Distal Abdominal Aorta Research Articles

Staged Hybrid Repair for Extent II Thoracoabdominal Aortic Aneurysms and Dissections

Thoracoabdominal aortic aneurysms (TAAAs) often require intervention to prevent catastrophic aortic rupture. Open TAAA repair techniques have been well described with excellent long-term results. Outcomes, however, vary according to the extent of aortic pathology. In particular, Crawford extent II TAAAs are associated with higher rates of paraplegia, renal failure, pulmonary complications, and death. In a contemporary series, despite the use of adjuncts, such as, cerebrospinal drainage, cardiopulmonary bypass, and mesenteric perfusion, mortality and paraplegia after extent II TAAA repair range from 10%42% and 7%-32%, respectively. Thoracic endovascular aneurysm repair (TEVAR) has reduced the operative risk of repair compared with open surgical approach for isolated thoracic aortic aneurysms. At present, TEVAR alone cannot be utilized for extent II TAAA owing to involvement of the abdominal visceral vessels. Hybrid approaches to extensive TAAA have the potential to reduce operative risk. In this articles, we describe a 2-stage hybrid repair technique for extent II TAAAs or dissections. In the first stage, TEVAR is performed to address the proximal descending thoracic aorta—effectively converting an extent II TAAA to an extent III or IV TAAA. In the second stage, an open thoracoabdominal aneurysm repair is performed to address the distal thoracic and abdominal aorta. The staged approach distributes spinal cord ischemia from repair over time, potentially allowing vascular remodeling and collateral formation. This potentially may decrease paralysis rates. The hybrid approach also obviates the need for a high proximal thoracic aortic anastomosis. This reduces the extent of the incision, eliminates dissection around the arch and recurrent laryngeal nerve, and allows a simpler thoracic aortic anastomosis. This may potentially reduce operative time and recurrent laryngeal nerve injury and prevent respiratory failure.

Herald Bleeding: A Hidden Catastrophe

Purpose: The word “herald” means to indicate or sign that something is about to happen. Herald bleeding is defined as an episode of hemorrhage, often accompanied by abdominal pain, which may precede, by hours to weeks, a catastrophic hemorrhage. Case Report: A 57-year old male with past medical history of abdominal aortic aneurysm repair around 15 years ago and peptic ulcer disease diagnosed 10 years ago, presented to the hospital with maroon-colored stool of 2 weeks' duration, along with a few days' onset of melena, coffee ground emesis, and sharp epigastric pain. Medications included Plavix, Protonix, Tramadol, and occasional NSAIDs. Physical examination revealed normal vital signs, and epigastric tenderness without any peritoneal signs. Laboratory analysis showed hemoglobin of 7.1 mg/dL, platelets of 355,000 /μL, and INR of 1.2. A CT scan of abdomen and pelvis with IV contrast showed 1.6 x 1.6 x 1.8 cm saccular aneurysm originating from the termination of the distal abdominal aorta without adjacent acute findings, and 3.1 cm aneurysm infrarenal abdominal aorta with circumferential thrombus. Upper gastrointestinal endoscopy showed L.A. grade B esophagitis and hiatal hernia. Colonoscopy showed a scant amount of blood in colon without any obvious bleeding source. Tagged RBC scan was negative. Second look endoscopy was performed with pediatric colonoscope, revealing 3- 4 mm clean-based ulcer over the fourth portion of duodenum, and two vascular clips were placed. Vascular surgery was consulted and, based on the location of the ulcer on the lateral wall of the abdominal aorta, along with CT finding of induration and inflammation of the aortic graft right at the renal arteries, suspicion was made for aortoenteric fistula (AEF). The patient underwent emergent laparotomy and was found to have AEF. The patient then underwent repair of AEF with a successful outcome. Discussion: AEF is a direct connection between abdominal aorta and gut, most commonly duodenum. It occurs in 0.3-4% of patients who underwent open AAA repair. The most common clinical manifestations are upper or lower gastrointestinal bleeding (herald bleeding; 64%), abdominal pain (32%) and a pulsatile abdominal mass (25%). The proposed theories for the formation of primary ADF are direct wear and inflammatory destruction triggered by infection, foreign bodies or erosions. The characteristic site of formation is the third or fourth part of the duodenum. AEF should be considered in all patients with GI bleeding and a history of AAA or previous aortic revascularization with prosthetic graft. A high index of suspicion is the key. The mortality rate of untreated AEF is 100%. Surgical intervention is mandatory for survival and successful outcome.

