Effects of excess dietary cholesterol on adrenal cholesterol accumulation and steroidogenesis.

Rats maintained on diets containing 3% cholesterol for 10 weeks show marked increase in adrenal cholesterol content. The greatest part of the increase is in the cholesterol ester fraction (329%), although free cholesterol is also elevated (140%). Morphologically, a marked increase in the lipid droplet content of the cells is observed. The microsomal fraction was enriched in cholesterol with parallel increases in microsomal ACAT activity in both normal and supplemented groups. Neutral cytosolic cholesterol esterase is unaffected by the diet. No significant increase in cholesterol occurred in the mitochondrial fraction. However, cholesterol binding to cytochrome P450 was affected by the diet under certain conditions. Cholesterol supplementation elevates adrenal corticosteroid levels (43%). Mild stress results in greater increases in adrenal corticosteroids after dietary supplementation. Aminoglutethimide produces inhibition of the stress induced increase in adrenal corticosteroids. This inhibition is less pronounced in cholesterol supplemented animals than in normal animals. The lack of similar effects on plasma corticosteroid levels suggests that enhanced metabolism and clearance of the plasma corticosteroids may be taking place.

Relationships between circadian cycles of rat adrenal cholesterol ester metabolizing enzymes, cholesterol, ascorbic acid, and corticosteroid secretion.

The circadian changes in rat adrenal cholesterol ester (CE) metabolism have been studied and related to the circadian changes in adrenal ascorbic acid and corticosterone levels and plasma corticosterone levels. Significant declines in the ratio of CE/C, cholesterol esterase (CEase) and acyl CoA:cholesterol acyl transferase (ACAT) activities occur during the peak and declining phases of adrenal and plasma corticosteroids, suggesting that when there is a decreased need for steroid precursors the amount of stored CE is decreased, and that the enzymes involved in CE metabolism decline in activity. Adrenal ascorbic acid has a biphasic rhythm with peaks at 0900 and 2200 h. The rhythm of ascorbic acid appears to be inverse to that of ACAT activity, suggesting possible relationships between the two parameters.

Effects of dietary ascorbic acid and vitamin E deficiency on rat adrenal cholesterol ester metabolism and corticosteroidgoenesis.

The effect of dietary ascorbic acid (AA) and deficiency of vitamin E, alone and in combination, upon adrenal steroidogenesis in rats have been tested in vivo. High concentrations of AA blocked the normal stress-induced increase in plasma and adrenal corticosteroid concentration. Adrenal cholesterol ester hydrolase activity was also markedly inhibited by the high AA diet, while acylcoenzyme A:cholesterol acyltransferase was significantly increased. Vitamin E deficiency caused generally opposite effect, while simultaneous excess AA and vitamin E deficiency caused these parameters to return toward control values. Thus the role of AA in blocking adrenal steroidogenic response to stress is confirmed. It's mode of action may be at least partly through control of cholesterol availability for steroidogenesis.

Quantitation of gold lymphocyte binding during chrysotherapy.

Carbon rod atomic absorption analysis (CRA) was applied to the quantiation of gold lymphocyte content (GLC) during chrysotherapy. Sensitivity and accuracy of CRA compared favorably with 195Au isotopic scintillation counting, circumventing the limitations and hazards of the latter in clinical applications. Picogram gold quantification of limited sample volume, less than 10 ml blood, e.g., 10(4)-10(5) lymphocytes (5 microliters) containing 5-10 pg was achieved. GLC after IM administration increased significantly in 60% of patients; for the remainder, GLC was observed to be independent of plasma gold content or cumulative dosage. GLC during auranofin administration (6 mg/day p.o.) approached values for IM gold despite significantly lower plasma levels. Unique sensitivity of CRA enables analysis of GLC under therapeutic conditions that could elucidate whether gold alters functional determinants.

Effect of chrysotherapy on parameters of immune response.

Thirty-nine subjects with classical or definite rheumatoid arthritis received weekly intramuscular gold sodium thiomalate (GST) to sustain gold blood levels of more than 320 microgram/dl. Statistical analysis revealed significant declines from pre-treatment values for IgM, IgG, and IaA. Rheumatoid factor titer decreased in 29 of 39 subjects, 15 becoming seronegative. Circulating lymphocytes decreased by 27%. The maximal suppressive effect on IgM was not achieved until the 3rd and 4th years of GST administration. Auranofin (AF) 6 mg/day was administered to 15 patients for an average interval of 45 weeks. In vitro and in vivo suppression of lymphocyte mitogen response with AF was more rapid in onset and significantly greater than with GST. Suppression of dinitrochlorobenzene skin sensitization was observed in AF patients. The clinical response in GST treated subjects correlated with suppression of immunoglobulins, rheumatoid factor titer, and circulating lymphocytes. A significant decline in these variables was not achieved for a corresponding interval with AF treatment. It is suggested that chrysotherapy may be applied more widely to immunologically-mediated disorders and perhaps be used to affect selectively B versus T mediated dysfunction.

Chrysotherapy. Suppression of immunoglobulin synthesis.

Forty-four subjects with classic or definite rheumatoid arthritis who were on individualized chrysotherapy were observed for changes in serum protein electrophoresis, immunoglobulins, and circulating lymphocyte counts. By paired variate analysis, significant declines from pretreatment values were recorded for the following--electrophoretic protein fractions: gamma, alpha-1, alpha-2, (P less than 0.05); immunoglobulins: IgM--53% (P less than 0.001), IgG--37% (P less than 0.01), IgA--34% (P less than 0.001). Rheumatoid factor decreased in 29 of 39 subjects, 15 becoming seronegative (P less than 0.001); circulating lymphocytes decreased by 27% (P less than 0.001). The maximal suppressive effect on IgG and IgM was not achieved until the third and fourth years of therapy by sustained weekly administration of gold sodium thiomalate (one year cumulative dosage, mean 2106 mg, range 1065-2,885; greater than or equal to 4 year cumulative dosage, mean 8747 mg, range 5,385-15,160 mg). An immunosuppressive effect is suggested by these results.

Chrysotherapy: pharmacological and clinical correlates.

Relationships between gold administration and serum gold content were observed in 56 RA subjects receiving up to five years of weekly chrysotherapy. Wide fluctuations in serum gold responses to standard 50 mg IM injections were noted. Individual adjustments to dosage schedules were made as dictated by patient serum gold responses. Enhanced clinical and laboratory response was prolonged with higher sustained serum gold concentration greater than 300 mug per cent. Maintaining serum levels greater than 300 mug per cent is postulated to facilitate access of gold to "effector sites" within the deeper compartments by providing higher sustained gradients between superficial (blood) and deeper body compartments. The complexity of the system of effector sites responsive to gold and their divergent location within the body likely affects the accessibility of the agent for these sites; hence, affecting the correlation between gold levels and therapeutic response. The application of pharmacokinetic principles in chrysotherapy, nevertheless, provides the basis for optimizing accessibility of the agent and the therapeutic response. (J Rheumatol 2: 401-410, 1975).

Protein sulphydryl depression during adjuvant arthritis.

The changes in plasma protein sulphydryl level were measured during the course of adjuvant-induced arthritis in rats. Major depressions in the plasma sulphydryl level occurred at the onset of adjuvant disease, and the extent of the depression was related to the severity of the disease. Plasma sulphydryl levels remain unchanged when the systemic arthritis is suppressed by inclusion of a competing antigen in the adjuvant. Changes in sulphydryl content of the plasma were shown not to be due to weight loss or decrease in plasma protein level.