For diagnostic purposes, liver enzymes are usually classified into hepatocellular and cholestatic. These two groups of equine liver-specific enzymes include sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), γ-glutamyl transferase (GGT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP). SDH and GLDH mostly reflect hepatocellular injury and cholestasis, while GGT expresses high values in biliary necrosis or hyperplasia. Likewise, AST, LDH, and ALP also reflect hepatocellular and biliary disease, but these enzymes are not liver specific. From the clinical point of view of the course of liver or biliary disease, AST and ALP are indicative of chronic disease, whereas SDH, GGT, and GLDH indicate an acute course. The patterns of enzymatic changes at the blood level are associated with different types of liver pathologies (infectious, inflammatory, metabolic, toxic, etc.). Increases in hepatocellular versus biliary enzyme activities are indicative of a particular process. There are different ways to diagnose alterations at the hepatic level. These include the evaluation of abnormalities in the predominant pattern of hepatocellular versus cholestatic enzyme abnormalities, the mild, moderate, or marked (5–10-fold or >10-fold) increase in enzyme abnormality concerning the upper limit of the reference range, the evolution over time (increase or decrease) and the course of the abnormality (acute or chronic).

This study was conducted on two rabbit lines divergently selected for intramuscular fat (IMF) content in the Longissimus thoracis et lumborum (LTL) muscle. The aim was to estimate the direct response to selection for IMF after 10 generations, and the correlated responses in carcass quality traits, meat fatty acid content, liver fat and its fatty acid content, and in plasma metabolic markers related to liver metabolism. Selection for IMF content was successful, showing a direct response equivalent to 3.8 SD of the trait after 10 generations. The high-IMF line (H) showed a greater dissectible fat percentage than the low-IMF line (L), with a relevant difference (D_H-L = 0.63%, P_r = 1). No difference was found in liver fat content (D_H-L = −0.04, P₀ = 0.62). The fatty acid content of both LTL muscle and liver was modified after selection. The LTL muscle had greater saturated (SFA; D_H-L = 5.05, P_r = 1) and monounsaturated fatty acids (MUFA; D_H-L = 5.04, P_r = 1) contents in the H line than in the L line. No relevant difference was found in polyunsaturated fatty acids content (PUFA; P_r = 0.05); however, greater amounts of C18:2n6 (D_H-L = 3.03, P_r = 1) and C18:3n3 (D_H-L = 0.56, P_r = 1) were found in the H than in the L line. The liver presented greater MUFA (D_H-L = 1.46) and lower PUFA (D_H-L = −1.46) contents in the H than in the L line, but the difference was only relevant for MUFA (P_r = 0.86). The odd-chain saturated fatty acids C15:0 and C17:0 were more abundant in the liver of the L line than in the liver of the H line (D_H-L = −0.04, P_r = 0.98 for C15:0; D_H-L = −0.09, P_r = 0.92 for C17:0). Greater concentrations of plasma triglycerides (D_H-L = −34) and cholesterol (D_H-L = −3.85) were found in the L than in the H line, together with greater plasma concentration of bile acids (D_H-L = −2.13). Nonetheless, the difference was only relevant for triglycerides (P_r = 0.98).

In recent years, several studies have been conducted on Muse cells mainly due to their pluripotency, high tolerance to stress, self-renewal capacity, ability to repair DNA damage and not being tumoral. Additionally, since these stem cells can be isolated from different tissues in the adult organism, obtaining them is not considered an ethical problem, providing an advantage over embryonic stem cells. Regarding their therapeutic potential, few studies have reported clinical applications in the treatment of different diseases, such as aortic aneurysm and chondral injuries in the mouse or acute myocardial infarction in the swine, rabbit, sheep and in humans. This review aims to describe the characterization of Muse cells, show their biological characteristics, explain the differences between Muse cells and mesenchymal stem cells, and present their contribution to the treatment of some diseases.