Identification of connective tissue components in healing rat gingiva

Abstract

– The aim of the study was to examine connective tissue fiber organization during healing of an incisional wound in rat molar gingiva. Forty rats 50 days old were divided into 10 experimental groups each comprising four animals. Following interdental incisions, healing periods of 11‐20 days, and then 3H‐proline injection, the animals were sacrificed and specimens prepared for light microscopy, autoradiography, and transmission electron microscopy. Isotope labeling with 3H‐proline occurred over newly formed collagen in the path of incision, while preexisting tissue was unlabeled. Ultrastructurally, preexisting and new tissue were identified by measurement of collagen fibril thickness. The spatial relationship between new and remaining fibrous tissue in the transitional zone suggests that reunion is established by side‐by‐side alignment of new and severed fibrils.

Collagen fiber reunion in wound repair: transmission electron microscopic study of rat gingiva

“…This inference is based on previous observations of invading cells from light microscopy (7). It can, however, be argued that cell identification on the basis of position in the tissue is rather speculative in this context, especially since mesiodistal width of acellular segments is not a constant feature (8).…”

“…However, with few exceptions, tione of the numerous thin sections from the transitional zone exhibited a fibrillar relationship which could be interpreted as linkage of new and preexisting fibrils at the molecular level. For practical purposes,, only 40 randomly selected niigrographs were used for measurements of fibrillar conipotients, primarily to verify accurate tissue identification (8). Apart froro minor numerical differences without any significance, the tissue examined in the present specimens corresponded to "transitional connective tissue" described previously (8).…”

“…The site tissue segmetits attached to tooth, the process of reunion has previously been tentatively of reattachment takes place as a result of located on the basis of accumulation of inreunion of newly formed and preexisting vading fibroblasts, acellularity of preexisting connective tissue within 1-2 wk (5,6). tissue, tissue differentiation by various stains Although at an unpredictable frequency and and fluorescent dyes and of variation of fibril extent, severed tissue may take on a cellfree diameter in the connective tissue components appearance following injury (5)(6)(7)(8). After 3^ (7-9).…”

Effect of doxycycline on surgically induced osteoclast recruitment in the rat

“…However, following surgery, on-bone osteoclasts were identified not only at the periodontal ligament aspect (200 \xm) of the crest, but also palatally and far beyond the area scheduled for examination (200 \mi). The spatial relationship of osteoclasts occurring under the flap hardly contributes to elucidate the origin of these cells, either extraskeletal or local (14,18,19). The delay of first appearing osteoclasts, however, seems to indicate that doxycycline influences cellular events prior to osteoclastic bone resorption, e.g.…”

“…The number of experimental animals was linaited. The rats used for previous (9,19) and the present experiments were uniform as to biologic parameters, e.g. age, weight, sex, genetics, as well as tissue reactions.…”