A sensitive radioimmunoassay, incorporating solid-phase extraction, for fluticasone 17-propionate in plasma.

Antibodies were produced in rabbits immunized with fluticasone 17-propionate (FP) conjugated to bovine thyroglobulin via its 3-carboxymethoxime with isobutylchloroformate. The antibodies were used to develop a sensitive and specific radioimmunoassay (RIA) for FP in human plasma. The limit of quantitation of the RIA is 50 pg per assay tube. This translates to 50 pg ml-1 plasma when a solid-phase extraction preceded the RIA. The interassay and intraassay relative standard deviations were < 15% in the centre of the assay concentration range rising to < 25% at the lower and upper limits (50 and 250 pg ml-1). No appreciable binding was seen between the antibodies and the metabolite of FP that has been identified in man. The RIA was used to study the time course of plasma concentrations in man following inhalation of FP.

Metalloprotein separation and analysis by directly coupled size exclusion high-performance liquid chromatography inductively coupled plasma mass spectroscopy.

The feasibility of using directly coupled size exclusion high-performance liquid chromatography inductively coupled plasma mass spectroscopy (HPLC/ICP-MS) for the separation and subsequent elemental analysis of metalloproteins in biological samples has been studied. Data, on up to eight elements, was acquired simultaneously and the reconstructed elemental profiles from the chromatographed samples were quantified by flow injection analysis. Absolute and relative detection limits, reproducibility, operational dynamic range, and linearity of response were initially evaluated by analyzing standards of metallothionein protein of known elemental composition for Cd, Zn, and Cu. There was evidence of displacement of Zn from the protein during chromatography and the substitution of Cu sequestered from the mobile phase. Cd associated with the protein was fully recovered during chromatography. Memory effects, due to protein adsorption to the glassware in the torch box, were minimal and there was no degradation of the resolution of the chromatographed peak during extended transport through the HPLC/ICP-MS interface. The versatility of the technique has been demonstrated by the quantitative multi-element analysis of cytosolic metal-binding proteins separated from the polychaete worm Neanthes arenaceodentata. Fidelity of analysis has been demonstrated by two independent procedures: first, by comparing the elemental profiles obtained by directly aspirating the HPLC eluant into the ICP-MS to those obtained by collecting fractions and quantifying the metal content of the proteins in the conventional analytical mode; second, by comparing the stable isotopic profiles for 114Cd obtained by simultaneous ICP-MS analysis with radiometric profiles of 109Cd obtained by counting radioactivity associated with collected fractions.(ABSTRACT TRUNCATED AT 250 WORDS)

The influence of phenelzine and tranylcypromine on the release of prostaglandins from the rat mesenteric vascular bed.

We investigated the effects of phenelzine and tranylcypromine on the release of prostacyclin, thromboxane A2, prostaglandin E2, and prostaglandin E1 from the isolated perfused rat mesenteric vascular bed. Perfusion of the preparation with phenelzine in concentrations of 15, 45, and 135 microM for 150 min led to attenuated release of all four prostaglandins measured. Inhibition generally occurred with the lowest dose used and was most prominent with the highest concentration. Tranylcypromine also decreased prostaglandin formation. However, low doses were not effective in the suppression of prostacyclin release. Both drugs had an inhibitory effect on production of prostaglandin E1, which is a metabolite of dihomo-gamma-linolenic acid, the precursor of arachidonic acid, but this was only shown to be significant with phenelzine. In this work we demonstrate that phenelzine and tranylcypromine have an inhibitory effect on the production of 2-series prostaglandins derived from arachidonic acid, and possibly a similar effect on prostaglandins of the 1-series derived from dihomo-gamma-linolenic acid.

Relationships between free cadmium ion activity in seawater, cadmium accumulation and subcellular distribution, and growth in polychaetes.

We have examined the relationships between Cd ion activity [Cd2+], in seawater, Cd accumulation and subcellular distribution and growth in the polychaete Neanthes arenaceodentata. Organisms were exposed for 3 weeks to a range of [Cd2+] in a Cd-chelate buffer system. Cadmium accumulation and growth were monitored weekly for each exposure group and subcellular Cd distributions were determined at the end of the 3-week period. We found Cd associated with all of the subcellular fractions except the very low molecular weight ligands. Total Cd accumulation was greatest at day 7 and decreased over time in all but the highest [Cd2+] where it remained constant. For each point in time, however, there was a linear relationship between total Cd and [Cd2+] in seawater. Linear relationships were also observed between [Cd2+] and Cd loading in each subcellular ligand pool. Specific growth rates varied with both [Cd2+] and time in a nonlinear manner.

Free cupric ion activity in seawater: effects on metallothionein and growth in crab larvae.

Crab zoeae (Rhithropanopeus harrisii) were exposed during their development opment to a range of free cupric ion activities regulated in seawater by use of a copper chelate buffer system. Most cytosolic copper was found to be associated with metallothionein. Copper-thionein could be related to free cupric ion activity, and a shift in copper-thionein accumulation was correlated with inhibition of larval growth. These data reveal predictable relations between cupric ion activity in seawater and processes at the cellular and organismic levels.