Table 3.
Transplantation of brown fat to study development of fat pads in rodents
| Ref. | Fat Graft | Transplantation Site | Animals (Fat graft → Host) | Observations |
|---|---|---|---|---|
| 87 | 1) Clusters of brown fat 2) Isolated brown preadipocytes 3) Isolated brown adipocytes |
1) Intramuscular 2,3) Under the kidney |
WT→ WT mice | 1) Formed fat pad. 2, 3) Did not form fat pad. |
| 88 | Brown fat (1–3 mg) | Subcutaneous | WT→ WT mice | Did not form fat pad. |
| 89 | 1, 2) Immature brown fat | 1) Into eye 2) Denervation of iris, then implanted into eye |
WT→ WT hamsters | 1) Initial vascularization and proliferation of unilocular cells. Innervation started at day 10, and reached 17% of the endogenous levels by 6 weeks. As number of adrenergic fibers increased, differentiation increased. 2) Denervation delayed appearance of normal brown fat to 20 days. |
| 90 | 1) Brown fat 2) White fat 3) Brown fat exposed to cold 4) Brown fat 5) White fat |
1,2) Under the kidney 3–5) none |
WT→ WT mice | 1) No innervation after 2 weeks. Increased cell size and lipid content. 2) No innervation after 2 weeks. Decreased cell size and lipid content 3) NS cell size. Decreased lipid content. Increased vascularization. |
| 91 | 1–4) Brown fat | 1–4) Under the kidney | 1)ob/ob or WT→ob/ob or WT 23µC for 5 wk 2)ob/ob or WT→WT 4µC for 5 wk 3)ob/ob or WT→ob/ob 33µC for 5 wk 4)ob/ob or WT→ob/ob or WT 4µC for 5 wk+23µC for 3 wk |
1, 3) Ambient temperature partially transformed lipid droplet size and mitochondrial structure to that of host. Very few innervations to adipocytes. 2) Cold temperature completely transformed size of lipid and mitochondrial structure to that of WT host. Innervation to both blood vessels and adipocytes. 4) Cold then ambient temperature still maintained complete transformation to that of WT host. Innervation to both vessels and adipocytes. |
| 92 | Brown fat | Under the kidney | ob/ob or WT→ob/ob or WT | Fatty acid composition of graft changed to that of host. |
Numbers 1), 2), 3), etc in each row correspond to the same group of animals for each study.
Abbreviations: NS: no statistically significant change in; wk: weeks; WT: wild-type.