[Relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus: The SONIC study].

AIM: The purpose of this study was to examine the relationship between glycemic control and mental health in community-dwelling older people with diabetes mellitus (DM) from insights that contribute to the management of diabetes in consideration of quality of life (QOL). METHODS: We used the data of the Septuagenarians, Octogenarians and Nonagenarians Investigation with Centenarians (SONIC) study, a prospective cohort study of community-dwelling older people. The present study included 2,051 older subjects of 70±1 years, 80±1 years and 90±1 years of age. We conducted medical interviews, blood sampling, and the subjects were asked to complete a questionnaire (WHO-5-J) at the venue. Three hundred sixty-eight people were diagnosed with DM. The subjects of this study were 192 people who were undergoing drug therapy for glycemic control. A multiple regression analysis was performed to clarify the relationship between glycemic control (divided as follows: HbA1c<7.0%, good control group; HbA1c≥7.0%, poor control group) and the WHO-5-J score, as the dependent variable, after adjusting for any confounding factors. RESULTS: In subjects of 70 years of age, a negative association was found between glycemic control and the WHO-5-J score, with the good control group showing a significantly lower score (ß: -0.468, p<0.01) in comparison to the poor control group. In detail, we observed a significant difference in the sub-items of WHO-5-J, question item 3, "I have felt active and vigorous" at 70 years of age (good control group, 2.56±1.37; poor control group, 3.21±1.18; p=0.021) and question item 5, "My daily life has been filled with things that interest me" (good control group, 2.44±1.21; poor control group, 3.11±1.11; p=0.009). As for the two questions, the WHO-5-J scores were lower in the good control group. These associations showed no statistical significance at 80 years of age or 90 years of age. CONCLUSION: The results obtained in this study indicated that strict glycemic control management of diabetes mellitus may lead to a lower mental QOL in younger elderly individuals (70 years of age). Therefore, it is important to pay attention to the mental burdens of the management of glycemic control in older people with DM.

Effects of Rikkunshi-To, a Japanese kampo medicine, on donepezil-induced gastrointestinal side effects in mice.

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.

Utilizing Graphical Analysis of Chest Radiographs for Primary Screening of Osteoporosis.

Background and Objectives: Osteoporosis is a major risk of fractures, harming patients' quality of life. Dual-energy X-ray absorptiometry (DXA), which can detect osteoporosis early, is too expensive to be conducted on a regular basis. Therefore, we aimed to evaluate a screening method using chest radiographs developed in Japan applied to another population. Materials and Methods: Fifty-five patients who had a chest radiograph and DXA and applied within three months of each test were recruited from the patient database of Semmelweis University (Budapest, Hungary). Graphical analysis of the chest radiographs was conducted to identify the ratio of the cortical bone in the clavicle of each patient. Two researchers performed the analysis, and multiple regression was conducted to determine the bone mineral density of each patient provided by DXA. Results: The Pearson correlation between two examiners' determinations of the cortical bone ratio was 0.769 (p < 0.001). The multiple regression model proved to be statistically significant in identifying osteoporosis, but the model adopted for the Hungarian population was different compared to the Japanese population. Conclusions: This simple, economic Japanese graphical analysis method for chest radiographs may be feasible in detecting osteoporosis. Further studies with a larger population of patients with greater variety of ethnicity would be of value in improving the accuracy of this model.

Involvement of leukotriene pathway in the development of sevoflurane-induced pica in rats.

We previously reported that sevoflurane-induced pica, kaolin ingestion behavior, in rats has the potential to reflect postoperative nausea and vomiting (PONV) in humans. It is well-known that corticosteroids, which inhibit both prostaglandin and leukotriene syntheses due to phospholipase A2 inhibition, are effective for reducing PONV; however, the precise mechanisms remain unclear. We investigated the involvement of the prostaglandin or leukotriene pathway in the development of sevoflurane-induced pica. We found that sevoflurane-induced pica was effectively inhibited by pretreatment with a leukotriene receptor antagonist (montelukast) or an inhibitor of 5-lipoxygenase (zileuton), rather than an inhibitor of cyclooxygenase (flurbiprofen). Furthermore, we observed that sevoflurane significantly increased urinary leukotriene excretion and 5-lipoxygenase mRNA expression in the spleen, but not hypothalamus. These results suggest that the production of leukotriene may lead to the development of sevoflurane-induced pica in rats, and that inhibition of the leukotriene pathway could be potentially useful for the treatment of PONV.

