Microstructural Characterization of Resistance Artery Remodelling in Diabetes Mellitus.

INTRODUCTION: Microvascular remodelling is a symptom of cardiovascular disease. Despite the mechanical environment being recognized as a major contributor to the remodelling process, it is currently only understood in a rudimentary way. OBJECTIVE: A morphological and mechanical evaluation of the resistance vasculature in health and diabetes mellitus. METHODS: The cells and extracellular matrix of human subcutaneous resistance arteries from abdominal fat biopsies were imaged using two-photon fluorescence and second harmonic generation at varying transmural pressure. The results informed a two-layer mechanical model. RESULTS: Diabetic resistance arteries reduced in wall area as pressure was increased. This was attributed to the presence of thick, straight collagen fibre bundles that braced the outer wall. The abnormal mechanical environment caused the internal elastic lamina and endothelial and vascular smooth muscle cell arrangements to twist. CONCLUSIONS: Our results suggest diabetic microvascular remodelling is likely to be stress-driven, comprising at least 2 stages: (1) Laying down of adventitial bracing fibres that limit outward distension, and (2) Deposition of additional collagen in the media, likely due to the significantly altered mechanical environment. This work represents a step towards elucidating the local stress environment of cells, which is crucial to build accurate models of mechanotransduction in disease.

Delayed two steps PRP injection strategy for the improvement of fat graft survival with superior angiogenesis.

Platelet-rich plasma (PRP) has been widely used to improve the fat retention rate in autologous fat transplantation since it possesses a good angiogenesis capability in vivo. However, due to the short half-life of growth factors released from PRP and its uneven distribution in injected fat tissue, the strategy of PRP in fat transplantation needs further improvement. Since the capillaries started to grow into fat grafts in 1 week and vascular growth peaks in the second week after transplantation, we hypothesized that delayed two-steps PRP injection into the interior of grafts, accompanied with the extent of neovascularization might theoretically promote microvessel growth inside transplanted adipose tissue. 24 nude mice were divided into three groups: Blank group (0.35 mL fat mixed with 0.15 mL saline, N = 8), Single step group (0.35 mL fat mixed with 0.15 mLPRP, N = 8), and Two steps group (0.35 mL fat (day 0) + 0.075 mL PRP (day 7) + 0.075 mL PRP (day 14), N = 8). At 6 and 14 weeks post-transplantation, grafts were dissected, weighted, and assessed for histology, angiogenesis, fat regeneration and inflammation level. The weight and volume of the fat samples revealed no statistical difference among the three groups at 6 weeks after fat transplantation. The weight and volume of the Two steps group fat samples showed significantly higher compared to that in Blank and Single step groups at 14 weeks after fat transplantation (weight: 137.25 ± 5.60 mg versus 87.5 ± 3.90 mg,106.75 ± 2.94 mg, respectively; volume: 0.13 ± 0.01 mL versus 0.08 ± 0.01 mL, 0.09 ± 0.01 mL, respectively). Histological assessments indicated that delayed two-steps PRP injection strategy helps to improve adipose tissue content and reduce the composition of fibrous connective tissue at 14 weeks after fat transplantation. At 6 weeks and 14 weeks after transplantation, CD31 immunofluorescence indicated that delayed two-steps PRP injection strategy helps to improve angiogenesis and significantly higher compared to that in Blank and Single step groups (6 weeks: 28.75 ± 4.54 versus 10.50 ± 2.06, 21.75 ± 1.85; 14 weeks: 21.75 ± 2.86 versus 9.87 ± 2.08, 11.75 ± 1.47, respectively). Preadipocyte count indicated delayed two-steps PRP injection strategy might promote fat regeneration and significantly higher compared to that in Blank and Single step groups at 14 weeks (129.75 ± 6.57 versus 13.50 ± 3.50, 17.12 ± 6.23, respectively). In this study, we demonstrated that the novel delayed two-steps PRP injection strategy remarkably enhanced the long-term fat retention rate and improved the neovascularization extent in the interior of the fat graft. Platelet-rich plasma, Delayed two-steps injection, Angiogenesis, Fat transplantation.

