- A. Ludwig
- F. E. Isemer
- M. Kallerhoff
- K. W. Fuselage
Summary of the
An animal experimental autologous, heterotopic kidney transplantation model in dogs was chosen for the investigation of the change in renin activity and blood pressure after the onset of reblood of the transplant kidneys under HTK protection. The cold ischemia time was 48 hours. Due to modifications in the composition of the HTK perfusion solution, there were 3 experimental groups. In each experimental group, the renal venous and arterial renin concentration was determined over 20 min after the onset of recirculation of the graft kidney. The arterial blood pressure was measured parallel to the renin determination. The renin levels in the renal vein blood are highest in the first minutes after recirculation of the graft kidneys in the first experimental group (HTK solution, perfusion height 120 cm) of all collectives with a median value of the increase maxima of 195 ng/ml – h. The second experimental group (HTK/”aspartate” solution) shows a reduced median maximum renal venous renin concentration of 145 ng/ml – h with a more uniform curve. Of all the groups, the 3rd experimental group (HTK/”tryptophan” solution) showed the lowest maximum renin increases between 23.1 ng/ml-h and 120 ng/ml-h (median 61.5 ng/ml-h). After the 7.5th minute of observation, normal renal venous renin concentrations should be recorded. Thus, the best reperfusion of the kidney is detectable for the “tryptophan collective”, which, however, has no visible positive effect on further kidney function. Primarily low renin values therefore do not always correlate with good postoperative function and vice versa. From the initial renin values, a prediction value for immediate as well as long-term postoperative function cannot be derived. In all 3 experimental groups the measured renal venous renin values are associated with hypertonic arterial blood pressure values of 150-230 mm Hg. Renal venous renin concentrations >
100 ng/ml-h do not cause further blood pressure increases. Whether there is a fixed relationship between the renin values and hypertension must also remain questionable in our investigations. The different protection approaches apparently have no influence on the primary postoperative blood pressure conditions.
Supported by the German Research Foundation -SFB 330 Organ Protection Göttingen
Posthumously dedicated to Prof. Dr. med. Dr. h.c. H.J. Bretschneider
Changes in activity of renin and blood pressure in a canine autologous model of kidney transplantation using modified HTK solution
Investigations of changes in activity of renin and blood pressure after reperfusion of the kidney transplant using HTK solution were carried out by means of an autologous, heterotopic model of kidney transplantation applied to dogs. Duration of cold ischemia was 48 h. According to variations in the composition of the HTK perfusion solution three test groups were set up. During the first 20 min after recirculation in each test group the renal venous and arterial renin activities were measured. Parallel to renin activity, the arterial blood pressure was recorded. During the first few minutes following recirculation of the kidney transplant the renin levels in the venous blood of the kidney were higher in test group 1 (HTK solution, perfusion height 120 cm) than in either of the other two, showing a median maximal increase of 195 ng/ml · h. In test group 2 the maximal venous renin concentration fell to 145 ng/ml · h, while graphs take a more uniform course. Test group 3 (HTK/tryptophan) differed from the others in having further improved renin values. After the 7.5 min of observation normal venous renin concentrations were measured following earlier values for maximal increase between 23.1 ng/ml · h and 120 ng/ml · h (median 61.5 ng/ml · h). The best reperfusion of the kidney was observed in the tryptophan group, albeit without any recognizable positive effects on the other renal functions. Initially low renin values do not necessarily correlate with a smooth postoperative renal function and vice versa. Initial renin values cannot provide a secure basis for predicting instant as well as long-term postoperative functions. In all three test groups the measured renal venous activity of renin correlated with hypertonic basal pressure. Renal venous renin concentrations of > 100 ng/ml · h did not cause any further increase in blood pressure. The question as to whether there is a correlative dependence of renin values and hypertension is not clearly answered by our investigations. The variations in protection do not influence the primary postoperative blood pressure results.