Cisplatin‐induced early and delayed emesis in the pigeon

Abstract

1 Intravenously injected cisplatin at a dose of 4 mg kg 71 induced early and delayed emesis in all pigeons without occurrence of lethality during a 72 h observation period. The early emetic response occurred with a latency of 81.3+8.0 min (n=15) and reached a peak at 2 ± 3 h, and decreased gradually within 8 h after injection. Then the delayed emetic response, whose peak was found between 10 to 23 h, lasted up to 48 h. The emetic response markedly declined after 48 h. 2 Reserpine markedly reduced monoamine levels in both brain and intestine and completely abolished the early and delayed emesis. Dexamethasone markedly reduced not only the early but also the delayed emetic responses. p-Chlorophenylalanine decreased the level of serotonin in brain and intestine without aecting noradrenaline and dopamine and partly reduced the early emetic response, but did not aect delayed emesis. 3 Bilateral vagotomy prolonged the latency time to the onset of early emesis, and reduced the emetic responses in both the early and delayed phases. 4 The above results suggest that the cisplatin-induced early emesis in the pigeon is partially mediated via the vagal nerve and reserpine-sensitive monoaminergic systems including the serotonergic system; the delayed emesis is associated with monoaminergic but not the serotonergic systems.

Dexamethasone Has a Central Antiemetic Mechanism in Decerebrated Cats

“…The antiemetic effect of dexamethasone has also been demonstrated in several animal models of emesis, such as in cats (4), dogs (5), ferrets (6), and pigeons (7). Our previous study showed that dexamethasone attenuated xylazine-induced emesis in cats (8).…”

Role of gastrointestinal motility/gastric emptying in cisplatin-induced vomiting in pigeon

“…On the day of experiment, the pigeons were transferred to individual cages specially designed for video observation and cisplatin (7 mg/kg) was administered intravenously via the brachial wing vein (Tanihata et al, 2000). The dose of cisplatin was selected on the basis of our previous studies in which it induced vomiting in all the animals tested (Unpublished data).…”

Nausea and emesis: still an unsolved problem in cancer patients?

“…Although stepwise improvements have been achieved in the past 20 years, a number of cancer patients still suffer from nausea and vomiting during the course of their disease. In this issue of Supportive Care in Cancer four papers focus on some of the platin-induced delayed emesis in pigeons [12], whereas para-chlorophenylalanine, a serotonin synthesis inhibitor, did not. This led the authors to suggest that dopamine and noradrenaline, but not serotonin, might be involved in the development of delayed emesis.…”