Influence of type 1 diabetes mellitus on angiotensin-II converting enzymes and neurodegenerative factors in the hypertensive rat
Hypertension and diabetes are recognized as risks for cerebrovascular disease. The present study examined
the expression and regulation of angiotensin-converting enzyme (ACE), ACE2, and chymase in the rat frontal
brain cortex to assess their roles in neurodegeneration. Frontal cortex brain tissues from control, streptozotocininduced
diabetic, spontaneously hypertensive rats (SHR), and SHR-diabetic (SHR-D) rats were analyzed using
immunoblot and biochemical techniques. The expressions of ACE, ACE2, chymase, neurotrophic factors (brainderived
neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB), glutamine synthetase), apoptotic
markers (caspase-3, cytochrome c), and oxidative stress markers were evaluated. ACE, ACE2, and chymase were
expressed in all groups. Diabetic and hypertensive rats, alongside elevated chymase levels, exhibited significant
ACE upregulation and ACE2 downregulation compared to controls. Neuroprotective factors BDNF, TrkB, and
glutamine synthetase were markedly reduced in diabetic and hypertensive-diabetic rats, whereas apoptotic
markers (caspase-3, cytochrome c) were significantly increased. Oxidative stress, measured by glutathione (GSH)
and thiobarbituric acid reactive substances (TBARS), was higher in diabetic and hypertensive groups than in the
controls. The combined effects of ACE upregulation, ACE2 downregulation, and increased chymase expression
in the hypertensive-diabetic brain cortex may amplify pathological processes. These changes likely enhance
oxidative damage and apoptotic pathways, which contribute to neurodegeneration. This study highlights how
oxidative stress and the renin-angiotensin system interact critically in cerebrovascular and neurodegenerative
disorders linked to diabetes and hypertension.
Hypertension and diabetes are recognized as risks for cerebrovascular disease. The present study examined
the expression and regulation of angiotensin-converting enzyme (ACE), ACE2, and chymase…
Diabetic retinopathy (DR) is a significant complication of diabetes that results in retinal damage and the risk of blindness.
Branched-chain amino acids (BCAAs) are essential amino acids that…
Branched-chain amino acids (BCAAs) are essential for various metabolic and physiological functions. The enzymes
responsible for breaking down and transporting them are organized in a tissue-…