1. The patch-clamp technique has been used to examine the action of the chemical phosphatase 2,3-butanedione monoxime (BDM) on ATP-sensitive K+ channels (KATP-channels) from mouse isolated pancreatic beta-cells in the absence of ATP and Mg2+. 2. BDM reversibly inhibited whole-cell KATP-currents with a concentration for half maximal inhibition (K(i)) of 15 +/- 1 mM and a Hill coefficient (n) of ...

Diacetylmonoxime Isonicotinoyl Hydrazone is new chromogenic reagent for the simultaneous determination of Gallium (III) and Aluminium(III). The reagent gives greenish yellow color in sodium acetateacetic acid buffer medium with the metal ions. The maximum absorbance at 377 and 367 nm for Ga(III) and Al(III) respectively. The molar absorptivities of Al(III) and Ga(III) are 2.69 x 10 and 3.17 x 1...

When activated skeletal muscle is stretched, force increases in two phases. This study tested the hypothesis that the increase in stretch force during the first phase is produced by pre-power stroke cross bridges. Myofibrils were activated in sarcomere lengths (SLs) between 2.2 and 2.5 microm, and stretched by approximately 5-15 per cent SL. When stretch was performed at 1 microms-1SL-1, the tr...

Intact rat ventricular trabeculae were injected with the salt form of fura 2, and the fura 2 ratio signal (R) was used to report intracellular Ca2+ concentration ([Ca2+]i). The fixed end relaxation phase of a twitch is associated with a slowing of the decay of the R signal, or even a reversal, to form a distinct bump, indicating a transient rise in [Ca2+]i. The bump is most prominent at 30°C, a...

THE ONLY METHOD available at present for the routine determination of citrulline in blood is the one first described by Archibald (1). This method is based on the original observation of Fearon (2) that in strongly acid solution citrulline condenses with diacetylmonoxime (DAM) to produce a peach-colored complex. Since urea also reacts with DAM under these conditions, Archibald removed it by inc...

Despite recent advances in our understanding of the mechanism for ventricular fibrillation (VF), important electrophysiological aspects of the development of VF still are poorly defined. It has been suggested that the onset of VF involves the disintegration of a single spiral wave into many self-perpetuating waves. It has been further suggested that such a process requires that the slope of the...

The role of contracture in the manifestation of calcium paradox-induced damage was examined using 2,3-butanedione monoxime (BDM) to inhibit myofibrillar activity. Calcium and sodium gain, loss of intracellular components, and changes in structure were monitored. If 30 mM BDM was added at the time of calcium repletion after 10 minutes of calcium-free perfusion, some protection was afforded, part...

A novel and efficient method for the synthesis of N,N-dialkylaminoisopropyl- and O-alkylisopropyl-2-(1-alkyl-2-oxopropylidene)phosphonohydrazido oximes (4) using activated silica as dehydrating agent has been developed. The reaction involves the condensation of substituted diacetyl monoxime and N,N-dialkylaminoisopropyl-phosphono hydrazide or O-alkylisopropylphosphono hydrazides and gave the co...

A simple and sensitive derivative spectrophotometric method has been developed for the determination of thallium(III) using a newly synthesized reagent diacetylmonoxime-(p-anisyl)-thiosemicarbazone in acetic acid medium. The molar absorptivity and Sandell’s sensitivity of the coloured species are 5.6×10 L mol cm and 3.6 ng cm, respectively. Beer’s law is obeyed between 0.25 and 2.60 μg mL of Tl...