Premium
Postischaemic regional microvascular variations in the porcine renal cortex
Author(s) -
Sandin R.,
Feuk U.,
Modig J.
Publication year - 1991
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1991.tb03332.x
Subject(s) - medicine , renal cortex , cortex (anatomy) , kidney , ischemia , blood flow , microcirculation , renal circulation , renal artery , renal blood flow , cardiology , biology , neuroscience
Regional microcirculatory differences in the superficial renal cortex were studied before and during 4 h following 60 min of renal ischaemia in seven pigs under continuous intravenous chlormethiazole‐pancuronium anaesthesia. Superficial renal cortical blood flow (Q src ) was measured by laser Doppler flowmetry (LDF) in two different regions. In two other different regions tissue oxygenation (Pto 2 ) was measured by surface electrodes. Thus, microcirculatory measurements were simultaneously carried out in each animal in four different regions of the left kidney. After 60 min of renal ischaemia, pronounced renal cortical microcirculatory disturbances were found. The regional microcirculatory differences were notable, especially after ischaemia. On average, Q src was 49 ± 11 (s.d.) arbitrary units at baseline and decreased to 24 ± 4 arb. units 4 h after start of reperfusion ( P <0.05). Before ischaemia the average difference between Q src simultaneously measured in two different parts of the renal cortex was 26 ± 15% of the mean of both measurements, and it was 30 ± 22% 4 h after start of reperfusion (n.s.). Mean Pto 2 (m‐Pto 2 ) was on average 4.5 ± 1.3 kPa at baseline and 2.4 ± 1.5 kPa 4 h after start of reperfusion ( P <0.05). The average difference between m‐Pto 2 simultaneously measured in two different parts of the renal cortex at baseline was 24 ± 13% of the mean of both measurements and 57 ± 49% 4 h after start of reperfusion (n.s.). In each of the two measured regions of the renal cortex m‐Pto 2 was calculated from 160 small tissue volumes distributed within a surface area of about 1 mm 2 . The percentage of these 160 measurements which exhibited Pto 2 <0.6 kPa (L‐Pto 2 ) was, on average, 1 ± 2% at baseline and increased to 19 ± 25% 4 h after start of reperfusion ( P <0.05). The average difference in L‐Pto 2 between the two measured regions was 1 ± 3% at baseline and 17 ± 21% 4 h after start of reperfusion (n.s.). The microcirculatory disturbances after ischaemia were strongly dependent on the elapsed time after start of reperfusion. Thus, measurements by techniques allowing continuous or repeated recordings are advantageous. Due to regional variability, Pto 2 and LDF measurements from several animals or from multiple regions in the renal cortex must be considered in order adequately to describe the postischaemic renal cortical microcirculation.