Purpose The purpose of this study was to determine if adventitial transplantation of human adipose derived mesenchymal stem cell (MSC) to the outflow vein of B6.Cg-Foxn1nu/J mice with AVF at the time of creation would reduce monocyte chemoattractant protein-1 (Mcp-1) gene expression and venous neointimal hyperplasia (VNH). The second aim was to track transplanted 89 zirconium (89Zr) labeled MSCs serially by positron emission tomography (PET) imaging for 21 days. Materials and Methods All animal experiments were performed according to protocols approved by our institutional animal care and use committee. We used fifty B6.Cg-Foxn1nu/J mice to accomplish the aims outlined in the current paper. 2.5 × 105 MSC cells were stably labeled with green fluorescent protein (GFP) and injected into the adventitia of the outflow vein at the time of AVF creation in MSC group. Eleven mice died after AVF placement. Animals were sacrificed at day 7 following AVF placement for real time polymerase chain reaction (qRT-PCR, n=6 for MSC and control groups) and histomorphometric analyses (n=6, n=6 for MSC and control groups) and at day 21 for histomorphometric analysis only (n=6 for MSC and control groups). In a separate group of experiments (n=3), transplanted 89zirconium (89Zr) labeled MSCs animals were serially imaged by PET imaging for 3 weeks. Multiple comparisons were performed with two-way ANOVA followed by Student t-test with post hoc Bonferroni’s correction. Results We observed that in MSC transplanted vessels when compared to control vessels, there was a significant decrease in the Mcp-1 gene expression (day 7: average reduction: 62%, P=0.029) with a significant increase in the average lumen vessel area (day 7: average increase: 176%, P=0.013; day 21: average increase: 415%, P=0.011); Moreover, this was accompanied with a significant decrease in Ki-67 index (proliferation, day 7: average reduction: 81%, P=0.0003; day 21: average reduction: 60%, P=0.016 Prolonged retention of MSCs at the adventitia was evidenced by serial PET images of 89Zr-labeled cells. Conclusion These results indicate that adventitial transplantation of MSC decreases Mcp-1 gene expression accompanied with a reduction in VNH.

In 1965 Ferreira (1) described the isolation and properties of bradykininpotentiating factor (BPF), a crude peptidic extract from the venom of the South American snake Bothrops jararaca. Three years later Bakhle ( 2 ) demonstrated that BPF also prevented the conversion of angiotensin I to angiotensin I1 in vitro and similar effects were seen in the perfused lung (3) and in intact animals (4).These dual activities of BPF were also exhibited by the first peptide isolated and identified from BPF, Pyr-Lys-Trp-Ala-Pro, originally called BPPS5, and herein referred to as SQ 20,475 ( 5 ) . At least 8 other peptides from the venom of B. jararaca have been isolated by Ferreira, Bartelt, and Greene (6) and by Ondetti et aZ. (7). The latter investigators also determined the amino acid sequence of 6 of these.We have investigated the dual activities in vivo of these 6 peptides and of SQ 20,475, all of which were synthesized by Ondetti et a2. (8). Struotures of the 7 test peptides are shown in Table I. Materials mad Methods. Male rats of the Sprague-Dawley strain, 250 to 450 g, were anesthetized with urethane, 1.5 g/kg, im, and then tracheotomized. The trachea and the arteries and veins mentioned below were cannulated with polyethylene tubing of appropriate size. Blood pressure was monitored from a femoral artery via a Statham P23GH pressure transducer coupled to a Beckman dynograph. The rats were given atropine sulfate (1 mg/kg, iv) and heparin (250 units,/ 1Preliminary reports of parts of this work have been presented a t the NXV Int. kg, iv). Each test peptide, except the less soluble SQ 20,475, was dissolved in physiological saline and injected stat iv? 0.1 ml/dose, followed by 0.4 ml saline "wash-in" within the next 30 sec. SQ 20,475 was first dissolved in 0.1 il' NaOH, adjusted with 0.1 N HCl to about pH 8.5 and injected stat iv, 0.1 ml/dose, "washed-in" with 0.4 ml saline. Other injections of some of the test peptides were made im or sc, 0.1 ml/injection. Rats employed in experiments involving angiotensions I and I1 received a continuous infusion of pentolinium bitartrate (0.2 mg/kg/min) into a femoral vein. In experiments involving bradykinin, pentolinium was not infused.[ Ile5] -angiotensin I was purchased from Schwartz/Mann, [ Am1, Val5] -angiotensin I1 was kindly supplied by Dr. A. J. Plummer of Ciba Pharmaceutical Company, and bradykinin was purchased from Cyclo Chemical and Nutritional Biochemicals. These challenge peptides were administered stat iv, 0.1 ml/dose, in physiological saline, followed by 0.4 ml saline wash-in, in all experiments.Blood pressure responses to control doses of the challenging agent(s), i.e., to 0.10 or 0.31 pg/kg of angiotensin I and to 0.031 or 0.10 pg/kg of angiotensin I1 or to 1, 3, or 10 pg/kg of bradykinin, were first determined for each rat. The test peptide was then administered and the challenging agent (s) were injected repeatedly at 2-to 10-min initervals. Not until responses to the challenges were approximately equal to those seen in the control period was another injection of th...