[A Case Report of Breast Cancer Followed Up as Intraductal Papilloma].

The patient was a 50-year-old woman. She had been diagnosed with bilateral breast tumors at another hospital 5 years previously and was followed up every 2 months. Ultrasonography showed hypoechoic masses in her breasts. The largest tumor in the right breast was 15mm in diameter and located in region A, while that in the left breast was 8mm in diameter and located in region B. Magnetic resonance imaging(MRI)showed multiple bilateral breast tumors. The largest tumor was 12mm in diameter and was suggestive of breast cancer. Core needle biopsies(CNB)of the largest tumors in both breasts were performed. Intraductal papilloma(IDP)and low-grade intraductal papillary carcinoma were diagnosed in the right and left breasts, respectively, on immunohistochemical staining. We performed left nipple-sparing mastectomy with sentinel lymph node biopsy and right tumor excision for diagnoses of carcinoma of the left breast(cTisN0M0)and IDP of the right breast. The histopathological diagnosis of the left breast tumor was pT1aN0M0, triple negative breast cancer with extensive intraductal components, and that of the right breast tumor was IDP with atypical ductal hyperplasia. Chemotherapy was administered postoperatively. Several studies have reported that peripheral IDP often coexists with or follows the development of carcinoma. Therefore, we should also closely follow-upthe patient's right breast.

[A Patient with Breast Cancer Who Achieved Continued Clinical Complete Response after Systemic Therapy Alone].

A 53-year-old woman presented at our hospital because of a mass in the left breast. A mass measuring 2 cm in diameter was palpated in the upper outer region(C region)of the left breast. Mammography showed a mass with calcification. Mammary ultrasonography showed a mass measuring 18×16×14mm and enlarged lymph nodes in the left axillary region. Core needle biopsy revealed Luminal B invasive ductal carcinoma(scirrhous type). The estrogen receptor(ER)positivity was 95%, progesterone receptor(PgR)positivity was 60%, human epidermal growth factor receptor type 2(HER2)score was 2+, fluorescence in situ hybridization(FISH)showed no amplification, and Ki-67 index was 60%. Clinical T1N1M0, StageⅡA cancer was thus diagnosed. As preoperative chemotherapy, the patient received 4 courses of treatment containing epirubicin (100mg/m2), 5-fluorouracil(500mg/m2), and cyclophosphamide(500mg/m2; FEC100), and 4 courses of treatment containing docetaxel and cyclophosphamide(TC). Clinical complete response(cCR)was confirmed on imaging studies. The patient was explained about the need for surgery, but she refused to undergo surgery. The patient is being followed up while receiving endocrine therapy, and there has been no recurrence or metastasis as of 2 years. We described our encounter with a patient with breast cancer who refused surgery after preoperative chemotherapy and has had no recurrence or metastasis during follow-up.

Enhancement of ghrelin-signaling system by Rikkunshi-To attenuates teriparatide-induced pica in rats.

