Effect of D-penicillamine on collagen biosynthesis in organ culture

Cystic kidney disease in a patient with systemic toxicity from long-term D-penicillamine use

D-penicillamine, used to treat cystinuria, is known to cause impaired collagen deposition and dysfunction in elastic fibers. D-penicillamine also has been associated with glomerular abnormalities, typically membranous glomerulonephritis. We describe a patient with severe bilateral cystic kidney disease that developed after long-term D-penicillamine use for treatment of cystinuria. The cysts in the kidneys were noted during an evaluation for acute kidney injury. The patient had no evidence of cysts on prior renal imaging at a time when his kidney function was normal. Simultaneously, he presented with multiorgan manifestations of D-penicillamine toxicity, including the skin findings of cutix laxa and elastosis perforans serpiginosa. Consequently, D-penicillamine treatment was discontinued, after which the progression of cystic kidney disease gradually ceased, along with the other systemic manifestations of toxicity. To our knowledge, this is the first report of cystic kidney disease associated with and perhaps caused by long-term d-penicillamine therapy. The proposed mechanism of cyst formation is the malfunction of the extracellular matrix of the kidney by d-penicillamine that leads to an impaired repair process after kidney injury.

The effect of D-penicillamine on CCl4-induced experimental liver cirrhosis

The effect of D-penicillamine (Pe) on liver fibrosis-cirrhosis induced by chronic CCl4 and phenobarbital (Pb) administration in Fischer 344 male rats was studied. Morphometric analysis did not reveal a decrease in the amount of connective tissue fibers after Pe-treatment. Compared to the CCl4 and Pb-treated control groups, Pe had no significant effect on the concentrations of hydroxyproline, a parameter of collagen degradation, either; however, it increased the glycosaminoglycan concentrations. Lymphocyte stimulation by Con-A in the Pe-treated groups did not differ from that of the CCl4 and Pb-treated ones. According to our studies, Pe-treatment was ineffective in rats with liver fibrosis-cirrhosis induced by CCl4 and Pb administration. It seems that Pe can be effective only in the cirrhosis types accompanied by a considerable copper accumulation due to suppression of the toxic effects of copper.

Proteoglycan biosynthesis is stimulated by D-penicillamine in chondrifying high density cell cultures

Chondrifying high density cell cultures of stage 22-24 chick embryo limb bud mesenchyme were treated with 5, 10 and 15 mmol/l D-penicillamine (DPA) for 4 and 6 days. The cultures were analyzed with morphological and biochemical techniques to learn more about the effect of DPA on the metabolism of cartilage glycosaminoglycans (GAGs). Using light and electron microscopic histochemical reactions for GAG, a considerable increase in the intensity of staining of the cartilage matrix could be detected in cultures treated with DPA as compared to the untreated controls. The uronic acid content of the treated cultures was higher than that of the controls. Liquid scintillation measurements and autoradiography revealed that DPA treatment increased the 35S-sulfate into the cultures. These data suggest that DPA - besides its well known inhibitory effect on collagen crosslink formation - alters the metabolism of sulfated GAGs in differentiating cartilage. It is supposed that DPA stimulates the biosynthesis of these macromolecules.

D-penicillamine-induced cleft palate in mice

The teratogenic potential of the lathyrogen, D-penicillamine (DP), was assessed in pregnant mice, especially with respect to its ability to produce cleft palate. The dosage and the duration of treatment as they relate to the induction of cleft palate were also studied. Two different doses of DP were administered orally for either 5 or 4 consecutive days during the critical period of palatal closure. D-penicillamine (DP) at a dose level which does not have any apparent maternal toxic effects produced cleft palate in the offspring, and this teratogenic effect depended more upon the duration of treatment than the dosage administered. Inhibitory effects on the formation of bone matrix were observed at the base of the palatal shelf. It is suggested that DP is potentially an osteolathyrogenic agent. The mechanism of induction of cleft palate in DP-treated mice was explored by histological studies using light microscopy. Delayed elevation of the palatal shelves was observed and is considered to be the cause of the induction of cleft palate. No other external malformations could be detected in DP-treated fetuses.

Effect of D-penicillamine pre- and post-implantation treatment on formation of sponge-induced granulation tissue in rats

DNA, collagen and sulfated glycosaminoglycans (GAGs) of rat sponge granulation tissue were studied after 42 days of D-penicillamine (D-pen) treatment at 100, 250 or 500 mg/kg/day, starting 10 days before or 28 days after induction of granulation tissue formation. The effects were compared with those observed when the same dosage was started at the onset of the granulation tissue formation and with pair-fed controls. D-pen stimulated the cell invasion into the sponge implants, as manifested by an increased DNA content, particularly with pre-treatment. Pre-treatment reduced the net deposition of of collagen per cell as assessed by the lower hydroxyproline/DNA ratio, at the lower dose leading to reduced collagen concentration. The total amount of granulation tissue collagen remained essentially unaffected within the observation period. Salt-soluble collagen was augmented in a dose-dependent manner, irrespective of treatment protocol, signifying decreased collagen cross-linking. Both pre- and post-implantation treatment enhanced the radiosulfate incorporation into sulfated GAGs, regardless of dose, whereas treatment from the day of sponge implantation had no effect. It is concluded that D-pen enhances the early connective tissue response to injury. Reduction of collagen cross-linking and net collagen deposition, concomitant with stimulation of the proteoglycan metabolism, may pertain to the antirheumatoid activity of D-pen. The observations suggest that long-term administration of D-pen, starting before new attacks of arthritis, may be most effective in controlling developing articular fibrosis.