The importance of endothelial dysfunction in resistance artery remodelling and cardiovascular risk.

AIMS: The relationship between resistance artery remodelling and endothelial function remains unknown. In this study, we assessed (i) the capacity of endothelial function and nitric oxide (NO) availability to provide more information on the severity of resistance artery remodelling than common cardiovascular risk factors in subjects at low or high cardiovascular risk; and (ii) differences between patterns of resistance artery remodelling associated with deficit of NO availability and with exposure to cardiovascular risk factors. METHODS AND RESULTS: All analyses were conducted on the microvascular data set of the Italian Society for Arterial Hypertension (SIIA) that includes 356 patients with measures of small resistance arteries remodelling acquired with pressure or wire myography. Information on endothelial function and NO availability were also available in 116 patients. The European Heart Score (HS) was used to define the total cardiovascular risk of each patient. Endothelial function was inversely related with the severity of the resistance artery remodelling, and this association remained significant after adjustment for the HS. By contrast, the HS lost its significant association with the media-to-lumen (M/L) ratio and the media cross-sectional area after adjustment for endothelial function. The strength of these associations was similar in subjects at high and low cardiovascular risk. The addition of endothelial function and NO availability to the HS significantly improved the identification of subjects at more and less severe resistance artery remodelling. A severe deficit of NO availability was associated with hypertrophic remodelling, while a higher HS was more clearly associated with eutrophic remodelling. CONCLUSION: Resistance artery endothelial function and NO availability might represent important factors involved in resistance artery remodelling, independently from cardiovascular risk factor exposure.

Visualization of the fat planes between the pancreas and the adjacent organs and blood vessels using multi-detector computed tomography.

PURPOSE: To explore individual variations in visibility of the fat planes between the pancreatic parenchyma and adjacent organs and blood vessels using the multi-detector-computed tomography (MDCT). METHODS: Abdominal contrast-enhanced MDCT examinations of 520 consecutive adult individuals were retrospectively analysed by exploring the presence of visible fat planes between the healthy pancreas and the following surrounding structures: stomach, descending duodenum (D2), splenic, portal, superior mesenteric vein (SV, PV, SMV), inferior vena cava (IVC), and coeliac trunk, common hepatic and superior mesenteric artery (CT, HA and SMA). Spearman's rank correlation coefficient (rS) was used to assess the correlation of individual gender, age, body mass and BMI, and visible fat planes towards particular surrounding structures. RESULTS: Fat planes between the pancreatic parenchyma and surrounding structures was visible as follows: stomach in 76%, D2 11.7%, SV 51.5%, PV 0%, SMV 28.8%, IVC 80.8%, CT 99.4%, HA 90.4% and SMA in 100% participants. The presence of visible fat planes significantly correlated (p < 0.001) with body mass for stomach (rS = 0.367), D2 (rS = 0.247), SV (rS = 0.355), SMV (rS = 0.384) and IVC (rS = 0.259); BMI for stomach (rS = 0.292), SV (rS = 0.248), SMV (rS = 0.290) and IVC (rS = 0.216); age for D2 (rS = 0.363), SV (rS = 0.276) and SMV (rS = 0.409); and male gender for stomach (rS = 0.160) and SV (rS = 0.198). CONCLUSION: Fat planes around the pancreatic parenchyma in the MDCT scan was almost always visible towards the adjacent magistral visceral arteries and IVC, always invisible towards the PV, and variably visible towards the SV, SMV, stomach and duodenum depending on the individual body mass, BMI, age and gender.

Senescence Alters PPARγ (Peroxisome Proliferator-Activated Receptor Gamma)-Dependent Fatty Acid Handling in Human Adipose Tissue Microvascular Endothelial Cells and Favors Inflammation.