Customized fenestrated endovascular graft repair of abdominal aortic aneurysm with concomitant horseshoe kidney

The occurrence of an abdominal aortic aneurysm (AAA) with horseshoe kidney (HSK) is an uncommon but complex surgical problem. This report outlines three such cases, the particular issues encountered and how customized endovascular grafts were successfully used to overcome them. Case one shows an accessory renal artery arising from the left common iliac artery, case two shows a right accessory renal artery from the AAA sac and case three has the right renal artery coming off the distal abdominal aorta within the sac. Across three patients, each graft had a single custom fenestration, which preserved a total of three major vessels with no change in renal function. Customized endografts are a viable tool to preserve aberrant vessels and thus renal mass in AAA and HSK. Customized endografts require an extensive work-up and are currently expensive to fabricate. However they are rapidly evolving as a mainstream tool in vascular surgery and provide a solution in cases of aberrant visceral vasculature.

Exercise Training for Peripheral Arterial Disease

Exercise Training for Peripheral Arterial Disease

Coarctation-induced degenerative abdominal aortic aneurysm in a porcine model

Hemodynamic stress participates in the initiation and progression of aneurysmal degeneration. Coarctation increases flow-mediated stress on the aortic wall. We tested the hypothesis that prolonged coarctation of an infrarenal abdominal aorta (AA) segment leads to abdominal aortic aneurysm (AAA) formation in mini pigs. An asymmetric, funnel-shaped flow path was created by constricting the infrarenal AA segment of Taiwanese Lanyu mini pigs (age, 7-10 months; male and female) wrapped with an 8-mm-wide expanded polytetrafluoroethylene Teflon strip for 4 weeks (4w), 8 weeks (8w), and 12 weeks (12w) (seven pigs per group). This mimics the tortuous aneurysm neck in human AAA, which increases downstream flow-mediated stress. Significant flow disturbance resulting from moderate coarctation was indicated by a pulsatility index reduced to one third the inherent levels. Sham control pigs received Teflon wrapping without coarctation. Aneurysm characterized by progressive medial degeneration occurred at the terminal AA after 12w coarctation. The outer dimension enlargement of the distal AA exceeded 50% compared with that of the proximal AA at 4w, 8w, and 12w postcoarctation (sham, 1.0; 4w, 1.7 ± 0.08; 8w, 1.5 ± 0.09; 12w, 1.7 ± 0.01). Lumen ratio of the distal-to-suprarenal AA increased time dependently, with 12w postcoarctation exhibiting significant increase (sham, 1.0 ± 0.05; 4w, 1.1 ± 0.11; 8w, 1.4 ± 0.20; 12w, 1.5 ± 0.09). In the distal AA, elastic lamellae exhibited fragmentation at 4w and more pronounced fragmentation with decreased density at 8w and 12w postcoarctation. Medial collagen density exhibited the trend to increase at 4w and 8w but was reversed at 12w postcoarctation. Smooth muscle exhibited disarray and nuclear density decrease at 8w and 12w postcoarctation (sham, 6966 ± 888/mm; 4w, 5747 ± 1340/mm; 8w, 4153 ± 323/mm; 12w, 4083 ± 465/mm). Gelatin zymography revealed that matrix metalloproteinase-9 activity markedly increased at 4w postcoarctation. Prolonged moderate coarctation caused regional hemodynamic stress and thereby induced degenerative AAA in the terminal AA.

Mid-aortic dysplastic syndrome as a rare cause of hypertension in young

Introduction: Mid-aortic syndrome (MAS), coarctation of abdominal aorta is a rare disease with only 200 reported cases. It is characterized by constriction of distal thoracic and/or abdominal aorta and its branches, therefore is also known as abdominal aortic coarctation. The MAS is characterized radiologically by severe narrowing of abdominal aorta and its branches and most of these patients usually die due to progressive severe hypertension before the age of 35-40 if left untreated. Case Report: A 13-year-old boy was admitted with persistent headache and vomiting for one month and repeated generalized tonic clonic seizures for two days. His past history was unremarkable. The highlight of the clinical examination blood pressure was 240/150 mmHg in both the upper limbs, and all peripheral pulses were palpable. Blood pressure was similar in upper and lower limbs and a systolic bruit heard over the epigastrium. Ultrasonography showed a localized narrowing of a suprarenal segment of the abdominal aorta with an abrupt focal dilatation of the abdominal aorta approx 1.7cm below origin of superior mesenteric artery. Magnetic resonance angiography of the aorta and its branches showed a distinct fusiform dilatation of abdominal aorta just below the origin of the superior mesenteric artery. Focal narrowing of abdominal aorta was noted just proximal to the dilatation. Conclusion: We diagnosed a case of mid-aortic coarctation with post stenotic dilatation associated with left renal artery stenosis leading to secondary hypertension in a teenage boy presenting with reversible posterior leukoencephalopathy and seizures. The boy was referred for vascular surgery but the patient refused any operative procedure.

