kaolinite and Anorexia

Donepezil, an acetylcholinesterase inhibitor, is associated with gastrointestinal symptoms, such as nausea, vomiting, and anorexia, which may affect adherence to continuous therapy. Since Rikkunshi-To, a Japanese herbal medicine, activates the ghrelin signaling pathway and promotes gastrointestinal function, it is administered to prevent gastrointestinal symptoms. We herein investigated whether donepezil-induced gastrointestinal side effects in mice are ameliorated by Rikkunshi-To and if its therapeutic efficacy is mediated by ghrelin. Since pica behavior, the ingestion of kaolin, correlates with nausea and vomiting in humans, donepezil was intraperitoneally administered with or without Rikkunshi-To daily to mice, and food and kaolin intakes were monitored. The effects of donepezil on intestinal motility and a ghrelin receptor antagonist on donepezil-induced pica behavior, anorexia, and changes in intestinal motility were examined in mice treated with Rikkunshi-To. Pica behavior and anorexia were significantly induced by donepezil and significantly inhibited by Rikkunshi-To. Intestinal motility was significantly suppressed by donepezil and promoted by Rikkunshi-To. Furthermore, the therapeutic effects of Rikkunshi-To were antagonized by the ghrelin receptor antagonist. The present results support the therapeutic efficacy of Rikkunshi-To against donepezil-induced gastrointestinal side effects.

Topics: Acetylcholinesterase; Animals; Anorexia; Donepezil; Drugs, Chinese Herbal; Ghrelin; Humans; Kaolin; Medicine, Kampo; Mice; Nausea; Pica; Receptors, Ghrelin; Vomiting

Intermittent subcutaneous injection of teriparatide, an active fragment of human parathyroid hormone, is clinically used for the treatment of osteoporosis. Patients suffer from nausea, which is one of the side effects teriparatide induces; however, the etiology of teriparatide-induced nausea remains unknown. We have reported pica, kaolin ingestion behavior, can be used as an assessment of nausea-related response in rats. In this study, we investigated the characteristics of teriparatide-induced pica and the abilities of anti-emetic drugs to inhibit teriparatide-induced pica. Male and female adolescent (4-week-old), young (8-week-old), and adult (30-week-old) naive rats, and ovariectomized (OVX: 17-week-old) and sham-operated (17-week-old) rats subcutaneously received teriparatide (0.4 mg/kg, n=4), and their kaolin and food intakes were monitored for 24 h after the injection. Among the tested rats, we found that OVX rats, rather than male, female, and sham-operated rats, showed marked teriparatide-induced pica (0 mg/kg: 0.17±0.07 g, 0.4 mg/kg: 6.18±0.91 g). Teriparatide-induced pica in OVX rats was inhibited by intraperitoneal pretreatment with serotonin 5-HT3 (granisetron 0.5 mg/kg), dopamine D2 (prochlorperazine 0.5 mg/kg), neurokinin NK1 (fosaprepitant 1 mg/kg), and histamine H1 (diphenhydramine 10 mg/kg) receptor antagonists to 70%, 11%, 19%, and 59% of that in vehicle-treated control, respectively. These results suggest that teriparatide-induced pica in OVX rats has the potential to reflect teriparatide-induced nausea; 5-HT3, D2, NK1, and H1 receptor activation is involved in the development of this behavior; antagonists of these receptors have the potential to be medical candidates used as treatments for teriparatide-induced nausea in human patients.

Topics: Age Factors; Animals; Anorexia; Antiemetics; Diphenhydramine; Disease Models, Animal; Dopamine D2 Receptor Antagonists; Dose-Response Relationship, Drug; Eating; Feeding Behavior; Female; Granisetron; Histamine H1 Antagonists; Kaolin; Male; Morpholines; Nausea; Neurokinin-1 Receptor Antagonists; Neurotransmitter Agents; Ovariectomy; Pica; Prochlorperazine; Rats, Wistar; Serotonin 5-HT3 Receptor Antagonists; Teriparatide

Anticancer agents, such as cisplatin, induce vomiting, nausea, and anorexia. Cisplatin primarily acts on vagal afferents to produce emesis, but little is known about how this drug generates nausea and anorexia. Electrophysiology indicates that cisplatin activates vagal afferents of the common hepatic branch (CHB). Rats lack an emetic response but do ingest kaolin clay (a pica response) when made sick by toxins, and this behavior can be inhibited by antiemetic drugs. It has been postulated that pica may serve as a proxy for emesis in the rat. The goal of this study was to assess the effect of CHB or ventral gastric (Gas) or celiac (Cel) branch vagotomies on pica and anorexia produced by cisplatin in the rat. The effects of apomorphine, a dopamine receptor agonist, which induces emesis via a central mechanism, were also assessed. Cisplatin-induced pica was suppressed by CHB vagotomy (a 61% reduction) but not by Gas and Cel vagotomy. Suppression of daily food intake and body weight following cisplatin treatment was also blunted by CHB ablation but not by Gas or Cel vagotomy. No vagotomy condition exhibited altered apomorphine-induced pica. The results indicate that the CHB, which innervates primarily the duodenum, plays an important role in cisplatin-induced malaise. These data suggest that pica has sensory pathways similar to emetic systems, since a vagotomy condition inhibited cisplatin-induced pica but had no effect on apomorphine-induced pica. This investigation contributes to the delineation of the physiology of pica and neural systems involved in malaise in the nonvomiting rat.

Topics: Animals; Anorexia; Antineoplastic Agents; Apomorphine; Body Weight; Celiac Plexus; Cisplatin; Dopamine Agonists; Drinking; Eating; Kaolin; Liver; Male; Pica; Rats; Rats, Sprague-Dawley; Stomach; Vagotomy; Vomiting

Cancer chemotherapy is frequently accompanied by severe emesis. The anti-cancer drugs are classified according to their clinical emetogenic potential. We have already found that kaolin ingestion behavior "pica" is analogous to emesis in rats. The aim of this study was to examine the effects of the clinical emetogenic potential of anti-cancer drugs on the induction of the pica in rats. Rats were housed in individual cages with free access to food and kaolin pellets and the daily food and kaolin intakes were measured for 3 days after the intraperitoneal administration of anti-cancer drugs (cisplatin, cyclophosphamide, actinomycin D, 5-fluorouracil and vincristine). The drugs with high potential for inducing emesis, such as cisplatin and cyclophosphamide, induced pica in all animals on the day of administration and the behavior lasted during the observation period. The drugs with moderate emetogenic potential, i.e. actinomycin D and 5-fluorouracil, also induced pica on the first and second day after the drug administration but the kaolin intake was less than that of the drugs with high potential. Vincristine, a drug with low emetogenic potential, slightly increased the kaolin intake in rats on the only first day of the administration. Cyclophosphamide, actinomycin D and vincristine induced anorexia and decreased their body weight during the observation period. These results suggested that the both amounts of kaolin intake and duration of behavior in the anti-cancer drug-induced pica are related to the clinical emetogenic potential of the drugs and the incidence of the anorexia is not related to their emetogenic potential.

Topics: Animals; Anorexia; Antineoplastic Agents; Cisplatin; Dactinomycin; Fluorouracil; Kaolin; Male; Pica; Rats; Rats, Wistar; Vincristine; Vomiting