the problem is consequently that of being able to prevent , reduce or minimize said ischemia / reperfusion injuries by implementing protection of the biological material , in particular of an organ or tissues , which is as effective as possible . the solution of the invention is a gas composition comprising argon as active gas compound chosen for use in preventing or minimizing an ischemia / reperfusion injury to a biological material in a recipient individual , during and / or following the transplantation of said biological material in said recipient individual , said gas composition being administered to the recipient individual prior to , during and / or following the surgical operation targeted at grafting the biological material in said recipient individual . as the case may be , the gas composition of the invention can comprise one or more of the following technical characteristics : the biological material is an organ , it comprises between 15 and 80 % by volume of said active gas compound , that is to say of argon , the biological material is a tissue , an organ or cells , the biological material is an organ chosen from the liver , kidneys , lungs and heart , the active gas compound is mixed with a gas comprising oxygen , prior to its administration to the recipient individual , the recipient individual is a human being , that is to say a man , a woman , a child , a newborn , and the like , it is administered in the gaseous form by inhalation , it additionally comprises at least one additional active gas compound chosen from n 2 , xe , h 2 , he , h 2 s , kr , ne , no and co , it optionally comprises oxygen , it is composed of argon and of oxygen for the remainder , that is to say an ar / o 2 gas mixture , it is in the gaseous form and is administered by inhalation using a breathing mask or an intubation probe , it comprises at least 20 % by volume of said active gas compound , it comprises at most 60 % by volume of said active gas compound . more generally , in the context of the present invention , it has been demonstrated that , in order to reduce damage or injuries resulting from ischemias / reperfusions in organs or other biological tissues withdrawn from a donor individual and intended to be reimplanted and grafted in a recipient individual , it is advisable to act , prior to , during and / or after the surgical operation targeted at grafting said organs or biological tissues in the body of the recipient , by administering a protective gas composition based on argon to the recipient . in other words , a gas composition comprising a gas such as argon as a mixture with oxygen can be used in a therapeutic treatment method targeted at preventing or at minimizing an ischemia / reperfusion injury to a biological material in a recipient individual , such as a human being , during and / or following the transplantation of said biological material in said recipient individual , in which said gas composition is administered to the recipient individual prior to , during and / or following the surgical operation targeted at grafting the biological material in said recipient individual . in addition , the invention relates to the use of argon for manufacturing a gas composition comprising argon as active gas compound for use in preventing or minimizing an ischemia / reperfusion injury to a biological material in a recipient individual , during and / or following the transplantation of said biological material in said recipient individual , said gas composition being administered to the recipient individual prior to , during and / or following the surgical operation targeted at grafting the biological material in said recipient individual . the duration of administration of the gas can be easily determined on the basis of the duration of the anesthesia , via simple routine tests , as a function of the organ to be implanted and of the recipient individual considered . in order to show the effectiveness of a gas composition according to the invention formed of a gas mixture of argon and of oxygen in preventing or minimizing ischemia / reperfusion injuries to a biological material in a recipient individual , use is made of an animal model which makes it possible to demonstrate the effect of the administration of the gas , during and / or following the transplantation of said biological material in the recipient . in this instance , the animals which are used for the tests are pigs and mice , anesthetized and intubated / ventilated , and the biological material is the lung . in order to do this , a virtual withdrawal of the lungs from the animals is carried out by clamping said lungs , arteries and veins connected to the lungs so as to obtain complete exclusion of the lungs from the bodies of the test animals in a way identical to a real extraction . once clamping has been carried out , there is a wait for a period of approximately 90 minutes and then the lungs , veins and arteries are declamped . the lungs of the animals are then ventilated for 4 hours with the test gas compositions . the test composition ( ar / o 2 ) comprises contents of ar of between 15 and 80 % by volume , the remainder being oxygen . a group of control animals is treated in the same way but with gas mixtures of nitrogen and of oxygen ( n 2 / o 2 ) in the same proportions . the gas compositions are administered to the animals by inhalation , the animals being intubated and supplied with gas by a respiratory ventilator . the animals are then sacrificed and the lungs are extracted and subjected to anatomical studies in order to determine the ischemic state , that is to say the presence of possible injuries due to the ischemia / reperfusion period . the results obtained show that the compositions according to the invention , based on argon , reduce ischemia / reperfusion injuries and their consequences on the satisfactory operation of the lungs , in contrast to the animals of the control group which have inhaled mixtures based on nitrogen . these tests show the advantage in administering a gas composition according to the invention to a recipient individual , prior to , during and / or following the surgical operation targeted at grafting a biological material in said recipient individual , in particular an organ .