Abstract:

BACKGROUND: Intervertebral disc degeneration accompanies by alterations in tissue structure and component. The component changes of intervertebral disc degeneration can be displayed in different colors when applying various stains for successive counterstaining. This method exhibits detectable changes than simple morphological observation.  
OBJECTIVE: To observe the staining effect of the intervertebral disc by Mallory trichrome staining from the changes of both tissue morphology and colors.
METHODS: L4-5 intervertebral disc of Hartley guinea pigs, which aged 1, 1.5, 2, 2.5 and 3 months, respectively. Discs were made into the central cornal plane tissue sections. Mallory staining and a light microscope was used to observe morphology and component and colors changes of nucleus pulposus, cartilage endplate and annulus fibrosus. SPOT-Ⅱ digital imaging system was utilized to capture images.
RESULTS AND CONCLUSION: Disc degeneration of Hartley guinea pigs aggravated naturally with age. Normal (1 month old) nucleus pulposus was colorless and transparent. At 1.5-3 months old, matrix of nucleus showed light blue color from local to all when degeneration, to indicate collagen eposition. Morphologically, notochord cells showed the degeneration of cartilage-like cells, the nucleus area was gradually narrowing and replaced by fibrous cartilage tissue. Nucleus was like to "serpentine" in modality at 3 months old. In the cartilage endplate, the purplish red cartilage cells belt showed irregular until disappear with age increasing. Morphologically, the cartilage cells were decreasing gradually, and the endplate was thinning, broken or disappeared. Red and orange area of outer annulus increased with age, to indicate fibrinoid degeneration. Lamellar structure could be seen clearly. The blue area of inner annulus was reduced gradually with age and the number of fibroblasts was decreased and disappeared. The results display that Mallory trichrome staining for Hartley guinea pigs intervertebral disc can show a good organizational resolutionin from both color and morphology, for matrix and cell which in the nucleus pulposus, cartilage endplate and the annulus, and visualizing the characteristic changes of intervertebral disc in the process of the natural increase of age from both morphology and component change.