Earlier reports (1-3)l described the ability of the nonapeptide SQ 20881 ( 150 mm Hg. 1 The initial demonstration of use d this class of peptides in ameliomtimg renal hypertension in three different models was first dexnibled by E. M. Krieger et al. [Lancet i, 2169 (1971)l for thle pentapeptide BPP,,.(b) Goldblatt-type hypertension. The left renal arteries of etherized rats of the Carworth Farms Nelson strain (CFN) were partially constricted with clips (id. 0.22 mm) fashioned from silver ribbon fn a modilfication of the technique of Goldblatt (10). The right renal arteries were left unclipped. In some of these animals, the right kidneys were removed ("l-kidney" Goldblatt model) during the same operation. These rats were used in experiments with SQ 20881 6-21 days after operation, again after plethysmographic evidence of hypertension.(c) Hypertension induced by aortic ligation. Ligation of the aorta with surgical silk between the origins of the renal arteries (1 1) was performed in etherized rats of the HSD strain. The animals were used in experiments with SQ 20881 6-8 days after operation when they had become hypertensive, as indicated by plethysmographic readings.(d) Hypertension induced by unclamping an acutely clamped renal pedicle. Plastictipped hemostatic forceps were applied to both renal pedicles of HSD rats after they had been anesthetized (see below). Six hours ,thereafter, the left renal pedicle was unclamped and iv infusion of test compound was begun as soon as the resultant hypertension had stabilized (about 10 min after unclamping ) ( 12).Anesthesia was induced by the administration of sodium pentobarbital, 40 mg/kg, ip, in Grollm...

Purpose. Type 2 diabetes is the leading cause of end stage renal disease in the United States. Atherosclerotic renal artery stenosis is commonly observed in diabetic patients and impacts the rate of renal and cardiovascular disease progression. We hypothesized that renal artery stenosis contributes to bilateral renal disease in diabetics. In our original study, we found that leptin-deficient diabetic (db/db) mice subjected to RAS developed severe and bilateral renal disease, with the contralateral (uncuffed) kidney showing features reminiscent of progressive diabetic nephropathy. In non-diabetic mice (WT), the cuffed kidney developed progressive atrophy, but the contralateral kidney showed minimal histopathologic alterations. In doing these studies, we observed increased sudden death in db/db mice with RAS, but not in WT mice with RAS. The objective of this study was to characterize the aortic and cardiac phenotype of db/db mice subjected to RAS. Methods. We developed a murine model of renal artery stenosis by placement of a polytetrafluoroethylene cuff on the right renal artery in db/db mice. We studied 109 WT and 95 db/db mice subjected to Renal artery stenosis (RAS) or sham surgery. Results. The mortality rate of db/db RAS mice was about 23.5%, whereas only 1.5% deaths were observed in WT RAS mice. Interestingly, 60% of mortality in the db/db mice occurred in the first two weeks following RAS surgery. Necropsy showed massive intrathoracic hemorrhage associated with aortic dissection. Aortas from db/db RAS mice showed more smooth muscle dropout, medial disruption, and hemorrhage than aortas from WT mice with RAS. Cardiac tissue from db/db RAS mice had more fibrosis than did cardiac tissue from WT RAS mice. Conclusions. Db/db mice subjected to RAS are prone to develop fatal aortic dissection, which is not observed in WT mice with RAS. The db/db RAS model provides the basis for future studies directed towards defining basic mechanisms underlying the interaction of hypertension and diabetes on the development of aortic lesions.