H Uusitalo

The expression of Mas-receptor of the renin–angiotensin system in the human eye

PurposeThe local renin–angiotensin system has been held to be expressed in many organs, including the eye. It has an important role in the regulation of local fluid homeostasis, cell proliferation, fibrosis, and vascular tone. Mas-receptor (Mas-R) is a potential receptor acting mainly opposite to the well-known angiotensin II receptor type 1. The aim of this study was to determine if Mas-R is expressed in the human eye.MethodsSeven enucleated human eyes were used in immunohistochemical detection of Mas-R and its endogenous ligand angiotensin (1–7) [Ang(1–7)]. Both light microscopy and immunofluorescent detection methods were used. A human kidney preparation sample was used as control.ResultsThe Mas-R was found to have nuclear localization, and localized in the retinal nuclear layers and in the structures of the anterior segment of the eye. A cytoplasmic immunostaining pattern of Ang(1–7) was found in the inner and outer nuclear and plexiform layers of the retina and in the ciliary body.ConclusionTo the best of our knowledge, this is the first report showing Mas-R expression in the human eye. Its localization suggests that it may have a role in physiological and pathological processes in the anterior part of the eye and in the retina.

Overview of the profile of tafluprost

Purpose Tafluprost (Taflotan®) is a new potent PGF2_ analogue for the treatment of glaucoma. Tafluprost is the first prostaglandin available as a preservative free formulation. This presentation summarizes the pre-clinical and clinical profile of tafluprost. Results Tafluprost is a potent and selective FP receptor agonist. It lowers IOP by mainly increasing the uveoscleral outflow. Tafluprost had potent IOP lowering effect in normotensive and ocular hypertensive monkeys, unsurpassed by latanoprost. In healthy volunteers tafluprost was well tolerated, safe and effective in IOP lowering. Based on dose response data 15 micrograms/ml was chosen as the final concentration. This concentration had a comparable IOP lowering effect to latanoprost in P-II studies. Effective IOP lowering was confirmed in pivotal clinical studies. All adverse effects reported were well known for the prostaglandin analogues. The most frequently reported adverse event was hyperaemia. It was reported in 13% of patients. A preservative free form of tafluprost showed equal efficacy and pharmacokinetics to the preserved form. Preservative free tafluprost has low or no pro-apoptotic, pronecrotic or pro-oxidative effects in vitro compared to preservative-containing prostaglandin formulations latanoprost, travoprost and bimatoprost. Conclusion Tafluprost (Taflotan®) is a new effective, well tolerated and safe IOP reducing agent. Importantly Tafluprost is the first prostaglandin analogue commercially available as preservative-free formulation. There is a growing body of evidence that this has a clinical relevance in the treatment of chronic diseases like glaucoma and especially in patients with dry/sensitive eyes.