Area of Science:

• Parasitology
• Amphibian physiology
• Capillary dynamics

Background:

• Lung flukes (Hematoloechus sp.) are common parasites in amphibians.
• Rana pipiens is a key model organism for capillary physiology research.
• Understanding host-parasite interactions is crucial for ecological and physiological studies.

Purpose of the Study:

• To investigate the impact of Hematoloechus sp. (H) infection on systemic and capillary variables in Rana pipiens.
• To identify physiological changes associated with H attachment and non-attachment.
• To explore the symbiotic relationship between H and its amphibian host.

Main Methods:

• Prospective, descriptive study design.
• Measurement of 38 descriptive, cardiovascular, and immunological variables in pithed Rana pipiens.
• Grouping based on Hematoloechus attachment status: No H, H Not Att, and H Att.

Main Results:

• 18 out of 38 variables changed significantly with H infection.
• Observed changes include weight loss, elevated immune cells, altered heart rate variability, faster coagulation, lower hematocrit, and fluid accumulation.
• Significant differences in hydraulic conductivity (Lp) and seasonal adaptation of osmotic pressure (σ(πc-πi)) were noted.
• Pro- and anti-inflammatory phases and increased capillary wall tensile strength were revealed.

Conclusions:

• Hematoloechus sp. infection significantly impacts Rana pipiens physiology, affecting both systemic and capillary functions.
• The host-parasite interaction represents a natural symbiosis, offering advantages like reduced edema for the host and a food source for the parasite.
• Host weight loss due to H attachment poses a long-term challenge for the parasite.
• The study enhances Rana pipiens as a model for physiological and capillary research, with potential clinical applications in inflammation and stroke.