Reactant release arrangement for releasing reactant into the exhaust gas stream of an internal combustion engine, comprising: - an exhaust gas guide element (12; 12a; 12b) providing an exhaust gas flow duct (13; 13a; 13b), through which exhaust gas (G) can flow in a main exhaust gas flow direction (A); - a reactant release body (14; 14a, 14b) carried extending into the exhaust gas flow duct (13; 13a; 13b) along a longitudinal axis (K) of the body at the exhaust guide element (12; 12a; 12b) with a body wall (16; 16a; 16b), wherein a reactant-receiving volume (20; 20a; 20b) surrounded by a wall inner surface (32; 32a; 32b) of the body wall (16; 16a; 16b) is provided in the reactant release body (14; 14a; 14b), wherein the reactant-receiving volume (20; 20a; 20b) is configured tapering in a tapering direction (R) in the direction of the body longitudinal axis (K) in at least some areas and wherein exhaust gas (G) flowing in the exhaust gas flow duct (13; 13a; 13b) can flow around the reactant release body (14; 14a; 14b) at a wall outer surface (18; 18a; 18b) of the body wall (16; 16a; 16b), wherein the reactant-receiving volume (20; 20a; 20b) is open to the exhaust gas flow duct (13; 13a; 13b) via at least one passage opening (44;46; 62a, 64a; 44b, 46b), - a reactant release unit (22; 22a; 22b) for releasing reactant (M) into the reactant-releasing volume (20; 20a; 20b), wherein a heating device (38; 38a; 38b) for heating the reactant release body (14; 14a; 14b) is associated with the body wall (16; 16a; 16b) at least in the area of the wall inner surface (32; 32a; 32b) of the body wall (16; 16a; 16b), wherein the body wall (16; 16a; 16b) comprises an inner wall (30; 30a; 30b) at least partly providing the wall inner surface (32; 32a; 32b) and an outer wall (26; 26a; 26b) at least partly providing the wall outer surface (18; 18a; 18b), and wherein the heating device (38; 38a; 38b) is arranged between the inner wall (30; 30a; 30b) and the outer wall (26; 26a; 26b), characterized in that the heating device (38; 38a; 38b) is arranged at least in a length area (L 1 ; L) of the body wall (16; 16a; 16b) with a tapering reactant-receiving volume (20; 20a; 20b). - an exhaust gas guide element (12; 12a; 12b) providing an exhaust gas flow duct (13; 13a; 13b), through which exhaust gas (G) can flow in a main exhaust gas flow direction (A); - a reactant release body (14; 14a, 14b) carried extending into the exhaust gas flow duct (13; 13a; 13b) along a longitudinal axis (K) of the body at the exhaust guide element (12; 12a; 12b) with a body wall (16; 16a; 16b), wherein a reactant-receiving volume (20; 20a; 20b) surrounded by a wall inner surface (32; 32a; 32b) of the body wall (16; 16a; 16b) is provided in the reactant release body (14; 14a; 14b), wherein the reactant-receiving volume (20; 20a; 20b) is configured tapering in a tapering direction (R) in the direction of the body longitudinal axis (K) in at least some areas and wherein exhaust gas (G) flowing in the exhaust gas flow duct (13; 13a; 13b) can flow around the reactant release body (14; 14a; 14b) at a wall outer surface (18; 18a; 18b) of the body wall (16; 16a; 16b), wherein the reactant-receiving volume (20; 20a; 20b) is open to the exhaust gas flow duct (13; 13a; 13b) via at least one passage opening (44;46; 62a, 64a; 44b, 46b), - a reactant release unit (22; 22a; 22b) for releasing reactant (M) into the reactant-releasing volume (20; 20a; 20b), <EOS>