Purpose. To determine the indicators of portal hemodynamics in laboratory rats of different genders and ages based on the features of ultrasound scanning of the portal vein.
 Materials and methods. The study was conducted on 60 mongrel rats of both sexes weighing 120-270 g. The first group included 20 rats aged 1 month, the second – 20 rats aged 6-12 months and the third – 20 rats aged more than 18-24 months. The study of qualitative and quantitative indicators of portal hemodynamics was performed using ultrasound scanners with zoletil-xylazine anesthesia. Statistical analysis was performed using the application package Statistica 13.0 (StatSoft, USA).
 Results. The spectrum of blood flow in the portal vein of rats was unidirectional (monophasic), located above or below the isoline, with oscillations of the curve having a relationship with respiration. A clear dependence of blood flow fluctuations in the portal vein on cardiac activity has not been established. The diameter (by 15.4%, R= 0.64), the cross-sectional area (by 40%, R=0.68) and the maximum linear velocity of blood flow (by 1.2%, R=-0.09) in the portal vein increased with an increase in the age of the animals. The minimum linear velocity of blood flow decreased (by 32.2%, R =-0.05), which indicated an increase in the systolic-diastolic coefficient (an increase in the pulsativity of the flow). The indicator of the volumetric blood flow rate in the portal vein increased by 11.1% (R=0.06), and in relation to body weight decreased in elderly animals (by 11.5%, R=-0.05).
 Conclusion. A moderate increase in volumetric blood flow in the portal vein (by 11.1%) with a pronounced increase in body weight (by 34.9%) was found with an increase in the age of animals. The perspective of further research is to study the functional reserve of the liver in the age aspect.