Depleted Calcium Stores and Increased Calcium Entry in Rod Photoreceptors of the Mouse Model of Cone-Rod Dystrophy RCD4.

Unidentified pathogenetic mechanisms and genetic and clinical heterogeneity represent critical factors hindering the development of treatments for inherited retinal dystrophies. Frameshift mutations in , which codes for an accessory subunit of voltage-gated calcium channels (VGCC), cause cone-rod dystrophy RCD4 in patients, but the underlying mechanisms remain unknown. To define its pathogenetic mechanisms, we investigated the impact of a frameshift mutation on the electrophysiological profile and calcium handling of mouse rod photoreceptors by patch-clamp recordings and calcium imaging, respectively.

Electrochemical characterization of ordered arrays of metallo-porphyrins in aqueous solution.

Metallated meso-tetrakis(N-methyl-4-pyridyl)porphyrin (MTMPyP) and 5,11,17,23-tetrasulfonato-25,26,27,28-tetrakis-(hydroxylcarbonylmethoxy)-calix[4]arene (C(4)TsTc) were used as key components for building up discrete supramolecular entities starting from the formation of the template species MTMPyP:C(4)TsTc (1 : 4, M = Cu, Zn). The stepwise addition of further amount of porphyrin allows the facile non-covalent synthesis of discrete supramolecular entities (2 : 4 and 3 : 4) which can be built up just by programming the right stoichiometric addition of the proper porphyrin. The redox potentials of these supramolecular complexes in aqueous media, as well as those of the parent metalloporphyrins, have been characterized by using square wave voltammetry technique.