008790:Metoprolol; D007545:Isoproterenol; D000109:Acetylcholine