Retrograde iliac artery dissection

A 42-year-old man presented with acute abdominal pain. He was normotensive and had no history of smoking, diabetes, surgeries, or trauma, but had hypertension controlled with one drug. There was no family history of vascular disease. The physical examination revealed hypersensibility in the lower abdomen, without any palpable mass. Femoral and distal pulses were normal. Ultrasound imaging revealed ectasia of the right common iliac artery (RCIA) and wall hematoma but no free fluid in the abdominal cavity. Computed tomography angiography (CTA) showed a slightly dilated RCIA and dissection from the RCIA to the distal abdominal aorta (retrograde dissection; A/Cover). The patient was placed under general anesthesia, and a transperitoneal approach was initiated. An extensive hematoma and inflammatory reaction were seen next to the anterior wall of the aorta and the RCIA. The site of the RCIA dissection was the iliac bifurcation extending to the distal abdominal aorta. The arterial wall was extremely thin and fragile and was reconstructed using a bifurcated polytetrafluoroethylene graft (B). Histology revealed myxoid degeneration and fragmentation of the elastic fibers of the RCIA. Control CTA imaging on postoperative day 6 did not reveal any problems (C), and the patient was discharged on postoperative day 7 without complications. At 50 days postoperatively, the patient was doing well.

Wall tracking for the assessment of aortic distensibility during a follow up of 49 days in Angiotensin II-infused ApoE-/- mice

Introduction. Ultrasound wall tracking allows assessing the distension of superficial arteries. While the technique is well established in humans, wall tracking is challenging in mice due to the smaller size of the arteries. The aim of this study was to assess the feasibility of sequential distension measurements on the aorta of an aortic aneurysm mouse model. Methods. In-house bred male ApoE -/- mice were implanted an osmotic pump filled with Angiotensin II. Ultrasound data were obtained with a high-frequency ultrasound apparatus equipped with a linear array probe. All measurements were performed by a single operator. M-mode images of proximal and distal abdominal aorta were obtained in 5 animals on day 1, 6, 14, 30 and 49. Dedicated software was employed for wall tracking using stored demodulated Radio Frequency (RF) data. Resulting curves were processed to calculate the diastolic diameter and the relative (DeltaD/D) arterial diameter distension. Results. Proximal abdominal aorta diastolic diameter presented higher values than distal abdominal aorta, as expected. However, diameter values in both locations decreased through time, reaching a minimum at day 30. DeltaD/D progressively decreased from baseline until day 14 in both locations, after which values increased to near baseline levels at day 49. Conclusion. RF-based Vessel wall tracking of the abdominal aorta in an aneurysmatic mouse model is feasible. Our data suggest an initial narrowing and stiffening of the abdominal aorta up to day 14, followed by an increase in diameter and distensibility, a phenomenon that is possibly due to Angiotensin II-induced smooth muscle contraction.

Use of a novel abdominal aortic tourniquet to reduce or eliminate flow in the common femoral artery in human subjects

Penetrating injuries of proximal femoral and iliac vessels are a common cause of death on the battlefield. Previous studies have shown that by applying 80 lb to 140 lb of pressure externally over the distal abdominal aorta, flow can be ceased in the common femoral artery (CFA). It has also been demonstrated that in a porcine model, an externally applied pneumatic abdominal aortic tourniquet (AAT) can occlude the aorta and inferior vena cava for 60 minutes without bowel injury or significant potassium elevations.The objectives of this study were (1) determine if AAT use in humans results in flow cessation in the CFA, (2) measure the pressure required to cease flow in the CFA, and (3) measure discomfort associated with application of the AAT. Pulse wave Doppler measurements were taken in supine volunteers at the right CFA. The AAT was placed just above the iliac crests over the anterior abdomen. The AAT was inflated using a hand pump with an integrated manometer. Measurements were taken every 30 mm Hg. Discomfort was measured using a 10-point pain scale. In all subjects, flow was reduced in the CFA. Flow ceased in seven of nine subjects at a median pressure of 180 mm Hg (150-230 mm Hg). Median discomfort at ceasing of flow was 7 (3-10), returning to 0 after device removal. The AAT device was effective at reducing flow in the CFA and ceased flow in most of the subjects. Application of the device was associated with discomfort varying from moderate to severe and resolving with device removal.

