The long-term objective is to ascertain the effects of disease [systemic (diabetes) and local (inflammation)] and chemotherapeutic treatments (ascorbate and minocycline) on collagen metabolism in gingiva, these two perturbations serving as models for understanding the deleterious effects of periodontal disease on oral tissues. Towards this objective, sophisticated methodology will be used to """"""""dissect"""""""" the effect of these diseases (and treatments) on different components of collagen metabolism, including synthesis, intracellular procollagen degradation, production (the amount of collagen actually formed in the tissue), accretion, and degradation. Until recently, methods were either too tedious or inexact to allow for such determinations, but the pool-expansion approach corrects for these deficiencies. This method involves the injection of excess unlabeled amino acid (proline) along with the radiolabeled precursor ([3H]proline) and accomplishes the following: maintains a constant (or measurable) source of radiolabeled precursor; eliminates differences in proline pools between different tissues and between one tissue under different states; and allows for a calculation of the pivotal component of collagen metabolism, namely, collagen production.
The specific aims are as follows: (1) fractional rate of collagen production (and synthesis); (2) intracellular procollagen degradation: extent, relationship to collagen hydroxylation, and characterization of degradation products; (3) effects on the components of collagen metabolism in streptozotocin-induced diabetic rats; (4) in ascorbate and minocycline-treated diabetic rats; and (5) in antigen-antibody-induced inflamed gingiva of control and ascorbate- and minocycline-treated rats. The methods for achieving these objectives are as follows: fractional rate of collagen production--specific radioactivity of [3H]hydroxyproline in the TCA-insoluble fractions of gingiva/specific radioactivity of tissue free [3H]proline; intracellular procollagen degradation--the amount of TCA-soluble [3H]hydroxyproline/total [3H]hydroxyproline in the tissue; relationship to hydroxylation--the % of hydroxyproline/hydroxyproline + proline, unlabeled and radiolabeled, in isolated alpha chains of gingival collagen; characterization of degradation products--column chromatography of [3H]hydroxyproline-containing material in TCA-soluble fractions. Overall, this should be the most definitive study of collagen metabolism in gingiva of healthy, diseased, and chemotherapeutically-treated diseased rats.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Research Project (R01)
Project #
5R01DE003318-15
Application #
3218853
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
1978-03-01
Project End
1988-02-29
Budget Start
1986-03-01
Budget End
1987-02-28
Support Year
15
Fiscal Year
1986
Total Cost
Indirect Cost
Name
University of Southern California
Department
Type
Schools of Dentistry/Oral Hygn
DUNS #
041544081
City
Los Angeles
State
CA
Country
United States
Zip Code
90033
Craig, R G; Yu, Z; Xu, L et al. (1998) A chemically modified tetracycline inhibits streptozotocin-induced diabetic depression of skin collagen synthesis and steady-state type I procollagen mRNA. Biochim Biophys Acta 1402:250-60
Schneir, M; Ramamurthy, N; Golub, L (1990) Minocycline-treatment of diabetic rats normalizes skin collagen production and mass: possible causative mechanisms. Matrix 10:112-23
Schneir, M; Imberman, M; Ramamurthy, N et al. (1988) Streptozotocin-induced diabetes and the rat periodontium: decreased relative collagen production. Coll Relat Res 8:221-32
Imberman, M; Ramamurthy, N; Golub, L et al. (1986) A reassessment of collagen half-life in rat periodontal tissues: application of the pool-expansion approach. J Periodontal Res 21:396-402
Schneir, M; Imberman, M; Ramamurthy, N et al. (1986) The in vivo fractional rate of gingival collagen production in non-diabetic and diabetic rats. Application of a novel approach for quantification-pool expansion. J Periodontal Res 21:56-63
Leung, M K; Folkes, G A; Ramamurthy, N S et al. (1986) Diabetes stimulates procollagen degradation in rat tendon in vitro. Biochim Biophys Acta 880:147-52
Ramamurthy, N S; Greenwald, R A; Schneir, M et al. (1985) The effect of alloxan diabetes on prolyl and lysyl hydroxylase activity in uninflamed and inflamed rat gingiva. Arch Oral Biol 30:679-83
Schneir, M; Ramamurthy, N; Golub, L (1985) Dietary ascorbic acid normalizes diabetes-induced underhydroxylation of nascent type I collagen molecules. Coll Relat Res 5:415-22