Correlation of MMP(1) and TIMP (1) expression with pituitary adenoma fibrosis

To explore the correlation of matrix metalloproteinase-1 (MMP(1)) and tissue inhibitor of metalloproteinase-1 (TIMP(1)) with pituitary adenoma fibrosis. Thirty-eight pituitary adenoma specimens were divided into fibrous group (6 patients) and non-fibrous group (32 patients). MMP(1) and TIMP(1) expression was detected by RT-PCR and immunohistochemistry. The collagen content was determined by Sirius scarlet staining. In fibrous and non-fibrous group: (1) the collagen content was 20.95 +/- 8.42% and 7.98 +/- 5.18% respectively, and there was a statistical significance (P < 0.01). (2) The expression of MMP(1)mRNA was 0.47 +/- 0.40 and 0.59 +/- 0.54 respectively and its protein expression was 0.12 +/- 0.09 and 0.13 +/- 0.09 respectively, and there was no statistical significance (P > 0.05). Their expression was not related to collagen content (P > 0.05). (3) The expression of TIMP(1)mRNA was 1.61 +/- 1.09 and 0.79 +/- 0.59 respectively and its protein expression was 0.58 +/- 0.11 and 0.32 +/- 0.18 respectively, and there was a statistical significance (P < 0.01). Their expression was related to collagen content (P < 0.01). The pathological features of pituitary adenoma fibrosis are excessive collagen deposition. High expression of TIMP(1) may be an important cause.