OBJECTIVE: Adipose tissue (AT) dysfunction associated with obesity or aging is a major cause for lipid redistribution and the progression of cardiometabolic disorders. Our goal is to decipher the contribution of human AT microvascular endothelial cells (ECs) in the maintenance of fatty acid (FA) fluxes and the impact of senescence on their function. APPROACH AND RESULTS: We used freshly isolated primary microvascular ECs from human AT. Our data identified the endothelial FA handling machinery including FATPs (FA transport proteins) FATP1, FATP3, FATP4, and CD36 as well as FABP4 (FA binding protein 4). We showed that PPARγ (peroxisome proliferator-activated receptor gamma) regulates the expression of FATP1, CD36, and FABP4 and is a major regulator of FA uptake in human AT EC (hATEC). We provided evidence that endothelial PPARγ activity is modulated by senescence. Indeed, the positive regulation of FA transport by PPARγ agonist was abolished, whereas the emergence of an inflammatory response was favored in senescent hATEC. This was associated with the retention of nuclear FOXO1 (forkhead box protein O1), whereas nuclear PPARγ translocation was impaired. CONCLUSIONS: These data support the notion that PPARγ is a key regulator of primary hATEC function including FA handling and inflammatory response. However, the outcome of PPARγ activation is modulated by senescence, a phenomenon that may impact the ability of hATEC to properly respond to and handle lipid fluxes. Finally, our work highlights the role of hATEC in the regulation of FA fluxes and reveals that dysfunction of these cells with accelerated aging is likely to participate to AT dysfunction and the redistribution of lipids.

Fatty Acids Have Different Adipogenic Differentiation Potentials in Stromal Vascular Cells Isolated from Abdominal Fat in Laying Hens.

This study was conducted to examine the effects of fatty acids (FA) with/without chicken serum (CS) on the expression of adipogenic transcripts and adipogenesis in chicken stromal vascular cells (SVC). In experiment 1, SVC were grown in DMEM containing 10% FBS (Control) and treated with 300 µM oleic acid (OLA) + FBS, linoleic acid (LNA) + FBS, palmitic acid (PAM) + FBS, or stearic acid (STA) + FBS for 48 h. In experiment 2, cells were grown in DMEM containing 5% CS and treated with 300 µM OLA (CS + OLA), PAM (CS + PAM), STA (CS + STA) or 200 µM LNA (CS + LNA) for 48 h. Adipogenesis was determined using Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity. The proportion of OLA, PAM, or STA was increased (P < 0.05) in SVC grown in either FBS or CS with OLA, PAM or STA. Adipogenesis was induced in FBS + OLA, FBS + LNA, FBS + PAM, FBS + STA, CS + OLA, CS + LNA, CS + PAM, or CS + SAT compared to FBS. GPDH activity was significantly higher in FBS + OLA and FBS + LNA than one in FBS. Compared to FBS, the expression of FABP4 mRNA increased (P < 0.05) in FBS + OLA, FBS + LNA, or FBS + PAM, whereas that of C/EBPα, C/EBPß, and ATGL increased (P < 0.05) in FBS + OLA or FBS + LNA cells. Expression of FABP4 and C/EBPß mRNA was higher in CS, CS + OLA, CS + LNA, CS + PAM, or CS + SAT compared with (FBS, whereas the expression of ATGL and C/EBPα was higher in CS, CS + OLA, or CS + LNA than FBS cells. In conclusion, these results showed that FA have different potentials to induce adipogenesis, LNA is the most potent among the tested FA, and these potentials can be improved in the presence of CS.

Observation of a Flowing Duct in the Abdominal Wall by Using Nanoparticles.