Teriparatide is clinically used for the treatment of osteoporosis; however, nausea is often observed in patients. Its insufficient control affects the ability to continue teriparatide therapy. Rikkunshi-To (RKT), a traditional Japanese herbal medicine, improves the gastrointestinal function via activation of the ghrelin-signaling system. We investigated the therapeutic effects of RKT on teriparatide-induced nausea in rats and the involvement of ghrelin in these effects. We previously reported that ovariectomized rats showed pica (kaolin ingestion), a behavior that can be used to assess nausea in rats, after the subcutaneous administration of teriparatide; thus, the behavior was used as an index of nausea. Ovariectomized rats were fed diets with or without RKT (1%) for 2 weeks, and then they received the subcutaneous injection of teriparatide (400 µg/kg). Teriparatide significantly increased the incidence of pica, while suppressing intestinal motility and plasma ghrelin levels in rats fed normal diets; however, rats fed diets with RKT showed improvements in all of the teriparatide-induced adverse reactions. These therapeutic effects were antagonized by a ghrelin receptor antagonist ([D-Lys3]-GHRP-6; 200 nmol/rat). These findings suggest that the enhancement of ghrelin-signaling is involved in RKT's therapeutic effect, and that RKT is a potentially useful treatment for teriparatide-induced nausea.

[A Case Report of Ipsilateral Nipple Skin Recurrence].

We report our experience with a patient with breast cancer who showed recurrence in the nipple skin 5 years and 10 months after a breast-preserving surgery. The patient was a woman, and was 65-years old at the time of initial surgery. Breast-preserving surgery and axillary lymph-node dissection were performed for left breast cancer. Invasive ductal carcinoma of the breast(pT3N0M0)was triple-negative, and the patient postoperatively received adjuvant chemotherapy. Left breast pain developed 5 years and 6 months after surgery. Computed tomography showed no evidence of recurrence, and the symptoms resolved after treatment with non-steroidal anti-inflammatory drugs(NSAIDs). After 3 months, however, the left nipple had enlarged to about 1.5 cm, and the surrounding skin was red and painful. Treatment with NSAIDs was thus resumed. After 1 week, redness of the nipple skin and pain were improved. However, the nipple had enlarged to twice its normal size. Nipple skin biopsy was subsequently performed, and revealed adenocarcinoma invading the skin. Left axillary lymph-node metastasis was suspected, but there was no evidence of metastasis to other sites or recurrence. Conservative total mastectomy with axillary lymph-node dissection was thus performed. The histopathological diagnosis was the recurrence of invasive ductal carcinoma, arising mainly in the reticular layer of the dermis. Chemotherapy was administered postoperatively. There has been no evidence of recurrence as of 1 year after surgery.

Sevoflurane-induced pica in female rats.

We examined the effects of volatile anesthetics on pica, which can be used to assess nausea and vomiting in rats. We found that inhalation anesthesia with sevoflurane significantly induced pica in female but not male rats. Among the female rats, young rats (8 weeks old) were more susceptible to its induction than adult rats (20 weeks old) with ovariectomy or sham-surgery. Anti-emetic drugs that are used to prevent postoperative nausea and vomiting (PONV) inhibited the pica. These results suggest that sevoflurane-induced pica in young female rats has the potential to be an animal model of PONV in humans.

Synthesis and evaluation of N-alkyl-S-[3-(piperidin-1-yl)propyl]isothioureas: high affinity and human/rat species-selective histamine H(3) receptor antagonists.

S-Alkyl-N-alkylisothiourea compounds containing various cyclic amines were synthesized in the search for novel nonimidazole histamine H3 receptor (H3R) antagonists. Among them, four N-alkyl S-[3-(piperidin-1-yl)propyl]isothioureas 18, 19, 22, and 23 were found to exhibit potent and selective H3R antagonistic activities against in vitro human H3R, but were inactive against in vitro human H4R. Furthermore, three alkyl homologs 18-20 showed inactivity for histamine release in in vivo rat brain microdialysis, suggesting differences in antagonist affinities between species. In addition, in silico docking studies of N-[4-(4-chlorophenyl)butyl]-S-[3-piperidin-1-yl)propyl]isothiourea 19 and a shorter homolog 17 with human/rat H3Rs revealed that structural differences between the antagonist-docking cavities of rat and human H3Rs were likely caused by the Ala122/Val122 mutation.

Involvement of substance P and the neurokinin-1 receptor in radiation-induced hair loss in mice.

