Arterial supply to the rat colon

Rats are often used as animal models in studies such as on intestinal transplantation and anastomosis healing, which require colectomy. Although detailed information regarding arterial supply is important to establish accurate and reproducible experimental procedures, this has not been studied in the rat colon. Therefore, we analysed the detailed arterial distribution pattern and its individual variations in the colon of 34 rats. The rat colon received colic branches of the ileocolic artery, and the right, middle and left colic arteries. The single left colic artery constantly arose from the caudal mesenteric artery and was distributed to the descending colon, whereas the others showed variations in number and distribution. The ileocolic artery gave rise to one (12%) or two (88%) colic branches supplying the proximal ascending colon, and these branches formed rich, mesh-like anastomoses along the initial portion of the ascending colon. One (74%) or two (26%) right colic arteries originated from the cranial mesenteric artery and supplied the ascending colon and right colic flexure. Moreover, one (38%), two (56%) or three (6%) middle colic arteries emerged from the cranial mesenteric artery and were distributed to the transverse colon, left colic flexure and proximal descending colon. In total, we categorized the individual variations in arterial branching and anastomosis into 11 patterns. Arterial supply to the rat colon showed a specific pattern and frequent individual variations. These findings thus provide essential information for establishing reproducible models of rat colic surgery.     

Role of phosphoinositide pathway in the formation of cardiac hypertrophy induced by pressure overload in rats

AIM: To investigate the role of phosphoinositide pathway in the formation of pressure-overload cardiac hypertrophy. METHODS: Cardiac hypertrophy was induced in male Sprague-Dawley rats with coarctation of abdominal aorta, whole heart weight/body weight ratio was tested after 10 or 30 days of operation. Content of Gαq/11 protein in left ventricle was detected by immunoblot analysis and concentration of IP₃ was measured by radioimmunoassay. RESULTS: At 10 and 30 days, whole heart weight/body weight ratio of coarctation aorta (CA) group was higher than that of sham-operated (SO) rats (P＜0.01). Protein Gαq/11 contents were not modified after 10 or 30 days of stenosis (P＞0.05). At 10 days, the level of IP₃ significantly increased in left ventricle of CA rats compared with the control animals (P＜0.05), but there was no difference in IP₃ level between CA and SO group after 30 days of operation. CONCLUSION: Phosphoinositide signaling pathway may play a role in the early stage of cardiac hypererophy induced by pressure overload.     

Usefulness of CT imaging for segmental lung lobe torsion without typical radiographic imaging in a Pomeranian

A 3-year-old, intact female Pomeranian presented with a 1-month history of coughing. Thoracic radiography showed focal infiltration of the left cranial lung lobe and widening of the cranial mediastinum. Subsequent computed tomography revealed torsion of the caudal segment of the left cranial lung lobe, which was confirmed by exploratory thoracotomy. There was no apparent underlying etiology for the condition. To the authors’ knowledge, this is the first report of lung lobe torsion in this breed and the first detailed CT imaging report for segmental lung lobe torsion.     

LEFT ATRIAL TO AORTIC ROOT INDICES USING TWO-DIMENSIONAL AND M-MODE ECHOCARDIOGRAPHY IN CAVALIER KING CHARLES SPANIELS WITH AND WITHOUT LEFT ATRIAL ENLARGEMENT

Two-dimensional (2-D) echocardiographic measurement of the left atrium (LA) has the potential to be more accurate than the standard M-mode method, because the LA body can be measured. We evaluated a 2-D method for measuring LA and aorta (AO) in a right parasternal short-axis view and compared it to the M-mode method. An index for LA size (LA/AO) was calculated in 166 cavalier King Charles spaniels, 56 normal and 110 dogs with mitral regurgitation (MR) of varying degrees secondary to chronic valvular disease. In normal dogs, the AO-2-D and LA/AO-2-D did not correlate to body weight (BW) or BW2; whereas, all M-mode values and the LA-2-D were significantly (p < .05) related to both BW parameters. In normal dogs, there was no difference between M-mode and 2-D indices. For all dogs (normal and dogs with MR) there was an 11% bias between the M-mode and 2-D index with the LA/AO-2-D being higher than the LA/AO-M. The association between the mean and the difference of the indices demonstrated a quadratic relationship. Dogs with a mean LA/AO of 2.0-2.5 showed the largest difference between the two indices. Small values for the 2-D coefficients of variation for respiration and stage of diastole were found; 3.4 and 3.1%, respectively. The 2-D index is more sensitive to LA enlargement than the M-mode index.     

