Physiological analysis of the lymphatic system in the eastern painted turtle (Chrysemys picta picta)

Examination into the anuran lymphatic system has led to a comprehensive understanding of lymphatics, including the importance of synchrony in fluid-balance maintenance. However, little research has been conducted on the lymphatics of turtles and other reptilian vertebrates. Using pressure-peak recordings created through cannulation of both lymph hearts of the eastern painted turtle, Chrysemys picta picta (Schneider, 1783), the lymph heart contraction rate was verified and the interbeat interval patterns were examined using Poincaré plots. The lymph heart beating rate was determined to be 38.2 beats·min–1with a mean pulse pressure of 2.40 ± 1.44 mm Hg (1 mm Hg at 0 °C = 133.3224 Pa). Poincaré plots are useful in displaying nonlinear sequential data and are often given descriptive names related to the overall pattern. The Poincaré plot resembled a garden hose nozzle spray, indicating a large variability in interbeat time intervals with periods of multiple-beat patterns. The degree of bilateral lymph heart synchrony was determined in the turtle using the mean time difference between right and left lymph heart systoles. Results show that chelonian lymph hearts do in fact beat in synchrony, with over 50% of contractions occurring within 100 ms of each other. This indicates shared neuronal control and may suggest an energetic advantage to fluid homeostasis.

Synchrony in the amphibian lymphatic system: evidence for bilateral posterior lymph heart synchrony and cardiac–lymphatic synchrony inRana catesbeianaandBufo marinus

Early investigations into amphibian lymph heart function established that lymph heart contractions were synchronous with neither the systemic heart, nor the lungs, nor each other. However, the present study concludes that there is synchronization between the cardiac heart and the lymph hearts and that the posterior lymph hearts in both Rana catesbeiana Shaw, 1802 and Bufo marinus (L., 1758) beat synchronously as well. Pressure peaks were recorded through cannulation of the ischiatic artery and each posterior lymph heart and subsequently analyzed to determine the time differences between arterial diastole and lymph heart systole or between two bilateral lymph heart systoles. Results show that there is clear synchronization between the lymph heart systoles of two bilateral posterior lymph hearts. This lymph heart synchrony is further supported by using Poincaré plot analysis to visually compare the lymph heart inter-beats. Cardiac heart and lymph heart contractions also show a degree of synchronization, even though the lymph hearts beat up to three times as fast as the cardiac heart. These results support the conclusion that synchrony is characteristic of the anuran lymphatic system and that synchronization of the cardiac heart and the lymph hearts could impart an energetic advantage that benefits fluid homeostatic mechanisms.