We investigated the involvement of substance P (SP) and the neurokinin-1 receptor (NK(1)R) in the development of radiation-induced hair loss in mice. A dose of 40 Gy of gamma irradiation induced hair loss from the 10th to at least the 60th day after irradiation. A specific NK(1)R antagonist, CP-99,994, significantly delayed radiation-induced hair loss and reduced its severity. Furthermore, gamma irradiation induced the expression of preprotachykinin-A, a precursor protein of SP, mRNA in irradiated murine skin on the 10th and 30th days after irradiation. These results indicated that gamma irradiation-induced hair loss was mediated by SP via NK(1)R.

Activation of orexinergic and histaminergic pathway involved in therapeutic effect of histamine H4 receptor antagonist against cisplatin-induced anorexia in mice.

We previously reported that hypothalamic tumor necrosis factor-alpha (TNF-α) mRNA expression via histamine H4 receptors contributes to the development of cisplatin-induced anorexia; however, its precise mechanisms remain unclear. It has been reported that chemotherapeutic agents induce the suppression of orexin neuron activity, and the administration of orexin inhibits chemotherapeutic agent-induced gastric discomfort. Other studies demonstrated that the central administration of TNF-α impairs the orexinergic system, and that orexin excites the histaminergic system. We investigated the involvement of orexinergic and histaminergic systems in the therapeutic effect of an H4 receptor antagonist against cisplatin-induced anorexia. Cisplatin decreased the expression of prepro-orexin mRNA, which encodes precursors of orexin, in the hypothalamus of mice. The period of expression decreased in parallel with the onset of anorexia, and treatment with an H4 receptor antagonist (JNJ7777120, 10 mg/kg) inhibited the decrease in expression. The effect of the H4 receptor antagonist on cisplatin-induced anorexia in mice was antagonized by an orexin OX2 receptor antagonist (JNJ10397049, 5 mg/kg) rather than an orexin OX1 receptor antagonist (SB408124, 30 mg/kg). Although an OX2 receptor agonist (YNT-185, 20 mg/kg) or a histamine H3 receptor inverse agonist (ciproxifan, 1 mg/kg) inhibited the cisplatin-induced anorexia, the inhibitory effect of the OX2 receptor agonist was antagonized by an H3 receptor silent antagonist (VUF5681, 5 mg/kg). The combination of JNJ7777120 (10 mg/kg) and ciproxifan (0.5 mg/kg) completely resolved the cisplatin-induced anorexia. These results suggest that activation of the orexinergic and histaminergic pathway is involved in the therapeutic effect of an H4 receptor antagonist against cisplatin-induced anorexia.

Involvement of the Hypothalamic Glutamatergic System in the Development of Radiation-Induced Pica in Rats.

Since the peripheral serotoninergic pathway is involved in the development of radiation-induced nausea and vomiting, referred to as radiation sickness, serotonin 5-HT3 receptor antagonists are used as a preventive measure, although patients still suffer from these symptoms. Glutamate is known as the excitatory neurotransmitter and is involved in various autonomic symptoms. We investigated the effect of radiation on glutamate release in rats, as measured by in vivo brain microdialysis, and the effects of glutamate receptor antagonists on radiation-induced pica, which can be used as a behavioral assessment of radiation sickness in rats. A microdialysis probe was inserted into the hypothalamus of rats that received 4 Gy total-body irradiation (TBI) with or without pretreatment of 5-HT3 receptor antagonist (granisetron, 0.1 mg/kg, i.p.), and dialysates were collected for 3 h after TBI and subjected to HPLC assay of glutamate. In addition, rats were intracerebroventricularly injected with NMDA receptor antagonist (MK-801: 3 µg/rat) or AMPA receptor antagonist (CNQX: 1 µg/rat) before TBI, and radiation-induced pica was determined. An increase in glutamate release was observed within 1 h postirradiation. The increased glutamate release was suppressed by granisetron. We also found that CNQX, but not MK-801, effectively inhibited radiation-induced pica. These results indicate that the hypothalamic glutamatergic system contributes to radiation-induced pica through the AMPA receptors.

