Functional and morphological changes in the dermis of pig skin following surgery and x-irradiation

Thesis

The functional status of normal and traumatised pig flank skin was investigated using an isotope clearance technique. The isotope was removed from the site of intradermal injection by two clearance exponents, which were shown to result from clearance by vessels in the papillary (fast exponent) and reticular (slow) dermis. In ageing skin the slow exponent clearance time lengthened as the reticular dermis thickened. There were also age related decreases in the vascular density. However, minimal changes occurred in the fast clearance exponent, the papillary dermal thickness or its vascular density. Isotope clearance is thus shown to be related to both vascular density and blood flow velocity.

Vascular function in the distal region of skin flaps showed changes for 14 days after surgery. Initially isotope clearance was slower than in normal skin but became faster when new vascular connections with the surrounding skin developed; dual isotope labelling technique indicated similar functional changes and an increased red cell volume. Functional changes were correlated with varying dermal thickness and vascular densities. Skin flaps were functionally 'normal' from 21 to 365 days.

X-irradiation of skin with a single dose or 6f/18 days caused functional impairment at week 12 which was related to visible skin reactions and morphological changes. Faster clearance was recorded initially after 30f/39 days but there was no subsequent impairment. In all groups normal clearance values were related to similar vascular densities in atrophic skin, 39 to 104 weeks after irradiation.

The viable length of flaps raised from irradiated skin was less than 'control' flaps. When clearance was impaired before surgery no further post-operative impairment occurred in the distal region of "irradiated" flaps. Clearance rates were the same in "irradiated" and 'control' flaps from 7 to 14 days post-operatively. On day 14 irradiated flaps were functionally similar to normal skin before surgery.

Authors: Young, C; Young, Caroline Mary Ann

• Publication date: 1978
• DOI: 10.5287/ora-dpgjdgj1y
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Subjects: Irradiation; Skin; Effect of radiation on; Blood-vessels; Isotopes