atrial-natriuretic-factor and Glaucoma

The expression of natriuretic peptides in the neural bundles of the anterior portion of the optic nerves and their functions in regulating vessel tone and blood flow may suggest a possible role in the pathogenesis of glaucoma. The purpose of this study was to investigate the association between normal-tension glaucoma and the genetic variations of atrial natriuretic peptide (Nppa) and natriuretic peptide receptor A (Npr1) gene.. Sixty-seven Korean normal-tension glaucoma (NTG) patients and 100 healthy subjects (as normal controls) were enrolled. DNA from peripheral blood leukocytes was extracted, and the genotypes of five polymorphisms (c.94G>A, c.454T>C, IVS1+16C>T, IVS2+701G>A, and c.-764C>G) in the Nppa gene and one polymorphism (c.1023G>C) in the Npr1 gene were determined using the restriction fragment length polymorphism and the SNaPshot methods. The genotype and allele frequencies of these polymorphisms in patients with NTG and normal controls were compared using the Fisher's exact test and the chi-square test.. In both groups, the genotype distributions were in accordance with the Hardy-Weinberg equilibrium. There was no significant difference in the frequency of the Nppa and Npr1 alleles or genotypes in the normal-tension glaucoma group as compared to the control group.. Nppa and Npr1 gene polymorphisms are not associated with normal-tension glaucoma, suggesting that this gene does not have an important role in the pathogenesis of optic neuropathy in this disease.

Topics: Adult; Atrial Natriuretic Factor; Female; Gene Frequency; Genotype; Glaucoma; Guanylate Cyclase; Humans; Intraocular Pressure; Male; Middle Aged; Polymorphism, Single Nucleotide; Receptors, Atrial Natriuretic Factor

To measure aqueous humour levels of brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) in humans. To compare peptide levels in glaucomatous and control eyes to test the hypothesis that these peptides are increased in glaucoma. BNP and ANP are cyclic endopeptides whose principal biological effects are natriuresis and vasodilatation. Experimental glaucoma in animal models results in elevated aqueous ANP. Intravenous ANP administration in both animals and humans causes lowering of intraocular pressure (IOP). There are equivocal data to support a role for ANP in IOP regulation in human eyes. There are as yet no published data on BNP in human aqueous humour.. This was a case-control study. Cases were primary open angle, pseudoexfoliation, and mixed mechanism glaucoma eyes undergoing trabeculectomy. Controls were cataract extraction eyes. There were 47 trabeculectomy eyes (44 patients) and 47 cataract extraction eyes (46 patients) matched for age, sex, race, systemic medications, and type of anaesthetic. 100-200 microliters of aqueous humour were aspirated by paracentesis as the first step in the surgical procedure. Peptide levels were later measured by radioimmunoassay.. The presence of BNP and ANP in human aqueous humour was confirmed. BNP was present in higher concentrations than ANP. BNP levels tended to be greater in control eyes--glaucoma median 56.5 (range 0-3526.5) pg/ml versus control median 65.16 (range 0-1788) pg/ml (Wilcoxon signed rank test p = 0.78). ANP levels tended to be greater in glaucoma eyes than in controls: glaucoma median 3 (range 0-68.5) pg/ml versus control median 0 (range 0-60) pg/ml (Wilcoxon signed rank test p = 0.82). ANP and BNP were log linearly related in both groups (r glaucoma group = 0.961, r control group = 0.894).. This is the first report of BNP and ANP in human aqueous humour. Peptide levels did not differ significantly between glaucoma and cataract extraction eyes. A linear relation between log BNP and ANP was found. Further studies are required to clarify the role of these peptides in aqueous humour production and IOP regulation.