The primo vascular system (PVS) is being established as a circulatory system that corresponds to acupuncture meridians. There have been two critical questions in making the PVS accepted as a novel liquid flowing system. The first one was directly to show the flow of liquid in PVS and the second one was to explain why it was not observed in the conventional histological study of animal tissues. Flow in the PVS in the abdominal cavity was previously verified by injecting Alcian blue into a primo node. However, the tracing of the dye to other subsystems of the PVS has not been done. In the current work we injected fluorescent nanoparticles (FNPs) into a primo node and traced them along a primo vessel which was inside a fat tissue in the abdominal wall. Linea alba is a white middle line in the abdominal skin of a mammal and a band of fat tissue is located in parallel to the linea alba in the parietal side of the abdominal wall of a rat. In this fat band a primo vessel runs parallel to the prominent blood vessels in the fat band and is located just inside the parietal peritoneum. About the second question on the reason why the PVS was not in conventional histological study the current work provided the answer. Histological analysis with hematoxyline and eosine, Masson's trichrome, and Toluidine blue could not discriminate the primo vessel even when we knew the location of the PVS by the trace of the FNPs. This clearly explains why the PVS is hard to observe in conventional histology: it is not a matter of resolution but the contrast. The PVS has very similar structure to the connective tissues that surround the PVS. In the current work we propose a method to find the PVS: Observation of mast cell distribution with toluidine blue staining and the PN has a high density of mast cells, while the lymph node has low density.

Differential effects of aging and exercise on intra-abdominal adipose arteriolar function and blood flow regulation.

Adipose tissue (AT), which typically comprises an increased percentage of body mass with advancing age, receives a large proportion of resting cardiac output. During exercise, an old age-associated inability to increase vascular resistance within the intra-abdominal AT may compromise the ability of the cardiovascular system to redistribute blood flow to the active musculature, contributing to the decline in exercise capacity observed in this population. We tested the hypotheses that 1) there would be an elevated perfusion of AT during exercise with old age that was associated with diminished vasoconstrictor responses of adipose-resistance arteries, and 2) chronic exercise training would mitigate the age-associated alterations in AT blood flow and vascular function. Young (6 mo; n = 40) and old (24 mo; n = 28) male Fischer 344 rats were divided into young sedentary (YSed), old sedentary (OSed), young exercise trained (YET), or old exercise trained (OET) groups, where training consisted of 10-12 wk of treadmill exercise. In vivo blood flow at rest and during exercise and in vitro α-adrenergic and myogenic vasoconstrictor responses in resistance arteries from AT were measured in all groups. In response to exercise, there was a directionally opposite change in AT blood flow in the OSed group (≈ 150% increase) and YSed (≈ 55% decrease) vs. resting values. Both α-adrenergic and myogenic vasoconstriction were diminished in OSed vs. YSed AT-resistance arteries. Exercise training resulted in a similar AT hyperemic response between age groups during exercise (YET, 9.9 ± 0.5 ml · min(-1) · 100(-1) g; OET, 8.1 ± 0.9 ml · min(-1) · 100(-1) g) and was associated with enhanced myogenic and α-adrenergic vasoconstriction of AT-resistance arteries from the OET group relative to OSed. These results indicate that there is an inability to increase vascular resistance in AT during exercise with old age, due, in part, to a diminished vasoconstriction of AT arteries. Furthermore, the results indicate that exercise training can augment vasoconstriction of AT arteries and mitigate age-related alterations in the regulation of AT blood flow during exercise.

Omega-3 fatty acids reduce adipose tissue macrophages in human subjects with insulin resistance.

Fish oils (FOs) have anti-inflammatory effects and lower serum triglycerides. This study examined adipose and muscle inflammatory markers after treatment of humans with FOs and measured the effects of ω-3 fatty acids on adipocytes and macrophages in vitro. Insulin-resistant, nondiabetic subjects were treated with Omega-3-Acid Ethyl Esters (4 g/day) or placebo for 12 weeks. Plasma macrophage chemoattractant protein 1 (MCP-1) levels were reduced by FO, but the levels of other cytokines were unchanged. The adipose (but not muscle) of FO-treated subjects demonstrated a decrease in macrophages, a decrease in MCP-1, and an increase in capillaries, and subjects with the most macrophages demonstrated the greatest response to treatment. Adipose and muscle ω-3 fatty acid content increased after treatment; however, there was no change in insulin sensitivity or adiponectin. In vitro, M1-polarized macrophages expressed high levels of MCP-1. The addition of ω-3 fatty acids reduced MCP-1 expression with no effect on TNF-α. In addition, ω-3 fatty acids suppressed the upregulation of adipocyte MCP-1 that occurred when adipocytes were cocultured with macrophages. Thus, FO reduced adipose macrophages, increased capillaries, and reduced MCP-1 expression in insulin-resistant humans and in macrophages and adipocytes in vitro; however, there was no measureable effect on insulin sensitivity.

