Long term treatment of Graves' disease with iopanoic acid (Telepaque)

To investigate the long term utility of the cholecystographic contrast agent iopanoic acid (Telepaque) for treatment of Graves' hyperthyroidism, we studied 40 patients treated with 500 mg, orally, daily for 1-12 months. We measured thyroid size; body weight; serum T3, T4, and free T4 concentrations; and antithyroglobulin and antimicrosomal antibody levels at monthly intervals. Based on the effects of the therapy, the patients were divided into 3 groups: 6 patients had excellent responses with return of serum thyroid hormone levels to normal (group A); 12 patients had fair responses, but 1 thyroid hormone test remained elevated (group B); and 22 patients had minimal benefit (group C) with only slight clinical improvement and transient reduction of serum T3 concentration. Mean serum T3 levels decreased significantly after 1 month of therapy in all 3 groups and became normal in groups A and B, but the reduction in group C was not sustained. Mean serum T4 and free T4 levels remained above normal during the course of therapy in groups B and C. Sixty-eight percent of patients in group C had large goiters compared with 33% of group A and 25% of group B, and those in group C tended to have more severe biochemical hyperthyroidism initially. There were no significant changes in antibody titers during therapy. These data indicate that iopanoic acid is not effective therapy for many hyperthyroid patients.

The adrenocortical function of alloxan-induced diabetic rats

The purpose of this study is to investigate the adrenocortical function of alloxan-induced diabetic rats. Male rats of Wistar strain, weighing 200-250 gm were used. The results indicated that the adrenocortical response to stress and exogenous corticotropin (ACTH1-24) is decreased during the early diabetic stages (up to 6 days). Evidence from in vivo and in vitro studies shows that the depression is caused by the toxicity of alloxan on the adrenal cortex cells and not by the sudden rise of blood glucose levels. Streptozotocin (another diabetogen) has the same effect as alloxan on adrenal cortex cells.

An improved dispersed adrenal cell assay for corticotropin in rat plasma

The present study was designed to improve the dispersed adrenal cell technique for determining adrenocorticotrophic hormone (ACTH) concentrations in small amounts of rat plasma. Priming with ACTH, incubation with methyl-isobutylxanthine, or dexamethasone pre-treatment were employed as modifications. Of these, only dexamethasone pre-treatment increased the sensitivity of the assay. The adrenal fragments obtained from 10-12 adult male rats pre-treated with dexamethasone (100 micrograms/kg B.W.) one hour before sacrifice, were digested with collagenase and deoxyribonuclease solution for 30 minutes. The dispersed cells were collected by centrifugation and resuspended in Krebs-Ringer bicarbonate buffer containing 0.2% glucose and 0.5% bovine serum albumin. Aliquots of cell suspension (3-4 X 10(4)/tube) were incubated with various doses of ACTH1-24 or the eluate of plasma samples at 37 degrees C for 2 hours in an atmosphere of 95% O2/5% CO2 in a Dubnoff shaker. The quantity of corticosterone produced was measured fluorimetrically. The assay is precise (lambda = 0.06), extremely sensitive (10 fg/tube), and convenient. One skilled technician can handle 15 to 20 plasma samples per day using 10 rats as the source of assay cells. ACTH can be measured in as little as 10-50 microliters of eluate.