Beta-adrenoceptors in the extraorbital lacrimal gland of the Syrian hamster. Characterization with [125I]-iodopindolol and evidence of sexual dimorphism.
Saturation and competition experiments with the radiolabeled beta-adrenergic antagonist (--)-[125I]-iodopindolol were used to characterized beta-adrenoceptor density (Bmax) and receptor affinity in the extraorbital lacrimal gland of male and female Syrian hamsters. Specific binding to the receptor was saturable. Scatchard analysis of saturation isotherms revealed a single population of receptor sites. Male glands had a significantly higher Bmax (38.9 +/- 5.0 vs. 23.3 +/- 2.1 fmol/mg protein, means +/- SEM, p less than 0.02) and receptor affinity (expressed in a lower dissociation constant Kd: 0.065 +/- 0.013 vs. 0.120 +/- 0.015 nM, p less than 0.02) than female glands. Binding of the radiolabeled ligand in competition with various adrenergic antagonists showed the receptor to be stereospecific and of the beta 2-subtype.
Pangerl
A
A
Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas.
Pangerl
B
B
Jones
D J
DJ
Reiter
R J
RJ
D000319:Adrenergic beta-Antagonists; D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D006224:Cricetinae; D005260:Female; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D007765:Lacrimal Apparatus / Q000378:metabolism*; D008297:Male; D008566:Membranes / Q000187:drug effects / Q000378:metabolism; D008647:Mesocricetus; D010869:Pindolol / Q000031:analogs & derivatives*; D011506:Proteins / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*; D012727:Sex Characteristics
D000319:Adrenergic beta-Antagonists; D007457:Iodine Radioisotopes; D011506:Proteins; D011943:Receptors, Adrenergic, beta; C029247:3-iodopindolol; D010869:Pindolol