Topics: Adult; Aged; Aged, 80 and over; Aqueous Humor; Atrial Natriuretic Factor; Biomarkers; Case-Control Studies; Female; Glaucoma; Humans; Male; Middle Aged; Natriuretic Peptide, Brain; Trabeculectomy

ANF binding sites were analysed in the ciliary processes of rabbits with unilateral experimental glaucoma which had been induced by injecting alpha-chymotrypsin into the posterior chamber of the right eyes. The intraocular pressure (IOP) of glaucomatous eyes was significantly greater (28.4 +/- 4 mmHg) than that of normotensive control eyes (13.1 +/- 1.4 mmHg, mean +/- S.E.M., n = 23, P less than 0.05). ANF concentrations in aqueous humour and the ciliary processes were significantly higher in glaucomatous eyes (91 +/- 2 pg ml-1 and 30.4 +/- 4.2 pg g-1 wet weight) than in normal eyes (3.1 +/- 2.2 pg ml-1 and 10.2 +/- 2.7 pg g-1 wet weight, respectively, n = 6, P less than 0.01). The number of ANF-binding sites (Bmax) in the ciliary processes of glaucomatous rabbit eyes was significantly decreased in comparison to the controls (24 +/- 4 vs. 13 +/- 3 fmol mg-1 protein, n = 10, P less than 0.05). These data suggest that ANF receptors in the ciliary processes are down-regulated and that ANF may play an important role in the pathophysiology of experimental glaucoma.

Topics: Animals; Aqueous Humor; Atrial Natriuretic Factor; Binding Sites; Chymotrypsin; Ciliary Body; Glaucoma; Intraocular Pressure; Rabbits; Receptors, Atrial Natriuretic Factor; Receptors, Cell Surface

Atrial natriuretic factor (ANF) concentration in the aqueous humor (AH) was studied in rabbits with experimental glaucoma induced by injecting alpha-chymotrypsin into the posterior chamber. In normal rabbit eyes, the ANF concentration in AH was 3.1 +/- 1.2 pg/ml (mean +/- SEM; n = 12), ranging from 0 to 5.8 pg/ml, whereas it was significantly higher in AH from glaucomatous rabbit eyes, being 81.0 +/- 9.8 pg/ml (n = 12). These findings were correlated with intraocular pressure (IOP), which was 13.0 +/- 2.4 mmHg (n = 12) in normal rabbit eyes and significantly greater in glaucomatous eyes: 24.4 +/- 3.0 mmHg (n = 12). Our data indicate that enhanced ANF release in AH during experimental glaucoma may play an important physiological role in modulating IOP.

Topics: Animals; Aqueous Humor; Atrial Natriuretic Factor; Chymotrypsin; Eye; Glaucoma; Male; Rabbits

The human atrial natriuretic factor (hANF) is a cardiovascular hormone, which promotes renal sodium secretion in response to increases in extracellular fluid volume and atrial pressure. It regulates sodium and volume homeostasis. Specific receptors for hANF have been identified in the ciliary processes of rats and rabbits, which mediated a long-lasting reduction in intraocular pressure (IOP) after intra-atrial injection. In a series of 10 glaucoma patients with bilateral IOP elevations above 33 mmHg an i.v. bolus injection of hANF was administered and IOP was recorded before and over an 8-h period after injection. The human atrial natriuretic factor lowered IOP significantly. The potential of hANF as an antiglaucoma agent is discussed.

Topics: Atrial Natriuretic Factor; Glaucoma; Humans; Infusions, Intravenous; Intraocular Pressure

In an open label, single dose study on ten glaucoma patients with bilateral untreated IOP levels exceeding 30 mmHg the effects of 100 micrograms human atrial natriuretic factor (HANF) on IOP, systolic blood pressure, pulse rate and serum electrolytes were investigated. The intravenous application of HANF decreased IOP over more than 8 hrs. The magnitude of IOP reduction in this study was in the range of 4-7 mmHg. There was no significant change in blood pressure, pulse rate or serum electrolytes. The verified, yet still limited efficacy of HANF on IOP in glaucoma warrants further investigations.

Topics: Atrial Natriuretic Factor; Blood Pressure; Electrolytes; Glaucoma; Humans; Intraocular Pressure; Pulse; Time Factors