both anterior and posterior segment and decreased the expression of inflammatory cytokines. Thus, it is possible that one or more of these pathways may be related to the action of DIZE in IOP lowering effect. It should be observed that the trauma associated with the cannulation of the anterior chamber in our model can lead to activation of an inflammatory response, which can contribute to the increased IOP. Also, the large amount of HA may itself contribute to the inflammation in the anterior chamber. Therefore, at the moment, we can not rule out the possibility that the beneficial effect of DIZE was due to acting in the inflammatory process associated to the model and future studies should be conducted in other animal models of chronic IOP elevation for further understanding the underlying mechanisms involved in the DIZE IOP lowering effect. It is worthy of note that DIZE was able to produce a reduction in IOP much greater than any commercially available compound. This finding may be related to the fact that ACE2 plays a double role in the RAS, i.e. it degrades Ang II and generates Ang-. Ang II increases the IOP of normal rats and decreases the drainage of aqueous humor in primates and in rabbits. Also, it has been demonstrated the presence of polymorphisms of the Ang II type 1 receptor gene in patients with primary open angle glaucoma. On the other hand, Ang- is a heptapeptide that promotes vasodilation and antihypertensive effects which are 14 / 18 Ocular Inserts of DIZE to Treat Glaucoma in Rats counterregulatory actions to the Ang II effects. Thus, activation of ACE2 might reduce IOP through both degrading Ang II and forming Ang-. Furthermore, increased ACE2 action and expression is observed when ACE2 activators are administered. This strongly suggests that these compounds induce their beneficial effects not only by forming Ang- and/or degrading Ang II, but also through an unidentified mechanism that is able to increase the expression of ACE2. Drugs that promote IOP lowering effects act reducing the production of aqueous humor or increasing the drainage thereof. In this context, we can not rule out the possibility that drugs able to modulate the RAS can act in this two ways. In a previous study, we demonstrated that DIZE increased the drainage of aqueous humor and it has been suggested that captopril, an ACE inhibitor, reduces the aqueous humor production. ACE inhibitors appear to promote synthesis of prostaglandins, increases in bradykinin levels, NO release and reduction PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19747578 in the formation of the vasoconstrictor peptide endothelin-1, which could consequently reduce IOP. Thus, PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19748727 it is possible that one or more of these factors may contribute to the profound IOP reduction induced by DIZE. Neuroprotective mechanisms also appear to be involved in the effects of D+I on glaucoma. We found characteristic optic nerve head cupping, death of RGC and axonal loss in control glaucomatous UNC0642 biological activity animals and in glaucomatous rats treated with placebo inserts. The D+I were able to decrease the death of RGC, as well as the optic nerve head cupping. Nowadays, neuroprotective agents are under extensive investigation since almost all drug therapies for treatment of glaucoma are based on lowering IOP or preventing the increase of IOP. Thus, classical agents often did not avoid RGC 
death leading to progressive vision loss. Consequently, there is a great interest in developing agents that not only reduce IOP but also promote neuroprotection. Biodistribution studi
