Enzymatic diagnosis of steroid sulfatase deficiency by high performance liquid chromatography

Antipsychotic drugs inhibit the function of breast cancer resistance protein

The ABCG2 transporter breast cancer resistance protein (BCRP) has been identified in several physiological sites. It has been suggested to play an important role in disposition of many drugs and environmental toxins. We investigated the effects of several antipsychotic drugs, including risperidone, 9-hydroxy-risperidone (paliperidone), olanzapine, quetiapine, clozapine, haloperidol and chlorpromazine, and a positive control inhibitor Ko143 on functions of BCRP in MCF7 and BCRP over-expressing MCF7/MX100 cell lines using a BCRP prototypical substrate mitoxantrone. Our findings indicated that the tested antipsychotics rank order of potency of inhibition of BCRP according to concentrations required to reach 50% of maximum inhibition (IC(50)) was as follows: Ko143 (0.07 microM) > risperidone (38.1 microM) > clozapine (42.0 microM) > paliperidone (51 microM) > chlorpromazine (52.2 microM) > quetiapine (66.1 microM) > olanzapine = haloperidol (>100.0 microM). We further tested the effects of various concentrations of risperidone on the BCRP-mediated transport of oestrone-3-sulfate in a colon carcinoma cell line, Caco-2, a widely used model to study drug absorption. Our findings show that risperidone at concentrations ranging from 1 to 100 microM significantly inhibited intracellular accumulation of oestrone-3-sulfate in Caco-2 cell monolayers. The present results suggest that a potential source of pharmacokinetic interactions exists between BCRP substrates and several antipsychotics.

Frequency of steroid sulfatase deficiency in Hiroshima

A retrospective survey was performed between 1983 and 1995 to determine the frequency of steroid sulfatase (STS) deficiency in Hiroshima. Males with ichthyosis were diagnosed enzymatically. During 1979-95 in Hiroshima Prefecture, 275,943 males were born and 28 had STS deficiency. The observed frequency of STS deficiency was 1 per 9855 males. Therefore, STS deficiency is fairly prevalent in Japan.

Allergic disease as an association of steroid sulphatase deficiency

Ten of 31 patients with steroid sulphatase (STS) deficiency were found to have an allergic disease (bronchial asthma, allergic rhinitis, or atopic dermatitis). STS deficiency may predispose patients to allergic disease.

Improved high-performance liquid chromatographic method for N-acetylgalactosamine-4-sulfate sulfatase (arylsulfatase B) activity determination using uridine diphospho-N-acetylgalactosamine-4-sulfate

UDP-N-acetylgalactosamine-4-sulfate (UDP-GalNAc-4-S) was isolated from hen oviduct (isthmus) with a yield of 31 mumol per 100 g of wet tissue and used for arylsulfatase B (ASB) activity determination. Two HPLC methods of separation and quantitation of the reaction product were described: (1) an original gradient elution method which makes it possible to determine the reaction product when only partially purified ASB was used and additional uridine derivatives were formed during incubation; (2) an improved, fast isocratic elution method which may be used in the case of purified ASB preparations, devoid of other nucleotide hydrolysing enzymes. For both methods the detection limit was 0.1 nmol of product with standard error of determination < or = 3%. Using the gradient elution method we have found that UDP-GalNAc-4-S was hydrolysed by bovine arylsulfatase B1 most efficiently at pH 5.0 and concentration 0.5 mM with K(m) = 85 microM.

Mental retardation in a boy with an interstitial deletion at Xp22.3 involving STS, KAL1, and OA1: implication for the MRX locus

Although genotype-phenotype correlations in male patients with various types of nullisomy for Xp22.3 have assigned a locus for X-linked mental retardation (MRX) to an approximately 3-Mb region between DXS31 and STS, the precise location has not been determined. In this paper, we describe a 14 7/12 year old Japanese boy with mental retardation and an interstitial deletion at Xp22.3 involving STS, KAL1, and OA1, and compare the deletion map with that of previously reported three familial male patients with low-normal intelligence and a similar interstitial deletion at Xp22.3. The results suggest that the MRX gene is further localized to the roughly 1.5-Mb region between DXS1060 and DXS1139.