Coronary artery distribution in Macaca fascicularis (Cynomolgus).

The studies were performed using stereomicroscopic dissection, and light microscopy examination on hearts of healthy and fertile non-human primates (Macaca fascicularis) of both sexes. The results indicate that the anatomy of the coronary arteries offers points of similarity as well as departure from humans. The blood supply to the hearts was by left (LCA) and right (RCA) coronary arteries. The LCA averaged 1.78 +/- 0.29 (SD) mm (range 1.40-2.40 mm) in external diameter at its origin, and 4.34 +/- 1.29 (SD) mm (range 1.8-6.5 mm) in length. It usually terminated by dividing into a left anterior descending artery (LAD) and the circumflex branch (CXA). The CXA branch coursed along the left part of the atrioventricular groove and gave off a varying number of branches to the left ventricle and atrium along its course. It averaged 1.14 +/- 0.30 (SD) mm (range 0.70-1.70 mm) in external diameter at its origin. The LAD averaged 1.28 +/- 0.25 (SD) mm (range 0.90 +/- 1.80 mm) in external diameter at its origin. In 73% cases the LAD continued over the apex to course dorsally in the posterior interventricular groove, and gave off a varying number of diagonal and septal branches. The RCA arose from the right aortic sinus and coursed along the right part of the atrioventricular groove and averaged 0.94 +/- 0.15 (SD) mm (range 0.70-1.20 mm) in external diameter at its origin. The posterior descending coronary artery (PDCA) arose from the LCA in 55% of the cases, and from the RCA in 45%. Myocardial bridges (MB) were present in 54% of the hearts and over the LCA branches exclusively. The average length of all MB was 5.68 +/- 3.31 (SD) mm (range 2.4-11.5 mm). The coronary arteries of Macaca fascicularis are medium sized muscular arteries with well developed tunics intima, media and adventitia, and so resemble human arteries more closely than the dog. Therefore, we suggest this primate species might be a useful model for physiological studies on the coronary circulation.

[Coronary arteries in the Macaca fascicularis monkey]. / Koronarne arterije majmuna Macacus fascicularis.

The coronary arterial epicardial network in the monkey Macaca fascicularis was studied. The study concerned 11 hearts of healthy and fertile animals of both sexes. The morphological and morphometric results of the studies performed by microdissection revealed that: In all examined cases of the Macaca fascicularis the heart was supplied by blood through the left and right coronary arteries. The left coronary artery had a larger external diameter (1.2 mm-2.5 mm, average 1.8 mm) than the right one (0.7 mm-1.2 mm, average 0.9 mm). The left coronary artery, with the average length of 4.3 mm (1.8 mm-6.5 mm), usually (82%) ended by bifurcation in to the anterior interventricular and the circumflex branch, and less frequently (18%) by trifurcation forming, in this way, another branch: the left marginal branch. The anterior interventricular branch had the larger external diameter (0.9 mm-1.7 mm, average 1.3 mm) than the circumflex one (0.7 mm-1.7 mm, average 1.1 mm). Most frequently (73%) it could be traced along the diaphragmatic cardiac surface. The circumflex branch usually (73%) terminated as the posterior interventricular branch, and less frequently (9%) as one of the right posterior ventricular branches. The long type of the right coronary artery was observed in 45% of the cases. The presence of the myocardial bridges over the branches of the left coronary artery was found in 54% of the examined hearts. The great resemblance between the Macaca fascicularis subepicardial network with the corresponding one in humans suggest that Macacus fascicularis is a suitable experimental animal for functional studies of the cardiovascular system.

A morphological study of the size of the vascular compartment of the carotid body in a non-human primate (Cercopithecus ethiopus), and a comparison with the cat and rat.

The carotid bodies from 5 adult non-human primates (mean body weight 2.9 kg) were perfusion-fixed at normal arterial blood pressure with 3% phosphate-buffered glutaraldehyde. Serial 5-microns sections were cut, stained, and, using an interactive image analysis system, determinations were made of the volumes of the carotid body and of its vascular and extravascular compartments. The total volume of the carotid body was, on average 0.21 mm3, the total vascular volume contributing 9.7%. The small vessels (5-12 microns diameter) comprised 5.4% of the total volume of the carotid body, or about 56% of the vascular compartment; these estimates were similar to values obtained for the cat and rat. The mean small vessel endothelial area, per unit of extravascular volume (which is assumed to consist largely of type 1 and 2 cells) was 61.8 mm-1 in the primate and 69.7 mm-1 in the cat. A value was not available for the rat. Estimates of the carotid body tissue specific blood flow were 31, 61 and 104 ml/min/100 g organ tissue in the primate, cat and rat, respectively. It was emphasised that these values were not to be confused with estimates of carotid body specific blood flow based on values for total organ blood flow and the dissected weight of the organ.