Search Results

Abstract.

In prostatic cytosol DHT¹ is metabolized to 5α-androstane-3α (or β), 17α-diols with a half life of 2 h even at 4°C. Thus, [³H]DHT appears to be a poor marker for a quantitative assessment of androgen receptors (AR). Methyltrienolone (R1881) seems to be advantageous as it is not metabolized. However, because of considerable binding to progestin receptors, assays using [³H]R1881 are not specific for AR in tissues containing progestin receptors. We, therefore, developed a specific assay for AR using [³H]DHT (14 nm) as marker, where metabolism of DHT is prevented by pre-incubation with NAD⁺-nucleosidase.

The [³H]DHT-receptor complex is separated from free, SHBG-bound and unspecifically bound [³H]DHT by agar gel electrophoresis. The binding sites of high affinity and low capacity are characterized by suppression with unlabelled R1881 (2 μm) in a parallel assay. Under these conditions DHT and R1881 appear to have the same kinetics of association and dissociation.

Weighted non-linear regression analysis of specific binding capacity at various ligand concentrations reveals that in rat prostatic cytosol the affinity of DHT (K_d = 0.405 ± 0.0839 nm) is significantly higher (P < 0.01) than that of R1881 (K_d = 1.25 ± 0.271 nm).

During recent years numerous reports on the favourable results of short-term trials with GH in patients with constitutional delay of growth and adolescence (CDGA) have been published, but it has been unclear whether such treatment affects final height. In the present study, the results of long-term therapy with GH in replacement doses have been evaluated in 15 patients who were treated with GH for several years (three years on average). At the start of treatment, 10 of the children were prepubertal and 5 were in puberty. All patients were followed up until final height was reached. Mean final height of the 13 male patients was 170.0±4.4 cm, i.e. −1.58 sds. In the two female patients, final height was 150.0 cm (−3.5 sds) and 164.0cm (−0.8 sds), respectively. Adult height of the patients lagged behind target height by 5.4±3.2 cm (mean±sd), Measured adult height corresponded to adult height as predicted prior to treatment. In conclusion, GH treatment of patients with CDGA did not increase final height.