MORPHOLOGY OF THE RESPIRATORY PARTS OF THE LUNGS IN METABOLIC SYNDROME: MORPHOMETRIC AND MORPHOLOGICAL CHANGES IN ALVEOLI OF RATS

Metabolic syndrome (MS), recognized as a complex interplay of metabolic disturbances including but not limited to insulin resistance, central obesity, dyslipidemia, and systemic hypertension, poses a significant threat to overall physiological homeostasis, with particularly deleterious effects on the respiratory system. This comprehensive and in-depth study meticulously examines the intricate morphological and morphometric modifications occurring within the alveolar complexes of the lungs in adult white laboratory rats subjected to a rigorously controlled experimental induction of MS. By employing a substantial cohort of 120 white Wistar rats, each weighing between 180-220 grams and spanning an age range from 30 to 120 days, the research design incorporated a balanced division into control and experimental groups to facilitate robust comparative analyses. Advanced histological techniques were utilized, encompassing standard hematoxylin-eosin (H&E) staining for general tissue architecture visualization, Masson's trichrome for precise collagen deposition assessment indicative of fibrotic processes, periodic acid-Schiff (PAS) for glycoprotein and mucopolysaccharide detection, and targeted immunohistochemical protocols focusing on surfactant protein C (SP-C) to evaluate type II alveolocyte functionality and CD31 to quantify endothelial integrity and vascular density. Complementing these qualitative approaches, quantitative morphometric evaluations were conducted using state-of-the-art digital imaging software, while statistical rigor was ensured through parametric and non-parametric tests to chronicle the temporal progression of changes. Principal findings in the experimental cohort reveal a progressive and statistically significant thickening of alveolar walls, escalating from a baseline mean of 2.3 ± 0.2 μm in controls to 3.0 ± 0.3 μm in affected subjects, alongside an expansion of alveolar barriers from 28.0 ± 2.1 μm to 32.5 ± 2.5 μm, and a concomitant reduction in alveolar surface area from 630 ± 34 μm² to 575 ± 40 μm². These quantitative shifts are paralleled by qualitative histological evidence of cellular dystrophy in alveolocytes, extensive interstitial fibrosis, endothelial cell swelling, basal membrane thickening, capillary lumen narrowing, and the presence of microthrombi, all of which collectively impair pulmonary gas exchange efficiency and reduce overall lung elasticity. The underlying mechanistic pathways are attributed to hyperglycemia-induced advanced glycation end-products (AGEs) formation leading to protein cross-linking and structural rigidity, elevated levels of free fatty acids promoting oxidative lipid peroxidation and subsequent cellular membrane damage, and an upregulation of pro-inflammatory mediators such as tumor necrosis factor-alpha (TNF-α) and interleukins that orchestrate fibrotic cascades via fibroblast activation and extracellular matrix deposition. The chronological dynamics of these alterations demonstrate an accelerating severity from the initial 30-day mark through to 120 days, emblematic of the chronic and insidious nature of MS-driven pulmonary pathogenesis. The novelty of this investigation lies in its holistic integration of MS-precipitated alveolar disruptions with the broader context of postnatal ontogenetic development, providing empirically grounded insights that extend beyond mere observation to offer a foundational framework for early diagnostic strategies, preventive interventions, and therapeutic innovations in human populations afflicted by MS. Furthermore, this work contributes substantially to the evolving discourse on MS-pulmonary interrelationships, advocating for multidisciplinary approaches that incorporate metabolic correction, anti-inflammatory therapies, and pulmonary rehabilitation to mitigate the respiratory comorbidities associated with this syndrome, ultimately aiming to reduce morbidity and mortality rates in at-risk demographics worldwide.

Hali tarjima qilinmagan