| Full text | |
| Author(s): |
Filogonio, Renato
[1]
;
Dubansky, Benjamin D.
[2]
;
Dubansky, Brooke H.
[3]
;
Wang, Tobias
[4]
;
Elsey, Ruth M.
[5]
;
Leite, Cleo A. C.
[1]
;
Crossley, II, Dane A.
Total Authors: 7
|
| Affiliation: | [1] Univ Fed Sao Carlos, Dept Physiol Sci, BR-13565905 Sao Carlos, SP - Brazil
[2] II, Univ North Texas, Dept Biol Sci, Dev Integrat Biol Cluster, Denton, TX 76203 - USA
[3] Tarleton State Univ, Dept Med Lab Sci & Publ Hlth, Ft Worth, TX - USA
[4] Aarhus Univ, Dept Biosci, Sect Zoophysiol, DK-8000 Aarhus C - Denmark
[5] Louisiana Dept Wildlife & Fisheries, Grand Chenier, LA 70643 - USA
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | JOURNAL OF COMPARATIVE PHYSIOLOGY B-BIOCHEMICAL SYSTEMIC AND ENVIRONMENTAL; v. 191, n. 3 FEB 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
Arterial wall tension increases with luminal radius and arterial pressure. Hence, as body mass (M-b) increases, associated increases in radius induces larger tension. Thus, it could be predicted that high tension would increase the potential for rupture of the arterial wall. Studies on mammals have focused on systemic arteries and have shown that arterial wall thickness increases with M-b and normalizes tension. Reptiles are good models to study scaling because some species exhibit large body size range associated with growth, thus, allowing for ontogenetic comparisons. We used post hatch American alligators, Alligator mississippiensis, ranging from 0.12 to 6.80 kg (similar to 60-fold) to investigate how both the right aortic arch (RAo) and the left pulmonary artery (LPA) change with M-b. We tested two possibilities: (i) wall thickness increases with M-b and normalizes wall tension, such that stress (stress = tension/thickness) remains unchanged; (ii) collagen content scales with M-b and increases arterial strength. We measured heart rate and systolic and mean pressures from both systemic and pulmonary circulations in anesthetized animals. Once stabilized alligators were injected with adrenaline to induce a physiologically relevant increase in pressure. Heart rate decreased and systemic pressures increased with M-b; pulmonary pressures remained unchanged. Both the RAo and LPA were fixed under physiological hydrostatic pressures and displayed larger radius, wall tension and thickness as M-b increased, thus, stress was independent from M-b; relative collagen content was unchanged. We conclude that increased wall thickness normalizes tension and reduces the chances of arterial walls rupturing in large alligators. (AU) | |
| FAPESP's process: | 16/20158-6 - Cardiovascular morpho-functional adaptations for allometric scaling of arterial blood pressures to body mass in reptiles |
| Grantee: | Renato Filogonio |
| Support Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 18/05035-0 - Cardiovascular regulation in Squamates: validation of the decerebrated rattlesnake model for studies on regulatory processes of the cardiovascular system |
| Grantee: | Cléo Alcantara Costa Leite |
| Support Opportunities: | Regular Research Grants |