Large arteriovenous fistula between the common iliac artery and the vein after blunt trauma

A 62-year-old man presented to the emergency department with dyspnea on exertion and bilateral leg edema 4 days after falling down stairs and sustaining injuries. The physical examination showed mild respiratory distress and blood pressure of 130/80 mm Hg. Lung examination revealed bilateral basilar rales. A chest radiograph showed mild pulmonary congestion and pleural effusion but no cardiomegaly (A). An axial computed tomography scan (B) showed fracture and spondylosis of the lower lumbar spine and sacrum (*) and a 50-mm thrombosed pseudoaneurysm of the right common iliac artery (CIA) that communicated with the right common iliac vein (CIV) near the distal inferior vena cava (C and D). Transthoracic echocardiography revealed normal mitral, aortic and tricuspid valves, mild dilatation of all cardiac chambers, and normal contraction of the ventricles. There was moderate pulmonary hypertension (right ventricular systolic pressure, 60 mm Hg). The patient’s arteriovenous fistula (AVF) was surgically repaired through a median laparotomy. After proximal and distal control of the aorta and the inferior vena cava was obtained, the pseudoaneurysm was excised, and the AVF defect was repaired with interrupted polypropylene sutures. The size of the AVF was 40 10 mm. After a proximal anastomosis at the distal abdominal aorta and obliteration of both common iliac arteries, distal anastomoses were constructed to the external iliac arteries with a Dacron graft. The patient had an uneventful recovery and was discharged 10 days after surgery. Postoperative computed tomography showed successful excision of the pseudoaneurysm and repair of the AVF.

Long-segment thoracoabdominal aortic occlusions in childhood

Developmental coarctation, hypoplasia, and occlusion of the abdominal aorta is a rare disease encompassing many differing etiologies and diverse methods of treatment. Long-segment thoracoabdominal aortic occlusion, an extreme manifestation of this disorder, has not previously been reported in children. Two pediatric patients with this entity, a 5- and 13-year-old with uncontrolled hypertension, underwent extensive arterial reconstructions for this entity and provided the impetus for this report. An ascending thoracic aorta to infrarenal aortic expanded polytetrafluoroethylene bypass was undertaken in the younger child. A distal thoracic aorto-bi-iliac artery expanded polytetrafluoroethylene bypass, with implantation of the left renal artery to one graft limb and a right renal artery bypass originating from the other limb, was performed in the older child. There were no major perioperative complications. Both patients were discharged with easily controlled blood pressures. They have remained normotensive at 13 and 14 months follow-up.

Thoracoabdominal aortic aneurysm repair using hypothermic cardiopulmonary bypass and circulatory arrest.

Thoracoabdominal aortic aneurysm repair using hypothermic cardiopulmonary bypass and circulatory arrest.

Surgical Repair of Middle Aortic Syndrome in a Three-Year-Old Patient

Middle aortic syndrome is a rare variation of aortic coarctation that is localized to the distal thoracic and abdominal aorta, and can involve the visceral and renal arteries. Irreversible organ damage and end-stage congestive heart failure may be the possible harmful complications of this disease in untreated patients. We report a three-year-old patient with diffuse thoracic and abdominal aorta hypoplasia treated with a thoracic to abdominal aortic bypass graft.

