A sublethal dose of sarin (GB, isopropyl methylphosphonofluoridate) was administered to mice. The animals were killed up to 28 d after dosing and frozen sections were made of the excised diaghragms which were stained using haematoxylin and eosin and a modified Gomori trichrome method. Muscle fibre degeneration and mononuclear infiltration were seen, notably at 24 h and 3 d. A number of histochemical procedures were carried out, including the GBHA procedure for ionized calcium. Calcium accumulation, seen at 4 h, was the earliest abnormality observed. All changes were rapidly regressing by 5 d and histological appearances were normal by 14 d. It was concluded that sarin produced myopathic changes preceded by calcium accumulation.

CDPA blood of human origin was 'spiked' with a solution of potassium cyanide at four different concentrations. When such blood was left in contact with the atmosphere for up to 10 min an appreciable amount of the cyanide was lost. Stoppered tubes containing the 'spiked' blood were stored at -20°C and 4°C for up to 6 months. Most samples, especially those 'spiked' at the highest concentrations, showed a loss of cyanide.

The LD50 of subcutaneously-injected sarin (GB: isopropyl methylphosphonofluoridate) in mice was 172 μg kg-1. Mice were treated with sarin at doses between 25 and 150 μg kg-1, administered subcutaneously. After sacrifice of the animals, the diaphragms were removed and stained for acetylcholinesterase activity and the presence of ionized calcium. Calcium was found in the diaphragms of those mice to which sarin had been administered at doses of 50 μg kg-1 or above. Calcium accumulation was not present in diaphragms from those animals that had received 25 μg kg-1. Calcium accumulation occurred earliest and remained longest in diaphragms from those animals receiving the highest doses. Accumulation of calcium was associated with end-plates, as demonstrated by an acetylcholinesterase histochemical method.