STUDY OF CORRELATION BETWEEN SYSTOLIC BLOOD PRESSURE AND ANGIOTENSIN CONVERTING ENZYME (ACE) ACTIVITY IN STZ INDUCED DIABETIC RATS

Due to homeostatic and regulatory potentials of nitric oxide (NO) in vascular physiology, regulatory systems that determine NO bio-synthesis and bioavailability have been the subject of extensive research in molecular medicine. In the field of vascular system pathophysiology, endothelial nitric oxide synthase (eNOS) which is the major producer and regulator of NO in vascular tissues has received the most attention. Impairment of NO bioavailability (NO quenching) is a common feature in poorly controlled diabetics due to increased catabolism and decreased production of NO. Such impairment in severe forms could end to vasodilation breakdown in peripheral tissues (mainly in skeletal muscles) and defective regional blood flow, that in turn disturb insulin-dependent glucose uptake ensuing insulin resistance state. The phenotypic impact of an eNOS gene polymorphism at position 786*C/T (that its functionality has been revealed already) on genetic propensity to diabetic retinopathy is evaluated in a British-Caucasian population with type 1 diabetes (T1DM). In contrast to genotypes, there was a significant difference in distribution of allele frequencies between T1DM patients (n= 249) and healthy controls (n= 104) (p= 0/036), that may imply eNOS and/or NO involvement in development of T1DM. Most notably a significant difference also was evident in allele frequency between retinopaths (n= 134) and healthy controls (p= 0/02). No significant difference was detected when the genotype/allele frequencies were compared between retinopaths (n= 134) and non-retinopaths diabetics (n= 115) (p=NS). Our data is compatible with previous studies which demonstrated that allele C of eNOS 786*C/T polymorphism is associated with increased HbA1c levels. By emphasizing the phenotypic and prognostic value of the abovementioned polymorphism, our data calls for further investigations to find out whether this polymorphism can be employed as a genetic marker in clinical medicine to recognize high-risk diabetics at the time of diabetes onset/diagnosis.