Collagen metabolism and phenotype after prostaglandin E2 treatment of granuloma: direct and macrophage-modulated effects

Type 3 procollagen peptide in bronchoalveolar lavage fluid. Poor indicator of course and prognosis in sarcoidosis

To investigate the role of bronchoalveolar lavage type 3 procollagen peptide as a prognostic indicator in sarcoidosis, we measured type 3 procollagen N-terminal peptide levels in lavage fluids from 84 sarcoidosis patients and monitored disease progress in these patients for a period of 12 months. Lavage procollagen peptide levels were significantly elevated in sarcoidosis patients compared to control subjects (p less than 0.001). No association was observed between lavage type 3 procollagen peptide and disease severity, as assessed by lung function tests. Follow-up monitoring of patients failed to demonstrate any relationship between subsequent functional deterioration and initial lavage type 3 procollagen peptide. These results suggest that elevated lavage type 3 procollagen peptide concentrations in sarcoidosis may reflect increased type 3 collagen synthesis associated with the inflammatory process rather than signal an early event in the development of chronic disease.

The influence of indomethacin on tendon healing. A biomechanical and biochemical study

The influence of indomethacin on the biomechanical and biochemical properties of tendons during their healing was investigated. In 68 New Zealand White rabbits a transverse tenotomy followed by repair with a criss-cross suture was performed in the plantaris longus tendon of the left hind limb. The leg was immobilized for 4 weeks postoperatively in a long-leg plastic splint. Half of the animals were treated with indomethacin, 10 mg/kg/day orally, and the other half with placebo. After 4, 8, and 16 weeks of treatment the animals were killed and biomechanical and biochemical parameters were measured. After 16 weeks there was a significant increase in tensile strength in the indomethacin group. There were only small biochemical differences between the groups. However, there was a slight but significant decrease in the amount of soluble collagen in the indomethacin group. This may indicate a higher degree of cross-linkage following indomethacin treatment, which might explain the increased tensile strength.

Effects of intratracheal administration of bleomycin on prostaglandins and thromboxane-B2 and collagen levels of the lung in hamsters

The effects of intratracheal administration of one unit of bleomycin on the lung levels of different prostaglandins (PGs), thromboxane B2 (TxB2), and total collagen were investigated in hamsters in two separate sets of this study. Averaging the values from two sets, the lung levels of 6-keto-PGF1 alpha (stable metabolite of PGI2), TxB2 (stable metabolite of TXA2), PFG2 alpha, and PGE in bleomycin-treated animals were increased by 11-, 7.5-, 7-, and 3-fold over the saline control at 14 days post treatment, respectively. The total lung collagen content in bleomycin-treated animals was significantly increased to 180% of the control during the same period. A number of possibilities for a marked variation in the levels of rise for different PGs and TxB2 and their significance in bleomycin-induced lung fibrosis have been discussed. It was concluded from the findings of the present study that there is a relationship between the lung levels of various metabolites of arachidonic acid cascade and bleomicin-induced increases in the synthesis and accumulation of lung collagen. The nature of this relationship, however, remains to be elucidated.

Prostaglandins in colonic anastomotic healing

In this study we report the effects of flurbiprofen and prostaglandin E2 on anastomotic tensile strength, collagen synthesis, and collagenolytic activity which are in a particularly fine balance in colonic healing. Colonic anastomoses were fashioned in 150 Sprague-Dawley rats which were allocated to receive either 20 mcg prostaglandin E2 in 1 ml saline, 1 ml saline alone (control) intraperitoneally for three days post-operatively, or oral 2.5 mg/kg flurbiprofen daily. Anastomotic bursting pressures, collagen content and collagenolytic activity were measured at three, six, and ten days. It was found that prostaglandin E2-treated animals had significantly weaker anastomoses at three days (102 +/- 6.1 mm Hg; m +/- SEM) compared with the control (126 +/- 7.3; P less than 0.02) or flurbiprofen group (128 +/- 4.6; P less than 0.01) with no differences at six and ten days. Collagen levels were higher in flurbiprofen-treated rats at three days (9.7 +/- 0.2 micrograms hydroxyproline/mg tissue) compared with the control (8.1 +/- 0.4 micrograms/mg; P 0.01) or prostaglandin E2 group (7.2 +/- 0.5 micrograms/mg; P 0.001). These differences were unchanged at six days but were not statistically different at ten days. Collagenolytic activity showed no differences in the three groups during the study. It is concluded that flurbiprofen enhances colonic healing with improved collagen synthesis without affecting collagenolytic activity.

Inflammatory pleuropulmonary fibrosis in essential fatty acid deficient rats and the lack of response to methysergide

In view of the association between essential fatty acid (EFA) deficiency and human cystic fibrosis, we have investigated the possible occurrence of pulmonary disease in rats fed an EFA deficient (EFAD) diet for 40 weeks. In contrast to a few slight spontaneous lesions consisting of pleural membrane hyperplasia, which were found in the lungs of control rats, a much greater incidence of fibrotic lesions was observed in the lungs of EFAD rats. These pleuropulmonary fibroses extended from the hyperplastic pleural membrane into the alveoli and were characterized by collagen deposition and marked macrophage infiltration to the extent that, in some cases, the alveolar septa were completely obstructed by inflammatory exudate. These findings lend indirect support to the contention that EFA deficiency plays a role in the aetiology of cystic fibrosis, at least with regard to pulmonary lesions. Administration of methysergide (10 mg/kg/day, p.o.) for a total of 11 weeks, did not alter the incidence of fibrosis in the lungs of EFAD rats, despite the finding that a man who had developed pleuropulmonary fibrosis as a result of chronic methysergide treatment exhibited a relative serum EFA deficiency. While a relative EFA deficiency may be a predisposing factor for the induction of fibrosis by chronic methysergide treatment, our data are not sufficient to make a decision upon this hypothesis.