MORPHOLOGICAL CHARACTERISTICS OF REPARATIVE OSTEOGENESIS UNDER CONDITIONS OF CHRONIC LEAD INTOXICATION DURING PHARMACOLOGICAL CORRECTION IN AN EXPERIMENT

<jats:p>&lt;p&gt;Aim — to assess the effect of combined metabolic correction (succinic acid, calcium citrate, vitamin D₃) on the morphological dynamics of reparative osteogenesis under ongoing lead intoxication.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;Materials and methods. Fifteen rats of experimental group II received water with lead acetate (50 mg/kg); after creation of a monocortical defect of the right femoral diaphysis (week 4, diameter 1.0 mm) the diet was supplemented with succinic acid (100 mg/kg), calcium citrate (200 mg/kg) and vitamin D₃ (500 IU/kg). Animals were withdrawn on days 7, 14, 21 and 28; sections were stained with haematoxylin–eosin and Masson trichrome (×100, ×400).&lt;/p&gt;&lt;p style="text-align: justify;"&gt;Results. Under correction, repair proceeded more actively than in untreated animals: as early as day 7 angiogenesis and osteoblastic activity recovered, inflammatory infiltration and haemorrhages were absent, and cartilage fragments appeared. By days 14–21 a well-consolidated callus formed with compact, better-mineralised trabeculae and signs of woven-to-lamellar remodelling. By day 28 the callus consisted predominantly of mature lamellar bone with restored architecture, although isolated dystrophic osteocytes persisted.&lt;/p&gt;&lt;p style="text-align: justify;"&gt;Conclusion. Combined metabolic correction substantially improves reparative osteogenesis under lead intoxication, bringing the morphological picture closer to physiological, yet not reaching the level of intact animals.&lt;/p&gt;</jats:p>