Steroid sulphatase activity in the skin biopsies of various types of ichthyosis

A simple method was developed for the determination of steroid sulphatase activity in a skin biopsy for routine use. In this method, 6 mg of minced tissue is incubated in 1 ml of Krebs-Ringer bicarbonate buffer with radioactive dehydroepiandrosterone sulphate (20,000 c.p.m., S.A. 1.1 Ci/mmol) for 4 h. After the incubation the liberated unconjugated dehydroepiandrosterone and its possible metabolites are separated from the conjugated compound by extraction with ethyl acetate-ethyl ether 10:90 (v/v). The organic phase is counted in a scintillation counter. The results are expressed as c.p.m. values per 6 mg tissue wet weight. Steroid sulphatase activity was measured in skin biopsies from nine control subjects and from thirteen patients with various types of ichthyosis. In the different groups studied, the ranges of the c.p.m. values were as follows: controls (n = 9) 377-1802; X-linked ichthyosis (n = 5) 140-214; ichthyosis vulgaris (n = 5) 607-1320; ichthyosiform erythroderma (n = 2) 2146-2214; lamellar ichthyosis (n = 1) 2185. The reagent blank varied from 180 to 259 c.p.m. In X-linked ichthyosis the c.p.m. values were always less than in the corresponding reagent blank, indicating that no enzyme activity was present in the tissue. In other types of ichthyosis, steroid sulphatase activity was normal. The method described is easy to accomplish in any clinical laboratory where scintillation counting is possible.

Postnatal development and sex differences in hepatic phosphatidate phosphohydrolase activity in the rat

The mechanism leading to the difference in hepatic triacylglycerol metabolism between female and male rats was investigated by studying the ontogeny of hepatic soluble phosphatidate phosphohydrolase activity in feeding animals of both sexes. A sevenfold increase occurred within 12 hr of birth, returning to the adult level during the third postnatal day. The changes in enzyme activity were followed by similar changes in hepatic triacylglycerol concentrations. A sex difference was observed only in the adult rats, where the enzyme activity in the livers of feeding female rats was about 25% higher than that in the feeding males. The effects of gonadectomy and sex steroids were studied in a separate series of experiments on fasting animals. The activity of the soluble enzyme was 65% higher in the intact female rats than in the males, and that of the microsomal enzyme 130% higher. The activity ratio between the soluble and microsomal enzyme in the male rats was 4.3 on a liver wet weight basis with the methods used. Gonadectomy increased the soluble and microsomal activities by 25% and 80% respectively within 6 wk in the male rats. The soluble and microsomal activities were still at the same control levels 2 wk after the gonadectomy, the subcutaneous implants of testosterone or estradiol resulting in 10-fold increases in plasma hormone levels had no effects on these enzyme activities, although testosterone caused 50% decrease in the hepatic triacylglycerol concentration. These data indicate that, if hormonally mediated, the postnatal increase in phosphatidate phosphohydrolase activities is not related to sex steroids and also suggest that the basis of the sex difference in hepatic soluble phosphatidate phosphohydrolase activity remains to be established.

A congenital ichthyosiform syndrome with deafness and elevated serum steroid disulphate levels

A congenital ichthyosiform syndrome with deafness and elevated serum steroid disulphate levels.

Serum steroid sulphates in ichthyosis

Serum concentrations of pregnenolone sulphate, dehydroepiandrosterone sulphate and 5-androstene-3 beta,17 beta-diol sulphate were measured by radioimmunoassays in twelve patients with various types of ichthyosis. In X-linked ichthyosis (n = 5), ichthyosis vulgaris (n = 5) and lamellar ichthyosis (n = 1), steroid sulphates were not significantly higher than in the control subjects. In one baby with ichthyosiform erythroderma and associated deafness serum 5 -androstene-3 beta,17 beta-diol sulphate concentration was about 60 fold higher (31 microgram/ml) than the mean of the control children. The other steroid sulphate levels were normal in this baby. These results indicate that it is not possible to demonstrate the steroid sulphatase deficiency in X-linked ichthyosis by determining blood steroid sulphates. The cause of the high 5-androstene-3 beta,17 beta-diol sulphate concentration in the baby with ichthyosiform erythroderma needs further evaluation.

The simultaneous radioimmunoassay of seven steroids in human spermatic and peripheral venous blood

Seven unconjugated neutral steroids, including testosterone and some of its precursors and metabolites, were measured in the peripheral and spermatic venous blood males, employing specific radioimmunoassays after the fractionation of steroids on Lipidex-5000 (hydroxyalkoxypropyl Sephadex) microcolumns. Respective mean concentrations (ng/ml) and ranges of steroids estimated in peripheral and spermatic venous blood in all groups of patients were as follows: pregnenolone, 0.71 (0.29-2.39) and 10.97 (0.83-30.1); progesterone, 0.31 (0.02-0.57) and 10.17 (1.51-33.24); 17 alpha-hydroxyprogesterone, 1.04 (0.48-2.20) and 37.33 (1.68-141.00); androstenedione, 1.01 (0.26-2.65) and 11.87 (0.97-30.18); testosterone, 3.84 (0.63-10.64) and 255.1 (2.85-619.1); 5alpha-dihydrotestosterone, 0.19 (0.07-0.28) and 3.74 (0.04-9.71); androsterone, 0.27 (0.12-0.47) and 0.97 (0.20-2.15). Concentrations are similar to those estimated by mass spectrometry and protein binding assays, except for androsterone which has not previously been measured in this context. The low, but significant testicular secretion of both 5alpha-hydrotestosterone and androsterone suggests that these two steroids are testicular androgen metabolites, and that androgen metabolism in this tissue may be monitored by way of their measurement in spermatic vein blood.