运动性和高血压性心脏肥大心肌间质胶原网络重塑及其对左心室功能的影响

目的：探讨运动性和高血压性心脏肥大大鼠心肌间质胶原网络的重塑及其对左心室功能的影响。方法：采用跑台训练方式和腹主动脉缩窄术分别建立运动性心肌肥大大鼠模型和高血压性心肌肥大大鼠模型。心脏离体灌注测定左心室功能;扫描电镜和透射电镜观察心肌胶原网络重构;通过羟脯氨酸测定心肌胶原的浓度;Western-blot进行Ⅰ型、Ⅲ型胶原分析。结果：高血压大鼠的平均动脉压始终较高（P<0.05）,而训练组大鼠的动脉血压始终较低（P<0.05）;高血压大鼠的心脏舒张速率低于训练组（P<0.05）;高血压性大鼠左心室羟脯氨酸的浓度明显升高（P<0.05）,而训练大鼠左心室羟脯氨酸浓度并没有显著升高;高血压大鼠的左心室Ⅲ型胶原与Ⅰ型胶原的比值下降明显（P<0.05）,而训练组大鼠并没有表现出相同的结果。结论：运动训练可以使大鼠心肌细胞与间质胶原同步增长,心脏功能提高,心肌舒缩性能增强;而慢性高血压性大鼠导致心肌细胞与间质胶原不成比例的增长,间质胶原过度增生,心脏功能受到损伤。心肌间质胶原网络的重塑对大鼠左心室功能具有重要影响。     

真胃变位的发生与诊治

随着奶牛饲养小区的兴起，真胃变位的发生率有所增加，本文主要就真胃变位的发病原因、诊断方法、治疗措施进行简单介绍，以期对本病的预防和早期诊断能有所帮助。     

Reversed patent ductus arteriosus and multiple congenital malformations in an 8‐day‐old Arabo‐Friesian foal

An 8‐day‐old Arabo‐Friesian filly was presented with signs of severe dyspnoea, tachypnoea, coughing and cyanotic mucous membranes. On auscultation, a bilateral grade V/VI continuous heart murmur and heart rate of 155 beats/min (sinus tachycardia) were detected. Lung ultrasonography revealed pronounced comet tail artefacts indicating lung oedema. Echocardiography showed right ventricular hypertrophy, a 1.2 cm muscular ventricular septal defect with a left‐to‐right shunt, a stenotic bicuspid pulmonary valve and severe mitral and tricuspid valve regurgitation. Tricuspid regurgitation peak velocity indicated a right ventricular systolic pressure of 119 mmHg. The pulmonary artery was severely dilated and a 1 cm diameter patent ductus arteriosus was found. Colour flow Doppler showed systolic ductal flow reversal with right‐to‐left shunting through the ductus. Arterial partial oxygen pressure and saturation were lower in the metatarsal artery (25 mmHg, saturation 52.6%) than in the carotid artery (31 mmHg, saturation 64.3%). Due to the poor prognosis, the foal was subjected to euthanasia and necropsy confirmed the ultrasonographic findings. Patent ductus arteriosus is a rare condition and occurs most frequently in combination with tetralogy and pentalogy of Fallot. A genetic basis for congenital cardiac disease, especially for ventricular septal defects, in Arabians and for aortic rupture and aorto‐pulmonary fistulation in Friesians has been reported. Whether cross‐breeding leads to an increased prevalence is unknown. This is the first case report with echocardiographic visualisation of reversed ductal flow in a neonatal Arabo‐Friesian foal.