Comparison of In Vitro and In Situ Methods for Studying Lipolysis
Table 1
Advantages and limitations of some experimental methods for studying lipolysis.
Method
Advantages
Limitations
Culture of preadipocyte cell lines and differentiated stroma-vascular cells
Provides abundant supply of homogeneous cells Suitable for screening agents for their possible lipolytic or antilipolytic activities Appropriate for long-term in vitro studies Suitable for studying molecular mechanisms and transcription factors involved in lipolysis process
It takes several days until the cells become ready for study The cells may not fully differentiate to adipocytes Differentiation capacity decreases with increasing number of passages Excludes nervous system and endocrine system effects, therefore results may not fully reflect in vivo condition Glycerol reagent should be highly sensitive
Primary culture of adipocyte
Most of isolated adipocytes are fully differentiated A rapid method for testing acute effect of compounds Suitable for screening agents for their possible lipolytic or antilipolytic activities Comparative use of adipocytes from different depots
Need to high n number to resolve interindividual variations Need for enzymatic digestion Loss of hormone sensitivity and gene expression in long-term culture High variability in results obtained from freshly isolated cells Excludes nervous system and endocrine system effects Glycerol reagent should be highly sensitive
Organ culture of adipose tissue
Preserves extracellular matrix and paracrine interactions Good correlation with in vivo studies Useful for chronic lipolysis studies Suitable for assessing the long-term regulation of gen involved in the lipolysis pathways Comparative use of adipocytes from different depots
Presence of multiple cell types in tissue complicates interpretation of molecular mechanisms of tested drug Excludes nervous system and endocrine system effects
Microdialysis of adipose tissue
Preserves extracellular matrix and paracrine interactions Preserves nervous system and endocrine system effects Enables continuous monitoring of lipolysis Allows study of adipose tissue response during systemic drug administration
Its application on human is restricted to subcutaneous fat depot It is time consuming and uncomfortable for the patients