Representative parameters of BM function in humans and mice
| Parameters . | Humans . | Mice . | Reference(s) . |
|---|---|---|---|
| Total weight of BM (relative to body mass) | 4%-5% | 1.5%-2% | 16-18, 73, 74 |
| Weight in standard individual | 3 kg | 0.4-0.5 g | 18, 73, 75 |
| Total volume BM | 1100-2100 cm3 | 0.35-0.4 cm3 | 73, 74, 76 |
| Total volume blood | 70-80 mL/kg | 85-95 mL/kg | 18, 77 |
| Blood volume in the BM (% of tissue volume) | ND | 15%-30% | 32; C.N.-A., unpublished data |
| Ratio cortical/trabecular bone | 80:20 | 65:35 | 37, 78 |
| Nucleated BM cells per kg body weight | (1.1-2.1) × 1010 | (1.1-1.8) × 1010 | 79, 80 |
| Total nucleated BM cells | (0.8-1.5) × 1012 | (2.8-5.2) × 108 | 79-81 |
| Cell production per day | |||
| Total | (4-5) × 1011 ([5-7] × 1010 cells per kg) | (0.5-1.5) × 109 ([2-6] × 1010 cells per kg) | 20 |
| RBCs | 2.2 × 1011 | (0.45-0.85) × 109* | 21 |
| Platelets | (1-1.75) × 1011 | (0.16-0.7) × 109* | 22 |
| Neutrophils | (0.45-1.2) × 1011 | (0.7-1.9) × 107 | 23, 82 |
| Major BM cavities (% of total BM content) | Lower limbs, 26%-38% | Vertebrae, 32%-52% | 16, 17, 80, 81, 83 |
| Vertebrae, 14%-28% | Lower limbs, 14%-20% | ||
| Pelvis, 16% | Pelvis, 25% | ||
| BM adipogenesis (% of BM volume) | 50%-70% (age 25) | 1%-2% in 12 wk old | 60, 84-86 |
| 18%-20% in 56 wk old (measured in proximal tibial metaphysis) | |||
| Number of HSCs (functional definition) | (28-112) × 106† | 11 200-22 400 | 87 |
| Myeloid:erythroid ratio | 3:1 | 1.7:1-2.3:1 | 73, 88, 89 |
| Parameters . | Humans . | Mice . | Reference(s) . |
|---|---|---|---|
| Total weight of BM (relative to body mass) | 4%-5% | 1.5%-2% | 16-18, 73, 74 |
| Weight in standard individual | 3 kg | 0.4-0.5 g | 18, 73, 75 |
| Total volume BM | 1100-2100 cm3 | 0.35-0.4 cm3 | 73, 74, 76 |
| Total volume blood | 70-80 mL/kg | 85-95 mL/kg | 18, 77 |
| Blood volume in the BM (% of tissue volume) | ND | 15%-30% | 32; C.N.-A., unpublished data |
| Ratio cortical/trabecular bone | 80:20 | 65:35 | 37, 78 |
| Nucleated BM cells per kg body weight | (1.1-2.1) × 1010 | (1.1-1.8) × 1010 | 79, 80 |
| Total nucleated BM cells | (0.8-1.5) × 1012 | (2.8-5.2) × 108 | 79-81 |
| Cell production per day | |||
| Total | (4-5) × 1011 ([5-7] × 1010 cells per kg) | (0.5-1.5) × 109 ([2-6] × 1010 cells per kg) | 20 |
| RBCs | 2.2 × 1011 | (0.45-0.85) × 109* | 21 |
| Platelets | (1-1.75) × 1011 | (0.16-0.7) × 109* | 22 |
| Neutrophils | (0.45-1.2) × 1011 | (0.7-1.9) × 107 | 23, 82 |
| Major BM cavities (% of total BM content) | Lower limbs, 26%-38% | Vertebrae, 32%-52% | 16, 17, 80, 81, 83 |
| Vertebrae, 14%-28% | Lower limbs, 14%-20% | ||
| Pelvis, 16% | Pelvis, 25% | ||
| BM adipogenesis (% of BM volume) | 50%-70% (age 25) | 1%-2% in 12 wk old | 60, 84-86 |
| 18%-20% in 56 wk old (measured in proximal tibial metaphysis) | |||
| Number of HSCs (functional definition) | (28-112) × 106† | 11 200-22 400 | 87 |
| Myeloid:erythroid ratio | 3:1 | 1.7:1-2.3:1 | 73, 88, 89 |
Published estimated values on BM composition and function. Values depicted have been in most cases obtained for, or adjusted to, a reference standard individual of 70 kg for humans and 25 g for mice.
HSC, hematopoietic stem cell; ND, not determined; RBC, red blood cell.
Rates of erythrocyte and platelet production in mice have been here estimated as described by Palis21 by using available data on the specific half-lives and total numbers in blood.
Reliable estimations of total HSC numbers in humans are lacking to date. As depicted, for most parameters presented, including weight and blood cell production, the ratio of values between mouse and human species falls approximately with a range of 2500 to 5000. The theoretical number of HSCs for the human system provided in this table has been estimated assuming that similar ratios would apply for proportional scaling of HSC content between species.