PURPOSE: An active local renin-angiotensin system (RAS) has recently been found in the human eye. The aim of the present study was to compare the activities of central RAS enzymes (ACE1 and 2) in porcine ocular tissues, morphologically and physiologically close to the human eye. In addition, the effects of three ACE-inhibitory tripeptides on these enzymes were evaluated. METHODS: Enucleated fresh porcine eyes were used. Activities of ACE1 and ACE2 and their inhibition by bioactive tripeptides (Ile-Pro-Pro, Val-Pro-Pro, Leu-Pro-Pro) as well as by a standard ACE-inhibitor captopril were assayed in the vitreous body, the retina and the ciliary body using fluorometric detection methods. RESULTS: Activity of ACE1 as well as ACE2 was found in all tissues evaluated. ACE1 activity was markedly higher in the ciliary body (3.7 +/- 0.7 mU/mg protein) than in retina (0.2 +/- 0.02 mU/mg), whereas ACE2 activities in the ciliary body (0.2 +/- 0.02 mU/mg) and retina (0.2 +/- 0.01 mU/mg) were at the same level. In the vitreous body ACE1 activity (8.2 +/- 0.31 nmol/min/mL) was manifold compared to that of ACE2 (0.1 +/- 0.02 nmol/min/mL). The tripeptides inhibited ACE1 at one-thousandth of the concentration needed to inhibit ACE2. All peptides studied evinced about equal inhibitory activities. CONCLUSION: To our knowledge the present findings constitute the first evidence of ACE2 activity in the ciliary and vitreous bodies, in addition to previously described activity in the retina. The known favorable effects of ACE2 products vs. those of ACE1 suggest a counterbalancing interaction of these two enzyme homologues in physiological regulation of ocular circulation and pressure and possible protective role in certain ophthalmic disorders such as glaucoma and diabetic retinopathy.
PURPOSE: An active local renin-angiotensin system (RAS) has recently been found in the human eye. The aim of the present study was to compare the activities of central RAS enzymes (ACE1 and 2) in porcine ocular tissues, morphologically and physiologically close to the human eye. In addition, the effects of three ACE-inhibitory tripeptides on these enzymes were evaluated. METHODS: Enucleated fresh porcine eyes were used. Activities of ACE1 and ACE2 and their inhibition by bioactive tripeptides (Ile-Pro-Pro, Val-Pro-Pro, Leu-Pro-Pro) as well as by a standard ACE-inhibitor captopril were assayed in the vitreous body, the retina and the ciliary body using fluorometric detection methods. RESULTS: Activity of ACE1 as well as ACE2 was found in all tissues evaluated. ACE1 activity was markedly higher in the ciliary body (3.7 +/- 0.7 mU/mg protein) than in retina (0.2 +/- 0.02 mU/mg), whereas ACE2 activities in the ciliary body (0.2 +/- 0.02 mU/mg) and retina (0.2 +/- 0.01 mU/mg) were at the same level. In the vitreous body ACE1 activity (8.2 +/- 0.31 nmol/min/mL) was manifold compared to that of ACE2 (0.1 +/- 0.02 nmol/min/mL). The tripeptides inhibited ACE1 at one-thousandth of the concentration needed to inhibit ACE2. All peptides studied evinced about equal inhibitory activities. CONCLUSION: To our knowledge the present findings constitute the first evidence of ACE2 activity in the ciliary and vitreous bodies, in addition to previously described activity in the retina. The known favorable effects of ACE2 products vs. those of ACE1 suggest a counterbalancing interaction of these two enzyme homologues in physiological regulation of ocular circulation and pressure and possible protective role in certain ophthalmic disorders such as glaucoma and diabetic retinopathy.
Authors: Galina D Kutuzova; B'ann T Gabelt; Julie A Kiland; Elizabeth A Hennes-Beann; Paul L Kaufman; Hector F DeLuca Journal: Arch Biochem Biophys Date: 2011-12-16 Impact factor: 4.013
Authors: Tiina Jauhiainen; Taru Pilvi; Zhong Jian Cheng; Hannu Kautiainen; Dominik N Müller; Heikki Vapaatalo; Riitta Korpela; Eero Mervaala Journal: J Nutr Metab Date: 2009-11-30
Authors: Giselle Foureaux; José C Nogueira; Bárbara S Nogueira; Gustavo O Fulgêncio; Gustavo B Menezes; Simone O A Fernandes; Valbert N Cardoso; Renata S Fernandes; Gabriel P Oliveira; Juçara R Franca; André A G Faraco; Mohan K Raizada; Anderson J Ferreira Journal: Invest Ophthalmol Vis Sci Date: 2013-06-21 Impact factor: 4.799
Authors: Amirhossein Roshanshad; Mohammad Ali Ashraf; Romina Roshanshad; Ali Kharmandar; Seyed Alireza Zomorodian; Hossein Ashraf Journal: J Ophthalmic Vis Res Date: 2021-04-29
Authors: Giselle Foureaux; Juçara Ribeiro Franca; José Carlos Nogueira; Gustavo de Oliveira Fulgêncio; Tatiana Gomes Ribeiro; Rachel Oliveira Castilho; Maria Irene Yoshida; Leonardo Lima Fuscaldi; Simone Odília Antunes Fernandes; Valbert Nascimento Cardoso; Sebastião Cronemberger; André Augusto Gomes Faraco; Anderson José Ferreira Journal: PLoS One Date: 2015-07-23 Impact factor: 3.240
Authors: G Foureaux; B S Nogueira; D C O Coutinho; M K Raizada; J C Nogueira; A J Ferreira Journal: Braz J Med Biol Res Date: 2015-09-29 Impact factor: 2.590