Alpha 1-adrenergic agonist-stimulated protein secretion in rat exorbital lacrimal gland acini.
The alpha-adrenergic stimulation by phenylephrine of lacrimal gland protein secretion was pharmacologically characterized. Acini, prepared from rat exorbital lacrimal glands, were incubated with agonists, antagonists or both for 0-20 min. Peroxidase secretion, an index of protein secretion, was measured spectrophotometrically. Peroxidase secretion was stimulated by the alpha 1-adrenergic agonists clonidine. The non-selective alpha-adrenergic antagonist phentolamine completely inhibited phenylephrine-induced secretion. The selective alpha 1-adrenergic alkylating agent phenoxybenzamine and the selective alpha 1-adrenergic antagonist prazosin partially inhibited phenylephrine-induced secretion. The alpha 2-adrenergic antagonist yohimbine, the beta-adrenergic antagonist timolol, and the dopaminergic antagonist haloperidol also inhibited phenylephrine-induced secretion but were 100-fold less potent than prazosin. It is concluded that phenylephrine activates an alpha 1-adrenergic pathway, but not an alpha 2-adrenergic, beta-adrenergic or dopaminergic pathway, to stimulate lacrimal gland protein secretion from acini.
Dartt
D A
DA
Schepens Eye Research Institute, Boston, MA 02114.
Rose
P E
PE
Dicker
D M
DM
Ronco
L V
LV
Hodges
R R
RR
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D005136:Eye Proteins / Q000378:metabolism; D006220:Haloperidol / Q000494:pharmacology; D007765:Lacrimal Apparatus / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D008297:Male; D008729:Methoxamine / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology; D009195:Peroxidase / Q000378:metabolism*; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013999:Timolol / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D005136:Eye Proteins; D010656:Phenylephrine; D013999:Timolol; D009195:Peroxidase; D008729:Methoxamine; D006220:Haloperidol; D003000:Clonidine; D009638:Norepinephrine