Adipose stem cells originate from perivascular cells.

Recent research has shown that adipose tissues contain abundant MSCs (mesenchymal stem cells). The origin and location of the adipose stem cells, however, remain unknown, presenting an obstacle to the further purification and study of these cells. In the present study, we aimed at investigating the origins of adipose stem cells. α-SMA (α-smooth muscle actin) is one of the markers of pericytes. We harvested ASCs (adipose stromal cells) from α-SMA-GFP (green fluorescent protein) transgenic mice and sorted them into GFP-positive and GFP-negative cells by FACS. Multilineage differentiation tests were applied to examine the pluripotent ability of the α-SMA-GFP-positive and -negative cells. Immunofluorescent staining for α-SMA and PDGF-Rß (platelet-derived growth factor receptor ß) were applied to identify the α-SMA-GFP-positive cells. Then α-SMA-GFP-positive cells were loaded on a collagen-fibronectin gel with endothelial cells to test their vascularization ability both in vitro and in vivo. Results show that, in adipose tissue, all of the α-SMA-GFP-positive cells congregate around the blood vessels. Only the α-SMA-GFP-positive cells have multilineage differentiation ability, while the α-SMA-GFP-negative cells can only differentiate in an adipogenic direction. The α-SMA-GFP-positive cells maintained expression of α-SMA during multilineage differentiation. The α-SMA-GFP-positive cells can promote the vascularization of endothelial cells in three-dimensional culture both in vitro and in vivo. We conclude that the adipose stem cells originate from perivascular cells and congregate around blood vessels.

Anatomic considerations in abdominoplasty.

Knowledge of abdominal anatomy is key to achieving optimal results in abdominoplasty. With adequate knowledge of the anatomy, the surgeon can tailor his or her techniques to fit the needs of the patient while still maximizing the blood supply to the abdominal flaps and minimizing complications.

Morphological characteristics of abdominal adipose tissue in normal-weight and obese women of different metabolic profiles.

BACKGROUND AND AIMS: Morphological changes in adipose tissue reflect functional disorders that correlate with cardiometabolic complications of obesity. The metabolic risks vary among the obese individuals. Furthermore, normal-weight individuals are not necessarily metabolically healthy. Therefore, the aim of this study was to analyze morphological characteristics of the abdominal adipose tissue in normal-weight and obese individuals in regards to metabolic risks. METHODS AND RESULTS: The study group consisted of 30 overweight or obese and 20 normal-weight women undergoing elective surgery. Women of each group were divided into metabolically healthy and metabolically obese, based on the homeostasis model assessment of insulin resistance (HOMA-IR), triglyceride, total-, LDL- and HDL-cholesterol levels. The size and numerical density of adipocytes, as well as volume density of blood vessels in subcutaneous and visceral adipose tissue were compared among subgroups. The results showed hypertrophy of adipocytes of visceral adipose tissue in metabolically obese normal-weight women. At the same time, metabolically healthy obese women had smaller adipocytes in both depots in comparison with "at risk" obese women. The lowest volume density of blood vessels correlated with the largest diameter of adipocytes in "at risk" obese women indicating hypoxic changes in visceral adipose tissue. The observed differences of the adipose tissue morphology did not correlate with considerable phenotypic differences within either the normal-weight or obese women group. CONCLUSION: Changes in adipocyte size, cellular and vascular density of adipose tissue in relation with metabolic disorders, regardless of nutritional level, suggest limited capacity of fat deposition and adipose tissue response to hypoxia.

