Anatomy of rodent and human livers: What are the differences?

Abstract

The size of the liver of terrestrial mammals obeys the allometric scaling law over a weight range of >3 ∗ 10. Since scaling reflects adaptive changes in size or scale among otherwise similar animals, we can expect to observe more similarities than differences between rodent and human livers. Obvious differences, such as the presence (rodents) or absence (humans) of lobation and the presence (mice, humans) or absence (rats) of a gallbladder, suggest qualitative differences between the livers of these species. After review, however, we conclude that these dissimilarities represent relatively small quantitative differences. The microarchitecture of the liver is very similar among mammalian species and best represented by the lobular concept, with the biggest difference present in the degree of connective tissue development in the portal tracts. Although larger mammals have larger lobules, increasing size of the liver is mainly accomplished by increasing the number of lobules. The increasing role of the hepatic artery in lobular perfusion of larger species is, perhaps, the most important and least known difference between small and large livers, because it profoundly affects not only interventions like liver transplantations, but also calculations of liver function.

Comparative Anatomical Study Between the Human and Swine Liver and Its Importance in Xenotransplantation

“…The gallbladder is situated in the visceral surface of the liver sidelong to the quadrate lobe [15]. Segments I, II and III form the left liver lobe, while segments IV, V, VI, VII and VIII form the right liver lobe (Figure 2) [11]. Both human and pig livers consist of sinister, dexter, quadrate and caudate lobes; because of the more lobular shape of the porcine liver, the sinister and dexter lobes are each divided into lateral and medial lobes.…”

“…Many investigations on medical treatment and surgical techniques have been applied to pigs; this is feasible due to their great structural and cellular compatibility with humans, making them perfect candidates for liver xenotransplantation [ 10 ]. Inspired by the comparative study between rodent and human livers by Kruepunga et al in 2019 [ 11 ], the purpose of this review is to compare anatomical elements of the liver in between the human and porcine cases to enhance the current knowledge based on the recent literature.…”

The hepatic innate immune response is lobe-specific in a murine model endotoxemia

“…In the human, the portal vein divides the liver into left and right perfusion areas. 45 Making direct comparisons between this perfusion pattern, and the murine portal anatomy described above is difficult. Finally, the hepatic artery contribution to lobar perfusion increases, and the portal contribution decreases, as the animal increases in size.…”

“…It is estimated that the portal contribution is 25% lower in men than in mice. 45 While important to note these differences, the fact remains that during the study of murine endotoxemia significant lobe-specific differences exist that must be accounted for during study design and sample collection.…”

Drug addiction: a curable mental disorder?

“…Accordingly, more studies are required by using optogenetic and chemogenetic approaches to identify novel brain areas that participate in drug addiction. It should be noted that neural circuit-related studies in animals are probably not translable to humans due to the great heterogeneity of brain anatomy between rodents and humans [88]. In addition, current techniques only allow us to stimulate one brain region at one time, which would limit the efficacy of brain stimulation.…”