Relative ventricle mass and enzyme activities in the compact and spongy myocardial layers of three lamniform shark species
| . | . | . | . | Enzyme activity a at 20°C . | . | . | . | |||
|---|---|---|---|---|---|---|---|---|---|---|
| . | . | . | . | CS . | . | LDH . | . | |||
| Species (common name) . | Body mass (kg) . | Relative ventricle mass (% body mass) . | Relative compact myocardial tissue (% of ventricle) . | Compact . | Spongy * . | Compact . | Spongy . | |||
| Isurus oxyrinchus | 6 | ∼0.17 b,c | ∼36-40 b,d | 37.7 | 44.0 | 494 | 503 | |||
| (shortfin mako shark) | 26 | 39.9 | 42.8 | 487 | 495 | |||||
| 49 | 34.2 | 36.3 | 303 | 343 | ||||||
| Lamna ditropis | 127 | 0.18-0.20 c | ∼40 d | 34.5 | 38.0 | 306 | 312 | |||
| (salmon shark) | 136 | 31.6 | 32.7 | 409 | 428 | |||||
| Alopias vulpinus | 21 | −0.10-0.29 b | ∼36 b | 32.6 | 31.4 | 459 | 487 | |||
| (common thresher shark) | 34 | 25.2 | 31.7 | 421 | 499 | |||||
| 37 | 19.9 | 23.0 | 226 | 233 | ||||||
| 43 | 18.9 | 20.7 | 240 | 200 | ||||||
| . | . | . | . | Enzyme activity a at 20°C . | . | . | . | |||
|---|---|---|---|---|---|---|---|---|---|---|
| . | . | . | . | CS . | . | LDH . | . | |||
| Species (common name) . | Body mass (kg) . | Relative ventricle mass (% body mass) . | Relative compact myocardial tissue (% of ventricle) . | Compact . | Spongy * . | Compact . | Spongy . | |||
| Isurus oxyrinchus | 6 | ∼0.17 b,c | ∼36-40 b,d | 37.7 | 44.0 | 494 | 503 | |||
| (shortfin mako shark) | 26 | 39.9 | 42.8 | 487 | 495 | |||||
| 49 | 34.2 | 36.3 | 303 | 343 | ||||||
| Lamna ditropis | 127 | 0.18-0.20 c | ∼40 d | 34.5 | 38.0 | 306 | 312 | |||
| (salmon shark) | 136 | 31.6 | 32.7 | 409 | 428 | |||||
| Alopias vulpinus | 21 | −0.10-0.29 b | ∼36 b | 32.6 | 31.4 | 459 | 487 | |||
| (common thresher shark) | 34 | 25.2 | 31.7 | 421 | 499 | |||||
| 37 | 19.9 | 23.0 | 226 | 233 | ||||||
| 43 | 18.9 | 20.7 | 240 | 200 | ||||||
Enzyme activities are expressed as μmol substrate converted to product per min (IU) per g wet mass of tissue.
Data from Emery et al.(1985).
D. Bernal, N. C. Lai, W. Lowell, K. Dickson, C. Sepulveda and J. Graham,unpublished.
D. Bernal and J. Graham, unpublished.
Spongy myocardium CS activities are significantly higher(P<0.05) than in compact myocardium.