The perforator angiosome: a new concept in the design of deep inferior epigastric artery perforator flaps for breast reconstruction.

BACKGROUND: The previously described "perfusion zones" of the abdominal wall vasculature are based on filling of the deep inferior epigastric artery (DIEA) and all its branches simultaneously. With the advent of the DIEA perforator flap, only a single or several perforators are included in supply to the flap. As such, a new model for abdominal wall perfusion has become necessary. The concept of a "perforator angiosome" is thus explored. METHODS: A clinical and cadaveric study of 155 abdominal walls was undertaken. This comprised the use of 10 whole, unembalmed cadaveric abdominal walls for angiographic studies, and 145 abdominal wall computed tomographic angiograms (CTAs) in patients undergoing preoperative imaging of the abdominal wall vasculature. The evaluation of the subcutaneous branching pattern and zone of perfusion of individual DIEA perforators was explored, particularly exploring differences between medial and lateral row perforators. RESULTS: Fundamental differences exist between medial row and lateral row perforators, with medial row perforators larger (1.3 mm vs. 1 mm) and more likely to ramify in the subcutaneous fat toward the contralateral hemiabdomen (98% of cases vs. 2% of cases). A model for the perfusion of the abdominal wall based on a single perforator is presented. CONCLUSION: The "perforator angiosome" is dependent on perforator location, and can mapped individually with the use of preoperative imaging.

Interstitial concentrations of adipokines in subcutaneous abdominal and femoral adipose tissue.

Adipokines play important regulatory roles in the pathophysiology of obesity and insulin resistance. We measured plasma and interstitial concentrations of the adipokines adiponectin, resistin, leptin, monocyte chemoattractant protein-1 (MCP-1), interleukin-6 (IL-6) and interleukin-8 (IL-8) in subcutaneous, abdominal and femoral adipose tissue using calibrated, large-pore microdialysis technique in 8 healthy, lean men on 2 experimental days. The interstitial leptin concentration was 2.5-fold higher in subcutaneous, femoral than abdominal adipose tissue (P<0.05), but no regional differences were found for the remaining adipokines (P>0.05). Adiponectin and leptin concentrations were higher in plasma than subcutaneous adipose tissue (approximately 25-fold and approximately 2-fold, respectively, P<0.05), whereas MCP-1, IL-6 and IL-8 concentrations were higher in subcutaneous adipose tissue than plasma (approximately 100-fold, approximately 200-fold and approximately 1000-fold, respectively, P<0.05). Resistin concentrations did not differ significantly between compartments. Adipose tissue blood flow (ATBF) showed no regional difference (P>0.05). The intra- and inter-subject variations of all investigated adipokines as well as of ATBF were substantial (coefficient of variation: 4-177%). In conclusion, interstitial leptin concentrations are approximately 2.5-fold higher in subcutaneous, femoral than abdominal adipose tissue, which might be a potential mechanism behind the health-benefits of "pear-shape". Furthermore, subcutaneous adipose tissue has a marked production of pro-inflammatory adipokines.

The role of the neuropeptide Y2 receptor in liporemodeling: neuropeptide Y-mediated adipogenesis and adipose graft maintenance.