Application of Duplex Ultrasonography in the Midaortic Syndrome

Objective Midaortic syndrome is a rare condition found primarily in children that causes stenosis of the abdominal aorta and its proximal branches. Duplex interpretation criteria derived from adults do not necessarily apply to the pediatric population but are sometimes used empirically in specific cases. We report the case of a 5-year-old girl whose aorta and renal arteries were studied by duplex ultrasound, with anatomic and radiologic correlation. Case Report The patient was a 5-year-old girl with refractory hypertension on multiple antihypertensive medications. Her initial diagnosis of midaortic syndrome was made via duplex ultrasound. The findings were confirmed by angiography and showed smooth narrowing of the mid- to distal abdominal aorta with concomitant bilateral renal artery origin stenosis. Surgical repair of the aorta was performed with the use of a patch angioplasty technique with pulmonary artery homograft. The left renal artery was re-implanted onto the infrarenal aorta and an aorta to right renal artery bypass graft was placed using autogenous left internal iliac artery. Duplex ultrasound was then used to evaluate the success of the surgical repair. Conclusion Duplex ultrasound proved effective in the preoperative and postoperative care of this small child with midaortic syndrome and renal artery stenosis. The standard adult criteria for renal artery stenosis can be used selectively in children to assist in the diagnosis of unusual vascular conditions.

Antiphospholipid Syndrome and the Aorta: A Rare Presentation

To the Editor: Antiphospholipid syndrome (APS) is a disorder of coagulation that is usually manifested by arterial or venous thrombosis, or pregnancy-related complications such as miscarriage, stillbirth, preterm delivery, or severe preeclampsia1. The syndrome occurs due to the autoimmune production of antibodies against the cell membrane phospholipid. A 39-year-old woman presented to the emergency department with severe abdominal pain. An abdominal computed tomography (CT) angiogram showed complete occlusion of the distal abdominal aorta from the origin of the left renal artery, common and external iliac artery occlusion, extensive infarcts of kidneys and spleen, and a superior mesenteric artery thrombus (Figures 1 and 2). Figure 1. Abdominal computed tomography coronal slice shows large aortic thrombus extending infrarenally. Figure 2. Axial computed tomography reveals large aortic thrombus and left renal infarcts. She had a history of intermittent left upper-quadrant abdominal pain with radiation to the back with nausea and diapheresis. Her history was significant for hypertension, a remote history of peptic … Address correspondence to Dr. Shroff; E-mail: anjali.shroff{at}gmail.com

MEMS Thermal Sensors to Detect Changes in Heat Transfer in the Pre-Atherosclerotic Regions of Fat-Fed New Zealand White Rabbits

Real-time detection of pre-atherosclerotic regions remains an unmet clinical challenge. We previously demonstrated the application of micro-electro-mechanical systems (MEMS) to detect changes in convective heat transfer in terms of sensor output voltages in the zone of flow reversal in an in vitro stenotic model. We hereby demonstrated changes in sensor output voltages in the pre-atherosclerotic regions in the New Zealand White rabbits fed on hypercholesterolemic diet (HD). After 8 weeks, we observed that mean output voltages (V(ave)) were similar in the distal aortic arch, thoracic, and abdominal aortas in the normal standard diet (ND) group, consistent with an absence of atherosclerosis. In HD group, V(ave) increased in the distal aortic arch (HD: V(ave) = 1.05 ± 0.04 V; ND: V(ave) = 0.12 ± 0.01 V, n = 3, p < 0.05) and in the thoracic aortas (HD: V(ave) = 0.72 ± 0.06 V; ND: V(ave) = 0.13 ± 0.024 V, n = 3, p < 0.05), consistent with the histological presence of pre-atherosclerosis. Despite HD diet, V (ave) magnitudes were similar to ND group in the abdominal aortas (HD: V(ave) = 0.14 ± 0.003 V; ND: V(ave) = 0.14 ± 0.004 V, n = 3), corroborating histological absence of pre-atherosclerosis. Hence, MEMS thermal sensors provide a new approach to detect changes in convective heat transfer in the pre-atherosclerotic regions.

Attenuated atherogenesis in apolipoprotein E-deficient mice lacking amyloid precursor protein

ObjectiveRecent evidence suggests that amyloid precursor protein (APP) is overexpressed in atherosclerosis-prone regions of mouse aorta. We therefore investigated in the present study whether APP has a role in the progression and composition of atherosclerotic plaques. Methods and resultsApolipoprotein E-deficient (apoE−/−) mice were crossbred with animals lacking APP (APP−/−). After 16 weeks on a Western-type diet, apoE−/− and APP−/−/apoE−/− mice showed similar cholesterol levels. However, atherosclerotic plaque size was significantly reduced in the distal thoracic aorta (90% reduction) and abdominal aorta (75% reduction) of APP−/−/apoE−/− mice as compared to apoE−/−. Plaques at the level of the aortic valves were not different in size, but showed a more stable phenotype in APP−/−/apoE−/− mice, as indicated by a reduced macrophage content, an increased amount of collagen and a thicker fibrous cap. ConclusionOur findings provide evidence that lack of APP attenuates atherogenesis and leads to plaque stability.

