Abstract:
1. The object in undertaking bile duct obstruction experiments in sheep, was to throw further light on the genesis of icterus and photosensitisation in true geeldikkop as caused by Tribulus spp. and also by other plants in South Africa.
2. The operative procedure as described for the ligation and obstruction of the extra-hepatic bile tracts in the sheep.
3. The ensuing clinical symptoms and the blood of operated animals were studied from day to day.
(a) A progressive bilirubinaemia was noted within one hour after operation. Clinical icterus, however, only presented itself several days afterwards and then persisted throughout the course of the condition. Within 24 hours the blood, and later also the urine, showed a strong direct van den Bergh reaction.
(b) Practically every animal, with the head and back closely shorn, when exposed to sunlight, developed symptoms of photosensitisation within one week of the operation. This was shown by the animals flinching, shaking the head and licking the lips. Soon afterwards oedema of the subcutis of the affected skin set in, e.g. the ears became thick and pendulous and the face swollen. Photosensitisation usually persisted for several days and in some cases lasted throughout the course of the condition. This was followed by hardening of the affected skin and sloughing of the superficial layers. Skin protected by a coat of wool remained normal.
(c) Animals with the biliary tract obstructed showed a progressive loss of condition up to the point of extreme emaciation.
4. On post-mortem the lesions found were those of intense generalised icterus, enlargement of the liver with marked bile stasis, dilatation of all the biliary tracts above the point of obstruction, enlargement and bile pigmentation of the kidneys, and frequently stasis in the large intestine.
5. Various modifications of the above operation were also attempted. The resultant symptoms and post-mortem lesions, however, were not altered or intensified to any extent.
