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Indexed/Abstracted in: BIOSIS Previews, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,6
Online ISSN 1827-1898
Gersak B., Trobec R.*, Krisch I.**
From the Department of Cardiovascular Surgery, Medical Centre Ljubljana
* Jozef Stefan Institute, Ljubljana
** LEK Pharmaceutical Company, Ljubljana, Slovenia
Background. The contraction/relaxation response of thoracic aortal rings clamped with two clamping pressures to KCl, noradrenaline and carbachol was studied.
Methods. Clamp A had the tip pressure PA=0.60 N/mm2 and clamp B PB=5.16 N/mm2. In fifteen Wistar albino rats, weighing 328±19 g (mean ±SD) the thoracic aorta was occluded for 15 minutes and then three vascular rings (2 mm wide) were excised. The proximal unclamped ring served as a control. From distal rings the diameter of the aorta was calculated from their circumference 1.61±0.01 mm (n=15, dmin=1.51 mm, dmax=1.70 mm). The rings were challenged with cumulative additions of KCl (10-80 mmol/l) to measure the contraction. Then cumulative relaxation to carbachol (0.01-100 µmol/l) as a response to noradrenaline precontraction (0.1 µmol/l) was determined.
Results. A significant loss (p<0.05) of vascular relaxation in all clamped rings (clamped with PA and PB clamping pressures) was seen. No significant differences (p>0.05) were observed for contraction between clamped and control rings clamped with clamp A, however the rings clamped with clamp B showed a significant reduction in contraction (p<0.05). No significant differences were seen from control rings between groups A and B (p>0.05), or from clamped rings between groups A and B (p>0.05) for both the contraction and relaxation part of experiments.
Conclusions. Endothelial vascular layers are much more susceptible to pressure injuries than was previously believed.