A pharmaceutical composition for use in a method of treatment of a cardiovascular disorder wherein mitochondrial function in a target tissue or cell is impaired, wherein the pharmaceutical composition is a preparation comprising a subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source, wherein the preparation is made by a method comprising: (a) providing a tissue source of mitochondria; (b) dissociating the tissue source to produce a subcellular composition; (c) separating the subcellular composition into a cellular debris fraction and an enriched fraction, which is enriched for subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source, wherein the cellular debris fraction is a solid or pelleted fraction and the enriched fraction is a fluid fraction; (d) separating the enriched fraction into a fraction containing the subcellular apparatus and a fraction substantially lacking subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source, wherein the fraction containing the subcellular apparatus is a solid or pellet fraction and the fraction lacking the subcellular apparatus is a supernatant; and (e) suspending the fraction containing the subcellular apparatus in a solution, thereby preparing a preparation comprising a subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source; wherein the subcellular apparatus of the preparation have a mean size of between 175-950 nm, and wherein: (i) the dissociating comprises applying to the tissue source a first shear force followed by a second, higher shear force, wherein the first shear force is applied by douncing; and (ii) both of the separating steps (c) and (d) comprise differential centrifugation; or wherein both of the separating steps (c) and (d) comprise differential size filtration; and (iii) the subcellular apparatus of the preparation have a membrane potential that is between -5 to -200 mV, and wherein the subcellular apparatus are derived from mitochondria. (a) providing a tissue source of mitochondria; (b) dissociating the tissue source to produce a subcellular composition; (c) separating the subcellular composition into a cellular debris fraction and an enriched fraction, which is enriched for subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source, wherein the cellular debris fraction is a solid or pelleted fraction and the enriched fraction is a fluid fraction; (d) separating the enriched fraction into a fraction containing the subcellular apparatus and a fraction substantially lacking subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source, wherein the fraction containing the subcellular apparatus is a solid or pellet fraction and the fraction lacking the subcellular apparatus is a supernatant; and (e) suspending the fraction containing the subcellular apparatus in a solution, thereby preparing a preparation comprising a subcellular apparatus derived and isolated or purified from a mitochondrial network of a tissue source; wherein the subcellular apparatus of the preparation have a mean size of between 175-950 nm, and wherein: (i) the dissociating comprises applying to the tissue source a first shear force followed by a second, higher shear force, wherein the first shear force is applied by douncing; and (ii) both of the separating steps (c) and (d) comprise differential centrifugation; or wherein both of the separating steps (c) and (d) comprise differential size filtration; and (iii) the subcellular apparatus of the preparation have a membrane potential that is between -5 to -200 mV, and wherein the subcellular apparatus are derived from mitochondria. (i) the dissociating comprises applying to the tissue source a first shear force followed by a second, higher shear force, wherein the first shear force is applied by douncing; and (ii) both of the separating steps (c) and (d) comprise differential centrifugation; or wherein both of the separating steps (c) and (d) comprise differential size filtration; and (iii) the subcellular apparatus of the preparation have a membrane potential that is between -5 to -200 mV, and