Stereologic analysis of the density of the vascular network of the heart in hypoxia in laboratory rats

: The density of the myocardiac vascular network in 3-month-old female Wistar rats exposed to intermittent hypoxia was studied. The experimental rats were sacrificed immediately (1st experimental subgroup) or 4 days (2nd experimental subgroup) after the last exposition. The volume density was statistically highly significant in the animals of the 1st subgroup and significant in the rats of the 2nd subgroup. The highly significant rise in the volume density of the myocardiac vascular network could be explained by an acute stress effect, whereas the only significant increase in the second case indicates adaptability to stress.