The comparative investigation of left ventricle papillary muscle arteries in different species.

Objective: To determine whether similar histologic findings exist in left ventricle papillary muscle arteries in different species and to elicit whether those animal hearts may be used as models for human heart in experimental studies related to papillary muscles.

Methods: We examined 360 samples taken from the tip, mid-portion and base of papillary muscles in 60 normal adult hearts (15 each from human, dog, sheep, goat). The samples were obtained from Dicle University and Kahramanmaras Sutcu Imam University, Turkey and the study was conducted in June-September 2004. Tissues were processed by routine histologic methods, stained with hematoxylin-eosin and van giesson, and later evaluated under a light microscope.

Results: While the values of human and dog heart resembled each other by means of left ventricle papillary muscle arteries, the hearts of sheep and goat were also found to be similar. The number of thin walled arteries increased from the tip (18%) to the base (48%), intermediate walled arteries decreased from the tip (56%) to the base (14%), thick walled arteries decreased from the tip (62%) to the mid-portion (38%). The differences among human and animals were not statistically significant in any group. We found that the thickness values of papillary muscle arterial walls at the tip, mid-portion and base varied from 4.86 microm to 107.7 microm in all species. The difference among values of human and animals was not significant statistically (p>0.05).

Conclusion: The values for arterial walls of tip, mid-portion and base of papillary muscles were similar between human and dog, sheep and goat. These morphologic findings in human and animal hearts of different species prove that anatomists, cardiologists, experimental investigators, pathologists and physiologists may benefit from the hearts of those animals as a good model to imitate the human heart in experiments concerning papillary muscles.