Effect of prior sporidesmin intoxication on the pancreopathy associated with zinc oxide toxicity.

Aim: To demonstrate the effect of prior sporidesmin-induced liver injury on the pancreopathy of zinc-induced toxicity.

Methods: Four groups, each of 15 sheep, were given 2 x 2 treatments of sporidesmin (0.3 mg/kg bodyweight spread over 3 consecutive days prior to zinc) and zinc (200 mg Zn/kg bodyweight as ZnO spread over 24 days) starting 4 days after the end of sporidesmin dosing.

Urinary excretion of immunoreactive sporidesmin metabolites in sheep in relation to factors influencing susceptibility to sporidesmin intoxication.

Aim: To study the urinary disposition of orally administered sporidesmins A and D in sheep and identify factors influencing their kinetics, particularly the influence of breeding for resistance and susceptibility to sporidesmin, the mycotoxin responsible for the hepatogenous photosensitisation, facial eczema.

Methods: A competitive ELISA was used to monitor urinary output of immunoreactive metabolites after the intraruminal administration, to female Romney sheep, of either sporidesmin A or sporidesmin D, the nontoxic analogue. Preliminary characterisation of metabolites was carried out using HPLC with fractions monitored by ELISA.

Effect of the mycotoxins penitrem, paxilline and lolitrem B on the electromyographic activity of skeletal and gastrointestinal smooth muscle of sheep.

The electromyographic (EMG) activity of skeletal muscle was investigated as a method of recording the tremorgenic activity of the mycotoxins penitrem, paxilline and lolitrem B in sheep. EMG recordings were made concurrently from the abomasal antrum and duodenum to study the effects of these tremorgens on smooth muscle of the gut. Penitrem (2.

A simple gag for the intragastric dosing of guinea pigs (Cavia porcellus).

A simple gag has been designed and tested which enables the intragastric intubation of the guinea pig by one person without the use of sedation or light anaesthesia. The system described was used successfully for the daily dosing of materials to 7 guinea-pigs for 14 days without discomfort, aspiration or any injury to the upper gastro-intestinal tract.

Sequential changes in the development of the pancreatic lesion of zinc toxicosis in sheep.

Forty-two 10-month-old castrated male sheep were dosed with zinc oxide to study the pathogenesis of the pancreatic lesion. For 4 weeks, the sheep were dosed three times per week with 240 mg Zn (as ZnO)/kg body weight/dose, and seven groups of six sheep each were necropsied at 4, 7, 14, 21, 28, 56, and 112 days after the start of dosing. Plasma zinc concentrations rose rapidly to 2.