BACKGROUND: Neuropeptide Y is a signaling molecule that was recently found to stimulate adipose tissue growth in vitro by means of a peripherally acting mechanism involving the neuropeptide Y2 receptor found on adipocytes and endothelial cells. This study aims to evaluate the translational applications of a neuropeptide Y2 receptor agonist for autologous fat grafting in plastic surgery. METHODS: Murine and primate animal models were used to investigate the proliferative effects of neuropeptide Y on adipose tissue. The effect of applying neuropeptide Y to subcutaneous tissues in mice and monkeys was assessed by magnetic resonance imaging, histology, and immunohistochemistry. The effect of neuropeptide Y on human fat xenograft survival and vascularity in athymic mice was measured by ultrasonography and immunohistochemistry. Six animals per group were used in murine experiments, and two animals were used in the pilot primate study. RESULTS: Neuropeptide Y stimulated growth of adipose tissues when applied subcutaneously in mice and monkeys, and increased human fat xenograft survival and vascularity in athymic mice at 3 months. CONCLUSIONS: These data provide in vivo evidence for a critical role for neuropeptide Y/neuropeptide Y2 receptor interactions in adipogenesis, and suggest neuropeptide Y2 receptor as a potential target for agonist compounds that can be used to enhance fat graft survival or stimulate de novo adipogenesis.

Effects of weight loss on visceral and abdominal subcutaneous adipose tissue blood-flow and insulin-mediated glucose uptake in healthy obese subjects.

OBJECTIVE: Rapid weight loss with very-low-calorie diet (VLCD) is known to improve insulin sensitivity and decrease adipose tissue masses. The aim was to investigate the effects of VLCD on adipose tissue regional glucose uptake (rGU) and perfusion and their association with adipokines. RESEARCH DESIGN AND METHODS: Sixteen healthy obese (body mass index 33+/-1.1 kg/m(2)) subjects underwent VLCD for 6 weeks. RGU and perfusion were measured using [(18)F]-fluoro-deoxy-glucose, [(15)O]H(2)O and positron emission tomography. RESULTS: Blood-flow and rGU expressed per gram of adipose tissue were higher in visceral fat compared to abdominal subcutaneous fat (P<0.01 for both). Dieting decreased weight by 11+/-0.9 kg (P<0.0001). Visceral adipose fat decreased by 25% (P<0.001) and abdominal subcutaneous fat by 16% (P<0.001). Whole body insulin sensitivity increased by 33% (P<0.01). Perfusion of both fat depots decreased (P<0.001), while rGU remained unchanged. Among the adipokines, leptin and interleukin-6 levels seemed to be associated with abdominal subcutaneous and intra-abdominal adipose tissue insulin resistance but not with adipose tissue perfusion. CONCLUSIONS: Abdominal adipose tissue perfusion and rGU are not related in obesity. Rapid weight loss decreases perfusion through adipose tissue depots but has no influence on rGU demonstrating the 'sink' role of adipose tissue.

The abdominal adipofascial flap: a new model for direct in vivo observation of microcirculatory hemodynamics of the abdominal fat tissue in rat.

INTRODUCTION: The peripheral adipose tissue is a vital component of many procedures in reconstructive and esthetic surgery. There is a limited knowledge on hemodynamic changes of adipose tissue. A direct intravital microscopic observation method is needed for the measurement of microcirculatory changes occurring in peripheral fat tissue during different plastic surgical procedures. Here we are introducing a model allowing for the direct in vivo monitoring and measurements of microcirculatory hemodynamics of peripheral adipose tissue. METHODS: Eight male Lewis rats weighing between 150 and 180 g were used in this study. Eight abdominal adipofascial flaps based on the left femoral artery, vein, and nerve were dissected after excision of the skin of the groin and lower abdominal region. Flap angiography using Indian ink was performed to demonstrate vascular anatomy of the flap. Standard intravital microscopy was used to monitor hemodynamic parameters such as vascular diameters, functional capillary perfusion, and leukocyte-endothelial interactions. RESULTS: Under direct intravital microscopy, microcirculatory parameters including vascular diameters, capillary perfusion, and leukocyte-endothelial interaction behaviors of the abdominal adipofascial flaps were established. CONCLUSIONS: We have showed feasibility of monitoring microcirculatory hemodynamics of the abdominal adipofascial flap model in rat. This model can be applied for intravital recordings of peripheral adipose tissue physiology and in different research scenarios such as the effects of ischemia reperfusion injury, effects of surgical trauma and wound healing studies with application of different pharmacologic agents and treatment protocols.