Thecomplicationsfrequentlyaccompanyingdiabetes，suchasimpairmentofvisionandofkidneyfunction，arenowthoughttoresultfromthelackofcontinuouscontrolofbloodglucoseconcentrations。Thehealthypancreas，inresponsetoincreasesinbloodglucoseconcentration，releasessmallquantitiesofinsulinthroughoutthedayandtherebymaintainstheconcentrationwithinphysiologicallimits。Butthediabeticgenerallyreceivesonlyonelargedosedaily。Thediabetic‘sbloodglucoseconcentrationcanthusfluctuategreatlyduringtheintervalbetweendoses，andithasbeensuggestedthatthecomplicationresultfromtheperiodsofhighconcentrationsofbloodglucose。Manyinvestigatorsthusbelievethatrestorationofnormoglycemiamighthalttheprogressionofsuchcomplicationsandperhapsevenreversethem。

Therearethreeprimarytechniquesthathavebeeninvestigatedforrestorationofnormoglycemia。Theyare：transplantationofwhole，healthypancreases;transplantationofisletsofLangerthan，thatportionofthepancreasthatactuallysecretesinsulin，andimplantationofartificialpancreases。Therehas，infactbeenagreatdealofsuccessinthedevelopmentofthesetechniquesandeachseems，onthewhole，promising。Nonetheless，itwillundoubtedlybemanyyearsbeforeanyoneofthemisacceptedasatreatmentfordiabetes。

Tomanypeople，theobviousapproachwouldseemtobesimplytotransplantpancreasesfromcadaversinthesamemannerthatkidneysandotherorgansareroutinelytransplanted。Thatwastherationalein1966whenthefirstrecordedpancreaswasperformed。Between1960and1975，therewereforty－sixpancreastransplantsinforty－fiveotherpatientsintheUnitedStatesandfiveothercountries。Butonlyoneofthesepatientsisstillalivewithafunctioninggraftandsurgeonshavefoundthattheprocedureisnotsimpleastheyoncethought。

Thesurvivingpatienthasrequirednoinsulinsincetheoperation。Anotherpatientsurvived638dayswithoutrequiringinsulin。Andonepatientsurvivedatransplantationformorethanayear，butdiedwhenhechosenottotakeimmunosuppressivedrugs。Theseresults，thoughmeager，suggestthattheprocedurehasthepotentialforsuccess。

Therestofthepatients，however，eitherrejectedthetransplantordiedwithinashortperiod。Theredoesnotappeartobeanytechnicalproblemwiththeprocedure。Rather，mostofthepatientswerealreadysoseverelydebilitatedbythecomplicationsofdiabetesthattheycouldnotwithstandthesurgeryandtheimmunosuppressiveregimenrequiredtopreventrejection。Morethanhalfofthepatients，furthermore，alsorequiredakidneytransplant。Mostinvestigatorsnowagreethatthesimultaneoustransplantationofbothorgansistoogreatashocktothepatientandgreatlyincreasesthetotalrisk。