Three-dimensional Reconstruction Of Renal Sympathetic Nerve And Assessing Its Histological And Functional Remodeling In Hypertensive Canine Model And Human

PART Ⅰ HISTOLOGICAL AND FUNCTIONAL REMODELING OFRENAL SYMPATHETIC NERVE IN HYPERTENSIVECANINE MODELObjectives: The purpose of this part was to identify,in two-dimensional levels,whether renal sympathetic nerve(RSN)had histological and functional remodeling in hypertensive canine model.Methods: Canines were assigned to hypertension group(n=7)or non-hypertension group(n=7)according to the results of blood pressure(BP)measurement with invasive artery catheter.Left renal arteries were averagely divided into proximal,middle and distal segments.The histological and functional features of RSN and aorticorenal ganglion were investigated by hematoxylin-eosin staining and immunohistochemical(IHC)staining with anti-tyrosine hydroxylase(TH),anti-substance P or anti-growth associated protein-43(GAP 43)antibodies.We also assessed the norepinephrine(NE)concentration in renal tissue using high performance liquid chromatography(HPLC)analysis.Results: The mean BP was significantly higher in hypertension group(175.7±8.5/116.0±9.1 mm Hg)than in non-hypertension group(124.1±9.8/85.4±5.1 mm Hg,P<0.01).The number of RSN in proximal segment was increased in hypertension canines(P=0.042),but not in middle(P=0.417)and distal segments(P=0.641).In all segments,there was no significant difference in RSN size and distance from RSN to the lumen of renal artery between hypertension and non-hypertension groups.Results from IHC and HPLC analyses indicated that the mean density of TH(P=0.025)as well as substance P(P<0.01)and NE concentration in renal tissue were statistically augmented in hypertension canines.The mean area of neurons(P=0.023)and density of GAP 43(P=0.012)in aorticorenal ganglion were greater in hypertension group,but the mean neuron number(P=0.21)and density of TH(P=0.156)were similar between the two groups.Conclusions: Our study suggests that aorticorenal ganglion may have histological and functional remodeling and the function of afferent and efferent nerve fibers of RSN is also likely to be increased in hypertension canines.But whether RSN has histological remodeling in hypertension is needed to be investigated in the future.PART Ⅱ THREE-DIMENSIONAL RECONSTRUCTION OF RENALSYMPATHETIC NERVE IN HYPERTENSION ANDNON-HYPERTENSION CANINE MODELSObjectives: In this part,we aimed to reconstruct canine renal sympathetic nerve(RSN)with pathological three-dimensional reconstruction(PTDR)technology and investigate the RSN anatomical characteristics as well as histological remodeling of RSN in hypertension canines.Methods: Woman hair was penetrated into adipose tissue around the right canine renal artery as reference point.We performed intermittent serial frozen section and hematoxylin-eosin(HE)staining for the pretreated renal arteries.HE images were acquired with high definition scanner and matched consecutively using Photoshop software.The matched images were imported into 3D-doctor software and the reconstruction parameters were set according to the size of image.Then,we segmented boundaries for different tissue objects and three-dimensionally reconstructed the RSN using complex surface model.Finally,with the use of 3D-doctor software,the three-dimensional image of RSN was averagely divided into proximal,middle and distal segments and the data,including RSN volume,RSN number,RSN distance and so on,were measured automatically or manually.Results: We successfully reconstructed three-dimensional image of RSN with 3D-doctor software.Generally,most canine RSNs were originated solely from the superior of renal artery and accompanied it to the distal segment.The RSN volume in proximal was greater than that of middle(P<0.01)and distal(P<0.01)segments.The RSN number was more in superior(P<0.01)than in inferior,ventral and dorsal,but this difference was not observed in proximal,middle and distal.Distance from RSN to the lumen of renal artery was gradually decreased from proximal to distal(P<0.01).Compared with non-hypertension group,the RSN number was likely to be increased in hypertension group(P=0.02).However,there was no significant difference in RSN distance(P=0.054),mean RSN volume(P=0.12)and mean RSN/renal artery ratio(P=0.44)between hypertension and non-hypertension groups.Conclusions: We firstly reconstruct the three-dimensional image of canine RSN and detailed describe its anatomical characteristics in three-dimensional level.In addition,greater RSN number in hypertensive canines may indicate that hypertension may result in histological remodeling of RSN.PART Ⅲ THREE-DIMENSIONAL RECONSTRUCTION OF RENALSYMPATHETIC NERVE AND ASSESSING ITS HISTOLOGICAL AND FUNCTIONAL REMODELING INHUMANObjectives: The aim of this part was to three-dimensionally reconstruct human renal sympathetic nerve(RSN)and evaluate its anatomical features on the basis of three-dimensionally images.Moreover,by means of three-dimensionally images and immunohistochemical(IHC)staining,we also intended to identify whether human RSN and renal ganglion(RG)had histological and functional remodeling in hypertension patients.Methods: We conducted intermittent serial frozen section for human renal artery,and reconstructed the image of human RSN with pathological three-dimensional reconstruction(PTDR)technology.Data,including RSN and RG volume,RSN/renal artery and RG/renal artery volume ratio,maximum and minimum distance from RSN to lumen of renal artery,were measured automatically or manually.We also performed IHC staining with anti-tyrosine hydroxylase(TH),anti-substance P or anti-growth associated protein-43(GAP 43)antibodies on the frozen slices of RSN or RG.Finally,the medical history of included patients was obtained from the Department of Forensic Medicine of Chongqing Medical University.Results: A total of 11 renal arteries from 7 autopsy subjects(hypertension,n=4;non-hypertension,n=3)were included.Based on the three-dimensional images,human RSN was distributed along renal artery with a network manner.The RSN volume and RSN/renal artery volume ratio were greater in proximal than in middle and distal segments.The RG volume and RG/renal artery volume ratio of proximal and middle was also greater than that of distal.Distance from RSN to the lumen of renal artery was gradually decreased from proximal to distal.RSN volume in hypertension patients was similar with non-hypertension patients(P=0.072),but significant difference in RSN/renal artery volume ratio was observed(P=0.01)between two groups.Both RG volume(P=0.029)and RG/renal artery volume ratio(P=0.045)were statistically increased in hypertension group.Results for IHC analysis demonstrated that mean TH density of RSN were significantly augmented in hypertension patients(P<0.01),but mean density of substance P was similar(P=0.80).Moreover,the mean area of neuron(P<0.01)and mean density of GAP43(P<0.01)were also obviously increased in hypertension patients.Conclusions: Human RSN and RG are greater but further from renal artery in proximal than in distal,hence it may improve the effectiveness of RDN to choose the distal segment as the ablation target.In addition,in hypertension individuals,the elevation of RSN efferent nerve fibers and RG function and the increase of RG volume suggest that RG and RSN may have histological and functional remodeling in hypertension patients.