To what extent does aortic pulse wave velocity estimate early atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic rabbits?

Pulse wave velocity (PWV), an index of arterial stiffness, is dependent not only on structural alterations in arterial wall but also on distending pressure, which could be related to wall distensibility. We investigated the efficacy of aortic PWV (AoPWV) for detecting early to moderate atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbits. Pressure waves were recorded at the ascending, and proximal and distal abdominal aortas in 13 male normal and KHC rabbits aged 12 months under pentobarbital anesthesia when angiotensin II or sodium nitroprusside was infused intravenously. AoPWV was compared between the two rabbit groups at different mean arterial pressure (MAP) levels. Vascular diameter (D(m)) was measured using an intravascular ultrasound imaging system in the proximal thoracic and proximal abdominal aortas to determine pressure-strain elastic modulus (E(p)). AoPWV was correlated to MAP in the two rabbit groups (P < 0.001). AoPWV was slightly but significantly greater (< 0.5 m s(-1)) in the KHC rabbit group than in the normal rabbit group at MAP level >80 mm Hg (P < 0.01). The value of h/D(m) (h, wall thickness) was significantly high in the KHC rabbit group at any MAP level (P < 0.001) in these aortic regions. There was no significant difference in E(p) and D(m) between the two rabbit groups at any MAP level. AoPWV showed only a slight but significant increase in the young KHC rabbits at different MAP levels, which was mainly due to the increased h/D(m). AoPWV could underestimate aortic stiffness due to early to moderate atherosclerosis if AoPWV was adjusted for arterial pressure level.

Abdominal Aortic Chondrosarcoma in a Dog

A 14-year-old, mixed breed dog was presented with acute pain and paresis of the hindlimbs. Ultrasonography revealed an intraluminal mass and an abrupt halt of blood flow signal in the distal abdominal aorta. The mass had homogeneous hyperechoic echotexture compared with blood flow. Although clinical presentation suggested a thromboembolism and pituitary dependent hyperadrenocorticism was suspected as a predisposing cause based on adrenal function tests and ultrasonography, an aortic chondrosarcoma originating from the distal abdominal aorta was diagnosed with histologic examination. Primary aortic sarcoma is extremely rare, and extraskeletal chondrosarcoma is only reported in 2 cases previously. Aortic neoplasm should be included in differential diagnosis when an intraluminal aortic mass is observed on ultrasonography and acute paresis of hindlimbs is shown.

The diabetes-induced functional and distributional changes of the alpha 1-adrenoceptor of the abdominal aorta and distal mesenteric artery from streptozotocin-induced diabetic rats

BackgroundThe aim of this study was to evaluate the effect of diabetes on the function and distribution of vascular α1-adrenoceptors in the abdominal aorta and distal mesenteric artery from streptozotocin (STZ)-induced diabetic rats at the level of the α1-adrenoceptor subtypes.MethodsDiabetes was induced by a single intravenous injection of STZ (60 mg/kg) in 8 week-old male Sprague-Dawley rats (n = 11). Age-matched normal rats (n = 14) were used as a control group. Four weeks after STZ injection, the tilting-induced change of the mean arterial pressure was recorded. The α1-adrenoceptor subtypes mediating the contractions of the distal mesenteric artery and abdominal aorta were investigated using the agonist phenylephrine and subtype-selective antagonists that included prazocin, 5-methylurapidil and BMY 7378. The expressions of the α1-adrenoceptor subtypes of each artery were examined by immunofluorescence staining using the subtype selective antibodies.ResultsThe recovery of the mean arterial pressure was delayed after positional change in the diabetic rats. Compared with that of the normal rats, the contractile response to phenylephrine was increased in the abdominal aortas and it was decreased in the distal mesenteric arteries in the diabetic rats. In addition, compared with the normal rats, the fluorescent intensity of all the α1-adrenoceptor subtypes was increased in the abdominal aortas and it was decreased in the mesenteric arteries of the diabetic rats.ConclusionsDiabetes increased the contractility of the abdominal aorta in response to phenylephrine, yet diabetes decreased that of the mesenteric arteries in the STZ-induced diabetic rats. Those results are mainly based on the overall change of the α1-adrenoceptor, and not on the change of the specific α1-adrenoceptor subtypes.