Alcoholic liver disease

Aggressive management to prevent alcoholic cirrhosis should include the use of biopsy results to diagnose and to monitor alcoholic liver disease. Guidelines for the interpretation of the liver biopsy are highlighted. The diagnosis, course, and treatment of alcoholic hepatitis and cirrhosis are presented in detail.

The effect of D-penicillamine and methylprednisolone on the morphology of experimental granulation tissue in rats

The effects of D-penicillamine and methylprednisolone on the formation of granulation tissue was studied in rats with Visella-sponge induced granulation tissue after 42 days of treatment. D-penicillamine in doses of 20 mg-, 100 mg-, 500 mg/kg/day caused no morphological differences compared with the control groups as regards ingrowth of granulation tissue and its content of collagen fibres, inflammatory cells, vessels and glycosaminoglycans. Treatment with methylprednisolone, 0.2 mg-, 2.0 mg-, and 5.0 mg/kg/day caused a dose dependent reduction in the ingrowth of granulation tissue. Methylprednisolone caused a reduction in the number of fibroblasts and collagen fibres, but no differences in the content of glycosaminoglycans could be demonstrated between the treated and the control groups. Granulation tissue produced during combination treatment with D-penicillamine 100 mg and methylprednisolone 2.0 mg/kg/day did not differ from that observed after methylprednisolone treatment alone. Thus, only high doses of methylprednisolone gave rise to an antiinflammatory action in this morphological study on granulation tissue, whereas D-penicillamine had no effect within the present dose interval. The quantitative alterations are in agreement with parallel biochemical analyses. However, the inhibitory effect of D-penicillamine on collagen crosslinking was not associated with light microscopic changes in the ultrastructure of the collagen fibres.

Skin collagen biosynthesis in patients with rheumatoid arthritis treated with D-penicillamine

Collagen biosynthesis was measured in skin biopsies taken from 13 patients with rheumatoid arthritis before and after at least 6 months' continuous treatment with D-penicillamine, 1.0 g/day. There was a significant 36% reduction in mean collagen biosynthesis (p less than 0.0125) as assayed by 14C-hydroxyproline formation from 14C-proline during 24 h of tissue culture. The changes in 14C-hydroxyproline formation were correlated with the total doses of D-penicillamine taken (r = 0.71, p less than 0.01) and the falls in ESR (r = 0.72, p less than 0.01). No significant change in general protein syntehsis was observed. 500 microgram/mlD-penicillamine added to skil cultures in vitro inhibited both collagen and general protein synthesis (p less than 0.01). It is suggested that the clinical improvement induced by D-penicillamine could reflect an inhibition of collagen proliferation in the synovium.

[Proliferation of L 929 mouse fibroblasts and synthesis of active peptidyl prolyl hydroxylase in these cells in monolayer culture under the influence of D-penicillamine, azathioprine, aurothiopolypeptide, oxyphenbutazone and prednisolone (author's transl)]

L 929 mouse fibroblasts were cultured as monolayer using MEM Eagle medium after addition of bovine serum albumin, antibiotics, antimycotica, ferrous nitrate and ascorbic acid. In 24 hours distances cell number was counted. At the same time peptidyl prolyl hydroxylase activity was determined and related to the protein concentration in the cells. The proliferation of the cells followed a typical curve. The cell number decreased after trypsination, then increased logarithmically, finally reached a stationary phase. Enzyme activity showed a correspondent curve. Active enzyme did not appear until near the end of the log phase. After addition of the mesenchyme active substances in therapeutical concentrations proliferation and synthesis of active peptidyl prolyl hydroxylase in the cells were significantly decreased. The results are discussed in relation to the characteristics of collagen synthesis and proliferation of connective tissue cells under physiological, pathophysiological and therapeutical conditions.

The behavior of (14C)-D-penicillamine in collagen metabolism

The most important effect of penicillamine on collagen metabolism is the reduction of collagen crosslinking. However, even after long time application of penicillamine, collagen is crosslinked to a certain degree. After intravenous injection of a trace dose of (14C) labelled D-penicillamine it can be determined that this substance is rapidly bound to neutral salt soluble, acetic acid soluble and urea soluble collagen fractions and to a lesser extent to insoluble collagen as well. The amount of penicillamine which binds to any of the collagen fractions depends on the turnover rate. When different tissues are compared, penicillamine seems to have the greatest affinity to tissues with a high collagen turnover. Further studies of neutral salt soluble collagen by CM-cellulose chromatography revealed a stable linkage of penicillamine to collagen alpha chains.

Collagen and mechanical strength in various organs of rats treated with D-penicillamine or amino-acetonitrile

After oral treatment with D-penicillamine (D-Pc) or with aminoacetonitrile (AAn) for 10 days, mechanical and chemical parameters were studied simultaneously in various organs of Sprague Dawley rats. Tensile strength of skin strips and of tail tendons, breaking strength of femur bones and tensile strength of granuloma tissue (induced by implanted glass rods) were measured and calculated. In the same tissue the soluble collagen fractions and the insoluble collagen were determined. Total collagen and the ratio insoluble vs. soluble collagen were calculated. Tensile strength of skin, tendon and granuloma tissue were greatly reduced by D-Pc treatment but only minimally influenced by AAN treatment. On the other hand only AAN significantly reduced the breaking strength of bone. All these changes were closely correlated with the content of insoluble collagen in the respective tissues. The correlation coefficients to total collagen were similar but lower. The correlation coefficients between strength and the ratio insoluble vs. soluble collagen were generally still lower. Earlier findings in aged and corticoid treated rats, proving that insoluble collagen content determines mechanical strength of connnective and supporting tissue thus could be confirmed.