Abstract
Purpose:
To compare and analyze cholesterol profiles in the trabecular meshwork of DBA/2J mice in normotensive and hypertensive states.
Methods:
This research adhered to ARVO statement for use of animals in research. The normotensive and hypertensive DBA/2J mice (n=40 each per gender) were used. Normotensive mice had intraocular pressure (IOP) ≤15 mm of Hg (≤6 months old) and hypertensive mice were had IOP 25-36 mm of Hg (8-9 months old). IOP measurements were taken using Tonolab twice daily; mice TM was removed surgically by established protocols post euthanasia. TM tissues were subjected to lipid extraction using suitable modification of the Bligh and Dryer method. Proteins were quantified using the Bradford method. Cholesterols were analyzed using a triple quadrupole mass spectrometer. A parent ion scan was set in positive ion mode with a collision energy of 22, m/z of 97.1 for cholesterol and scans ranged from 200 to 1000. Lipids were quantified using internal standards in a two-step ratiometric process. MZmine 2.9 software was used to identify the lipid species using Lipidmaps database.
Results:
We found 11 unique cholesterol species in the normotensive DBA/2J males, 22 unique cholesterols in normotensive females, 13 unique cholesterols in hypertensive males, and 9 unique cholesterols in hypertensive females. Importantly we found 15 alpha-hydroxycholestane at a higher level in hypertensive state in both male and female DBA/2J mice TM compared to normotensive state.
Conclusions:
We found unique cholesterol species in normotensive and hypertensive stages of DBA/2J mice trabecular meshwork. Further investigation will reveal the contribution of these cholesterols towards TM material properties.
Keywords: 583 lipids •
633 outflow: trabecular meshwork •
568 intraocular pressure