Ecto-ATPases, Morphometry, and Heat Production Activity of Erythrocytes of Cartilaginous and Teleost Fishes of the Black Sea
摘要
The activity of ecto-ATPase and the erythrocyte size have been studied in two species of cartilaginous and ten species of bony fish; in addition, the heat-producing activity of the erythrocyte suspension was measured for black scorpionfish Scorpaena porcus and thornback ray Raja clavata. In cartilaginous fishes, the activity of ecto-ATPase of red blood cells (RBC) differs by 1.5 times: 3.1 nmol Pin/min/µL RBC in Raja clavata vs. 2.1 nmol Pin/min/µL RBC in Dasyatis pastinaca. The erythrocytes of teleost fish are characterized by a more significant variability in the activity of ecto-ATPase, which differs more than 60-fold: 6.4 nmol Pin/min/μL RBC in Scorpaena porcus vs. 0.1 nmol Pin/min/μL RBC in Spicara flexuosa and some other species. The erythrocyte size and ecto-ATPase activity have a direct relationship. When studying heat production of erythrocyte suspensions of the thornback ray and black scorpionfish, a significant increase in temperature in the experimental cell occurs when ATP has been added to the suspension of isolated cells (1 mg/mL). The erythrocytes of the thornback ray and black scorpionfish demonstrate different heat-generation dynamics: ∆T generated by thornback ray erythrocytes is almost half as much compared to that of black scorpionfish. In the erythrocyte suspension of the thornback ray, total duration of the heat-generation process to the maximum ∆T is almost four times shorter than that in the black scorpionfish. However, the process of temperature reduction in the black scorpionfish erythrocyte suspension occurred more than two times slower than that for the thornback ray. The ecto-ATPases of fish erythrocytes apparently function as a source of local heat generation on the erythrocyte surface; therefore, they can be deeply integrated into the functioning of the cell membrane and the entire blood flow in general.