Collagen metabolism of skin and periodontal membrane in the squirrel monkey

Abstract

Glucocorticoid administration is known to have an inhibitive effect on collagen activity. It can be assumed that this effect also takes place in the periodontal membrane (PDM). The purpose of the present investigation was to investigate whether this reduction in PDM collagen activity is reflected in the autoradiographic grain count score. Ten young adult male squirrel monkeys were injected with JH-proline and sacrificed 48 hours after the injection. Five of the animals were injected with Ultracortenole 72 and 24 hours prior to sacrifice. Grain count analysis was carried out on autoradiographs from sections of premolars, and skin biopsies were analyzed with respect to NaCl soluble 3H-activity. In the skin the activity found in the soluble fraction was lower in the Ultracortenol-treated than in the control animals (319 f 56 cpmlmg compared to 629 f 70 cpmlmg). Autoradiographic grain counts were carried out over the periodontal membrane, the average number of grains was lower in the Ultracortenolinjected than in the control animals. This was true for all areas of the periodontal membrane examined. The significance of the autoradiographic grain count score from the PDM following 3H-proline injection is discussed. It is concluded that this parameter is ieasonably, valid for the assessment of the PDM collagen activity.In the last decades considerable research activity has been focused on collagen metabolism, and in particular the collagen activity in skin has been thoroughly investigated. Tracer studies on experimental animals have revealed that the rate of renewal is dependent on the age of the animals; the formation of new collagen being more rapid in young than in old animals (Nimni, G u i a 6 Bavetfa 1965). The collagen activity is also influenced by other factors, e. g. glucocorticoids depress the rate of formation (Kowalewski 1966, Laitinen 1967.Attempts have also been made to analyze collagen synthesis in the periodontal membrane (PDM). Such analyses present technical obstacles since the necessary analyses for biochemical assay of the PDM, particularly in smaller animals, are difficult to apply.The only possibility for assessment of the PDM collagen activity has hitherto been autoradiography following injection of 3H-proline. Stallard (1963), C a r n e i r o (1965), and C a r n e i r o 6 Moraes (1965) demonstrated collagen synthesis in the PDM autoradiographically after injection of labeled proline or glycine. S k o u g a a r d , Levy 6Simpson (1970) found by the same method that the activity in PDM was extremely high, approximately eight times higher than in skin and twice as high as in gingiva. Furthermore it was dem-

Histochemical Examination on Periodontal Tissues of Klotho-Deficient Mice Fed With Phosphate-Insufficient Diet

“…Indeed, there are several reports on the continuous and fast turnover of periodontal collagen in PDL. 1,[3][4][5][6][7][8][9] Aging is one physiological factor for chronological alteration of morphology and function on the periodontal tissue. Investigations on senescent rats, marmosets, and human verified that the periodontal tissue showed atrophic and degenerative changes on the histology-narrowed periodontal spaces, irregularly oriented periodontal fibers, and so forth.…”

Autoradiographic study of 3H‐proline incorporation by rat periodontal ligament, gingival connective tissue and dental pulp

“…Tritiated proline incorporation measured by autoradiography is generally considered to signify a continuous coUagen synthesis in connective tissues, though some of ^H-proline might be incorporated into proteins other than collagen (Stallard 1953, Carneiro & Moraes 1965, Cameiro & Leblond 1966, Skougaard, Frandsen & Baker 1970. Skougaard and Levy (1971) stated that collagen metabolism could be evaluated by assaying the specific activity of labeled hydroxyproline following administration of labeled pro- line.…”

Effects of lathyrism on mouse molar migration

“…Because lathyrism does not affect tropocollagen synthesis but disturbs the aggregation of newly formed molecules (Levene 1973), it was considered that tissues with a higher turnover of collagen were more susceptible to the effects of the disease. The periodontal ligament has a high turnover of collagen (Skougaard, Frandsen & Baker 1970, Kameyama 1975, and there is evidence that a rate differential exists along the length of the ligament (Rippin 1976, Minkoff & Engstrom 1979. Minkoff and Engstrom (1979) have radioautographically determined that the labelled protein halflives for the dentogingival (25 days) and transseptal fibres (8.4 days) are greater than other collagen fibres of the 40-day-old mouse periodontal hgament (5-7 days).…”