title: ADRB1 and ADBR2 gene polymorphisms and the ocular hypotensive response to topical betaxolol in healthy Mexican subjects.
abstract: BACKGROUND
  The β adrenergic receptors (ADRB) are expressed in the ciliary body and trabecular meshwork, structures involved in aqueous humor production and outflow, respectively. ADRB are members of the adrenergic family of G-protein-coupled receptors. Topic β blockers have a good local and systemic tolerance; they reduce the aqueous humor production and eye strain blocking the ADRB of the ciliary body and interfering with adenylate cyclase. However, the ocular hypotensive response is not the same in all patients and could be mediated by the polymorphisms of the ADRB genes.
  
  
  METHODS
  Seventy-two healthy subjects were studied after treatment with topical betaxolol in both eyes. We analyzed ADRB1 and ADRB2 gene polymorphisms by PCR and automated DNA sequencing.
  
  
  RESULTS
  There was statistically significant difference between baseline intraocular pressure (IOP) and final IOP of both eyes (baseline IOP 16.2 ± 1.2 - follow-up IOP 13.6 ± 2.0 (mean difference-2.5 ± 1.3, p < 0.001). Gly389 had a higher baseline IOP than Arg389 (17.0 ± 1.2 mmHg versus 16.0 ± 1.2 mmHg; p = 0.02), and conversely Arg389 had a greater magnitude of response than Gly389 to betaxolol therapy (-2.9 ± 1.1 mmHg versus -0.7 ± 0.4 mmHg; p < 0.001). Gln27 had a higher response than Glu27 (-2.7 ± 1.3 mmHg versus -1.9 ± 1.0; p = 0.02).
  
  
  CONCLUSIONS
  Arg389 polymorphism of the ADRB1 gene and Gln27 polymorphism of the ADRB2 gene were associated with the hypotensive response to topic betaxolol in healthy Mexican volunteers.
authors.affiliation: Department of Ophtalmology .
authors.forename: Olga
authors.initials: O
authors.lastname: Messina Baas
authors.forename: Guillermo
authors.initials: G
authors.lastname: Pacheco Cuellar
authors.forename: Jaime
authors.initials: J
authors.lastname: Toral-López
authors.forename: Silvia Fanny
authors.initials: SF
authors.lastname: Lara Huerta
authors.forename: Luz María
authors.initials: LM
authors.lastname: Gonzalez-Huerta
authors.forename: Héctor
authors.initials: H
authors.lastname: Urueta-Cuellar
authors.forename: Ma Refugio
authors.initials: MR
authors.lastname: Rivera-Vega
authors.forename: Ignacio
authors.initials: I
authors.lastname: Babayan-Mena
authors.forename: Sergio A
authors.initials: SA
authors.lastname: Cuevas-Covarrubias
mesh_terms: D000287:Administration, Topical; D058671:Adrenergic beta-1 Receptor Antagonists / Q000008:administration & dosage*; D000328:Adult; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use; D015784:Betaxolol / Q000008:administration & dosage*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects* / Q000235:genetics; D008297:Male; D008800:Mexico; D008875:Middle Aged; D015814:Ocular Hypotension / Q000139:chemically induced / Q000235:genetics; D009883:Ophthalmic Solutions; D016133:Polymerase Chain Reaction; D020641:Polymorphism, Single Nucleotide; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics*; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics*; D014065:Tonometry, Ocular
chemical_list: C547787:ADRB1 protein, human; C553443:ADRB2 protein, human; D058671:Adrenergic beta-1 Receptor Antagonists; D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions; D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; D015784:Betaxolol
keywords: ADRB1 gene; ADRB2 gene; betaxolol; polymorphism