An experimental study on the effect of safflower yellow on tendon injury-repair in chickens.

BACKGROUND: The present study sought to investigate pathologic changes in tendon, expression of basic fibroblast growth factor (bFGF) and collagen type I, and effects of safflower yellow (SY) on the process of tendon injury-repair. MATERIALS AND METHODS: A tendon injury-repair model was used, and stereology, biomechanics, and immunohistochemistry were employed to assess the benefits of local application of SY for the repair. In this model, the flexor digitorum profundus muscle tendon of the third digit was transected bilaterally, and the transected ends sutured. Data were analyzed with SPSS ver. 10.0 software (SPSS Inc., Chicago, IL). RESULTS: The adhesion to surrounding tissues and tensile strength gradually increased after the injury and repair in control (no-SY) tendons, and were significantly greater by the sixth wk than any other time. In the SY tendons, adhesion was significantly lower, and tensile strength significantly higher than in no-SY tendons at the same post-injury-suture time points. An inflammatory reaction was observed in the injury-repair areas of the tendon by the end of first wk post-injury-suture, and reached its peak by the end of second wk. The inflammatory reaction was significantly less in SY tendons than in controls. Immunostaining for bFGF occurred in the tendon injury-repair areas by the end of first wk, and the number of bFGF positive cells reached a peak by the end of second wk, with a greater abundance in SY than control tendons from the second to sixth wk. Expression of collagen type I protein was observed in the injury-repair areas as well, coincident with bFGF, and was remarkably higher in SY than in controls. CONCLUSIONS: Tendon adhesion and tensile strength increased with time post-injury-suture repair, as did expression of bFGF and collagen type I protein in the injured area. SY enhanced expression of bFGF and collagen type I protein, enhanced the tensile strength of the injured tendon, and alleviated the injured tendon adhesion and inflammatory reaction. The results indicated that SY promoted the repair of injured tendon by up-regulating expression of bFGF and collagen type I protein.

The morphological characteristics of corticostriatal and thalamostriatal neurons and their intrastriatal terminals in rats.

PURPOSE: The glutamatergic projection from the cerebral cortex and the thalamus extensively innervates the neostriatal neurons. However, some conflicts in the published literatures about cortical and thalamic intrastriatal synaptic terminals still need to be resolved. The present study intends to further elucidate the morphological characteristics of these two types of the terminals and their neurons. METHODS: The corticostriatal and thalamostriatal terminals were immunolabeled for vesicular glutamate transporter type 1 (VGluT1) and 2 (VGluT2), respectively, and their neurons were retrograde labeled by biotinylated dextran amine 3,000 molecular weight (BDA3k) injection into the dorsolateral striatum of rats. The characteristics of the corticostriatal and thalamostriatal terminals were observed at the LM and EM levels, and the data were statistically analyzed with SPSS10.0 software. RESULTS: We observed that 63.53% of VGluT1+ terminals synapsed on dendritic spines, which was different from VGluT2+ terminals with the equal percentage of synapses on spines and dendrites (14.88 and 17.86%, respectively). Notably, VGluT1+ axospinous synaptic terminals were remarkably larger than VGluT2+ axospinous synaptic terminals. Terminal size-frequency distribution analysis showed that VGluT1+ terminals were within the size ranges of 0.4-0.5 and 0.8-0.9 µm, and VGluT2+ terminals were in the ranges of 0.4-0.5 and 0.6-0.7 µm. Perforated-postsynaptic densities (-PSDs) were more frequently found in VGluT1+ axospinous synaptic terminals than in VGluT2+ axospinous terminals. Furthermore, BDA3k-labeled corticostrital neurons were larger in perikaryal diameter than the thalamostriatal neurons, and they were also categorized as the two main populations based on their size-frequency distribution. CONCLUSIONS: The morphological characteristics of corticostriatal and thalamostriatal terminals and neurons have implications for understanding the roles of synaptic plasticity in adaptive motor control by the basal ganglia, and they have facilitations for understanding the complexities of basal ganglia function.