The alpha1- and beta1-adrenergic modulation of lacrimal gland function in the mouse.
OBJECTIVE
To determine the expression patterns of alpha(1)- and beta(1)-adrenergic receptors in the mouse exorbital lacrimal gland (LG). An alpha- and beta-receptor agonist and antagonist were used to elucidate the receptors' relevance to protein secretion.


METHODS
Mouse LGs were processed for single- and double-labeled indirect immunofluorescence studies and examined with confocal scanning microscopy. Protein secretion was measured from gland fragments in response to adrenergic agonists.


RESULTS
Extensive alpha(1)-immunoreactivity (IR) was found on the surface and cytoplasm of acinar cells and much more alpha(1)-IR in the interstitial areas. In contrast, more beta(1)-IR was found in the LG, and most beta(1)-IR appeared to concentrate in the cytoplasm of acinar cells, with almost no beta(1)-IR in the interstitial areas. The protein secretion in response to phenylephrine and isoproterenol showed that direct stimulation of either the alpha(1)- or beta(1)-receptor could induce significant protein secretion from LGs. The specificity of this stimulation was further indicated by the effects of adrenergic antagonists. No synergism was observed between alpha(1)- and beta-receptor-mediated protein secretions.


CONCLUSIONS
The results support the notion that there is extensive adrenergic control in the mouse LG. The adrenergic receptors may be a better choice of markers, compared with tyrosine hydroxylase and dopamine beta-hydroxylase, to reflect the extent of adrenergic control because circulating norepinephrine in the bloodstream should be taken into consideration. Both confocal microscopy observations and protein secretion data suggest the presence of alpha(1)- and beta(1)-mediated pathways in the mouse LG.
Ding
Chuanqing
C
Department of Cell and Neurobiology, University of Southern California, Keck School of Medicine, 1333 San Pablo Street, Los Angeles, CA 09989, USA. cding@usc.edu
Walcott
Benjamin
B
Keyser
Kent T
KT
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D005136:Eye Proteins / Q000378:metabolism; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D007765:Lacrimal Apparatus / Q000187:drug effects / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism*
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D005136:Eye Proteins; D018340:Receptors, Adrenergic, alpha-1; D018342:Receptors, Adrenergic, beta-1