Isah Murtala Bindawa, Masola Bubuya
Discipline of Biochemistry, School of Life Sciences, University of KwaZulu-Natal, Westville CampusPrivate Bag X54001, Durban 4000, South Africa.
Int J Physiol Pathophysiol Pharmacol. 2017 Nov 1;9(5):128-136. eCollection 2017.
The small intestine (SI) is the main site for food absorption and glutamine utilization hence critical in metabolic disorders that involve energy balance such as diabetes. This study investigates the effects of oleanolic acid (OA) on SI morphology and some enzymes of glutamine metabolism in male Sprague-Dawley diabetic rats. High dose STZ-induced diabetes (HDD) and low dose STZ-induced diabetes (LDD) were induced by intraperitoneal injection of 60 and 40 mg streptozotocin/kg body weight respectively. Non-diabetic and diabetic rats were treated for two weeks with OA, insulin or OA + insulin in HDD study while animals in the in LDD study were treated with OA. There was significant (P<0.05) increase in the weight of the SI of diabetic animals and of villus height (VH) in the jejunum and duodenum of HDD animals. OA and insulin treatment significantly decreased VH in duodenum of HDD animals while OA treatment profoundly increased VH in normal rats. Jejunal of phosphate-dependent glutaminase (PDG) activity was unaffected by diabetes however alanine aminotransferase, aspartate aminotransferase and glutamate dehydrogenase activities were significantly (P<0.05) elevated by diabetes and treatments decreased these elevated aminotransferase activities. It is suggested that the intestine meets the energy demand in diabetes by modulating the activities of aminotransferases without change in PDG activity.
小肠（SI）是食物吸收和谷氨酰胺利用的主要部位，因此在涉及能量平衡的代谢紊乱（如糖尿病）中至关重要。本研究调查了齐墩果酸（OA）对雄性Sprague-Dawley糖尿病大鼠小肠形态和谷氨酰胺代谢的一些酶的影响。高剂量链脲佐菌素诱导的糖尿病（HDD）和低剂量链脲佐菌素诱导的糖尿病（LDD）分别通过腹腔注射60和40 mg链脲佐菌素/千克体重诱导产生。在HDD研究中，非糖尿病和糖尿病大鼠用OA、胰岛素或OA +胰岛素治疗两周，而在LDD研究中的动物用OA治疗。糖尿病动物的小肠重量以及HDD动物空肠和十二指肠的绒毛高度（VH）有显著（P<0.05）增加。OA和胰岛素治疗显著降低了HDD动物十二指肠的VH，而OA治疗显著增加了正常大鼠的VH。空肠中磷酸依赖性谷氨酰胺酶（PDG）的活性不受糖尿病影响，然而糖尿病显著（P<0.05）提高了丙氨酸转氨酶、天冬氨酸转氨酶和谷氨酸脱氢酶的活性，并且治疗降低了这些升高的转氨酶活性。研究表明，在糖尿病中，肠道通过调节转氨酶的活性来满足能量需求，而PDG活性没有变化。
