[Capillaries of the myocardium of Lama (Lama glama)].
The heart of 12 adult llamas, one female and 11 males, 2-7 years of age, was studied gross-anatomically (absolute and relative heart weight) and microscopic-anatomically (left and right ventricular wall, left auricle). Comparing the 9 younger animals (2-3 years old) with the 3 older llamas (5-7 years old) a significant increase of the absolute heart weight and of the number of capillaries per mm2 and a significant decrease of the intercapillary distance in the left ventricular wall was found. This results in an increase of capillarity in the studied heart regions (5.5% compared to 6.9%). The simultaneous increase of the capillary-to-myocyte-ratios from 0.9 to 1.1 shows a significant correlation to the cross-sectional area of the myocytes (r = 0.79) and an also significant but negative correlation to the number of myocytes per mm2 (r = -0.82). In both groups the cross-sectional area of the myocytes and their diameter differs significantly in the three regions of the heart (left ventricular wall--214 micron 2 resp. 17.5 microns; right ventricular wall--156 micron 2 resp. 15.5 microns; left auricle--96 micron 2 resp. 11.5 microns). It is to be supposed, that the morphological conditions of the cardiac vascular supply of llamas living in an altitude of 4000 m are improving with age.
Hünigen
H
H
Institut für Veterinär-Anatomie, Fachbereich Veterinärmedizin, Freie Universität Berlin, Germany. hunigenh@zedat.fu-berlin.de
Butendieck
E
E
Berg
R
R
D000367:Age Factors; D000818:Animals; D002161:Camelids, New World / Q000033:anatomy & histology*; D002196:Capillaries / Q000254:growth & development; D003331:Coronary Vessels / Q000033:anatomy & histology* / Q000254:growth & development; D005260:Female; D006352:Heart Ventricles / Q000033:anatomy & histology*; D008297:Male; D009206:Myocardium / Q000166:cytology* / Q000648:ultrastructure