Effects of D-penicillamine, dichlofenac sodium and gold sodium thiomalate upon the selective release of lysosomal enzymes from human polymorphonuclear leucocytes to immune complex

The effect of sodium aurothiomalate on stimulated and non-stimulated migration by human neutrophils: the role of cyclic GMP

Preincubation of human neutrophils with aurothiomalate had little effect on random migration or chemotactic migration towards the chemotactic peptide fMLP. However, a strong enhancement of migration was observed when aurothiomalate was present in a concentration gradient; the effect of the drug was chemotactic rather than chemokinetic. Thiomalate also caused a chemotactic enhancement of migration but here a tenfold higher concentration of the drug was required as compared with aurothiomalate. Aurothiomalate caused an increase of cellular cGMP level, and inhibitors of guanylate cyclase inhibited the activating effect of aurothiomalate. Three specific antagonists of cGMP-dependent kinase (G-kinase) strongly inhibited aurothiomalate-induced migration of electroporated neutrophils. The results suggest that stimulation of migration by aurothiomalate is mediated by cGMP and a G-kinase. Monoclonal anti-IL-8 inhibited aurothiomalate-induced stimulation of migration. Though no increased release of IL-8 could be established upon exposure of neutrophils to aurothiomalate, it seems conceivable that the stimulating effect of aurothiomalate is mediated by IL-8.

Blood monocyte elastolytic activity enhanced by immune complex stimulation in patients with rheumatoid arthritis and normal controls. Effect of aurothiomalate or D-penicillamine

Blood monocyte elastolytic activity in patients with rheumatoid arthritis and in normal controls was studied by a new in vitro technique. The enzyme activity of live cells was measured by soluble [3H]elastin hydrolysis first under basic conditions and then after immune complex stimulation. The cells from patients had a higher elastolytic potential than cells from controls (p less than 0.02) and responded to smaller amounts of immune complex (p less than 0.01), even in patients treated with D-penicillamine or aurothiomalate. Treatment of normal monocytes in vitro with aurothiomalate did not influence the elastolytic response. These findings indicate that monocytes from patients with rheumatoid arthritis have an enhanced elastolytic activity compared with cells from normal controls and may invoke greater tissue damage on immune complex stimulation.

Effect of two gold compounds on lysosomes

The effect of two gold(I) compounds on stability of lysosomes in vitro was studied. Lysosomes from homogenates of rat kidney cortex were isolated by differential centrifugation. These lysosomes were incubated at 37 degrees C with widely varied concentrations of sodium aurothiomalate and sodium aurothiosulphate for 5, 35, and 65 minutes. Acid phosphatase activities were measured and used as an indication of lysosomal membrane stability in the presence and absence of drugs. The enhanced release of acid phosphatase from lysosomes by aurothiomalate and aurothiosulphate was related to dose, but the drugs differed substantially in their potencies. The disruptive effect on lysosomes was more marked for aurothiosulphate than for aurothiomalate. In addition, both drugs inhibited acid phosphatase activities at relatively high gold concentrations. Aurothiomalate had a moderate and aurothiosulphate a weaker inhibitory effect on the enzyme. Our results indicate that aurothiomalate and aurothiosulphate exert their beneficial effect in the treatment of rheumatoid arthritis through mechanism(s) other than lysosomal membrane stabilisation.

Diclofenac sodium. A reappraisal of its pharmacodynamic and pharmacokinetic properties, and therapeutic efficacy

Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) advocated for use in painful and inflammatory rheumatic and certain non-rheumatic conditions. It is available in a number of administration forms which can be given orally, rectally or intramuscularly. Conveniently, dosage adjustments are not required in the elderly or in those patients with renal or hepatic impairment. The drug has a relatively short elimination half-life, which limits the potential for drug accumulation. In numerous clinical trials the efficacy of diclofenac is equivalent to that of the many newer and established NSAIDs with which it has been compared. As an analgesic it has a fast onset and long duration of action. When administered intramuscularly it is at least comparable to, and frequently superior to, many narcotic and spasmolytic combinations in renal and biliary colic. Extensive clinical experience has been gained with diclofenac, clearly establishing its safety profile. It is well tolerated compared with other NSAIDs and rarely produces gastrointestinal ulceration or other serious side effects. Thus, diclofenac can be considered as one of the few NSAIDs of 'first choice' in the treatment of acute and chronic painful and inflammatory conditions.

Effect of sodium thiomalate on immune complex-induced release of lysosomal enzymes from human polymorphonuclear leucocytes

The extracellular release of beta-glucuronidase and beta-N-acetylglucosaminidase from normal human polymorphonuclear leucocytes initiated with bovine serum albumin/anti-bovine serum albumin immune complex (15 micrograms/ml) was significantly inhibited (p less than 0.01) by pretreatment with increasing concentrations (10(-8) M, 10(-7) M, 10(-6) M and 10(-5) M) of sodium thiomalate in a time- and dose-related fashion. Also, beta-glucuronidase and beta-N-acetylglucosaminidase exhibited similar responses to the effects of bovine serum albumin/anti-bovine serum albumin or sodium thiomalate. In contrast, neither bovine serum albumin/anti-bovine serum albumin nor sodium thiomalate provoked appreciable leakage of the cytoplasmic enzyme, lactate dehydrogenase. This indicates that cell integrity remains intact under the experimental conditions described.