Syringe comprising: - a body (2) comprising a substantially cylindrical side wall (3) having an open upstream end in the vicinity of which an inner annular weatherstrip (9) and a downstream end enclosed by a transverse wall ( 5) provided with a hole (6)； - a rod (10) forming a pusher, comprising at one end a piston (11) forming a seal which has at least two annular sealing lips (12, 13 , 14) among which at least one annular chamber (16, 17) is defined, said rod (10) being able to be inserted and paralyzed into the body (2)； then an inner chamber being intended to be at least partially filled with a defined content (18) between the piston (11) and the transverse wall (5) of the body (2)； characterized in that it further comprises passage means (21, 24, 27) practiced in the body (2) of Lajeringa (1) and willing to put in communication n said annular chamber or said annular chambers (16, 17) of the piston (11) with the outside of the body (2) or with the inner chamber of the body (2), when the piston (11) is located in the interior of the body (2 ) butt against the annular gasket (9).Jeringa que comprende:- un cuerpo (2) que comprende una pared lateral (3) sustancialmente cilíndrica que presenta un extremo aguasarriba abierto en la proximidad del cual está practicado un burlete (9) anular interior y un extremo aguas abajocerrado por una pared transversal (5) provista de un orificio (6)；- un vástago (10) que forma un empujador, que comprende en un extremo un pistón (11) que forma una junta deestanqueidad que posee por lo menos dos labios de estanqueidad anulares (12, 13, 14) entre los cuales estádefinida por lo menos una cámara anular (16, 17), siendo dicho vástago (10) apto para ser introducido y paradeslizar en el cuerpo (2)；estando entonces una cámara interior destinada a ser por lo menos parcialmente llenada con un contenido (18)definida entre el pistón (11) y la pared transversal (5) del cuerpo (2)；caracterizada porque comprende además unos medios de paso (21, 24,