Strain differences in the development of cisplatin-induced pica behavior in mice.

INTRODUCTION: Pica behavior, kaolin ingestion, in rats and mice can be used as an assessment of nausea and vomiting; however, we observed that the incidence of pica behavior in ICR strain mice varied markedly. We investigated the susceptibility of four strains of mice (ICR, BALB/c, C57BL/6, and DBA/2) to the development of pica behavior. METHODS: Mice received cisplatin (7.5 mg/kg, i.p.) with or without a serotonin 5-HT3 receptor antagonist (granisetron: 0.1 mg/kg, i.p.) or tachykinin NK1 receptor antagonist (fosaprepitant: 30 mg/kg, i.p.), and then their daily kaolin intake was measured for 2 days. We examined the expression of preprotachykinin (PPT)-A mRNA in the medulla of cisplatin-treated mice 8 and 32 h after drug administration. RESULTS: All mice except for ICR strain significantly increased kaolin intake after cisplatin administration. Among the tested strains, DBA/2 mice compared to BALB/c and C57BL/6 mice notably showed pica behavior on both days (P < 0.0001). The expression of PPT-A mRNA was significantly increased 8 h after cisplatin administration in all strains, but the increase remained on the second day only in DBA/2 mice (P < 0.05). Granisetron significantly inhibited pica behavior in DBA/2 mice on the first day (P < 0.0001), but not the second day; however, fosaprepitant completely inhibited the pica behavior on both days (P < 0.001). DISCUSSION: These results indicate that cisplatin-induced pica behavior in mice is likely to be influenced by the genotype, and that DBA/2 mice are useful to analyze the emetogenic or anti-emetic potential of drugs in preclinical studies.

Effects of a histamine H4 receptor antagonist on cisplatin-induced anorexia in mice.

Cancer chemotherapy often induces gastrointestinal symptoms such as anorexia, nausea, and vomiting. Antiemetic agents are effective in inhibiting nausea and vomiting, but patients still experience anorexia. We previously reported that chemotherapeutic agent-induced anorexia is associated with an increase of inflammatory cytokines. Other studies also reported that antagonism of the histamine H4 receptor is anti-inflammatory. In this study, we investigated the involvement of the H4 receptor in the development of chemotherapy-induced anorexia in mice. Cisplatin-induced anorexia occurred within 24 h of its administration and continued for 3 days. The early phase (day 1), but not the delayed phase (days 2 and 3), of anorexia was inhibited by the daily injection of a 5-HT3 receptor antagonist (granisetron). However, a corticosteroid (dexamethasone) or selective H4 receptor antagonist (JNJ7777120) abolished the delayed phases of anorexia. Cisplatin significantly increased TNF-α mRNA expression in the hypothalamus and spleen, and the period of expression increase paralleled the onset period of anorexia. In addition, pretreatment with JNJ7777120 completely inhibited the increased expression. These results suggest that TNF-α mRNA expression via H4 receptors may contribute to the development of cisplatin-induced anorexia, and that H4 receptor antagonists are potentially useful treatments.

The anti-cancer drug-induced pica in rats is related to their clinical emetogenic potential.

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.

Action of GLP-1 (7-36) amide and exendin-4 on Suncus murinus (house musk shrew) isolated ileum.

Glucagon-like peptide-1 (GLP-1) receptor agonists have been reported to modulate gastrointestinal motility but the mechanism is essentially unknown. In the present studies, we investigated the potency and mechanism of action of GLP-1 receptor ligands on the isolated ileum of Suncus murinus, an insectivore used in anti-emetic research. Ileal segments were mounted in organ baths containing Kreb's solution. Cumulative concentration-response curves to GLP-1 (7-36) amide (0.1-300 nM) and exendin-4 (0.1-100 nM) were constructed in the absence and presence of exendin (9-39) amide (0.3-3 nM). GLP-1 (7-36) amide and exendin-4 induced concentration-dependent contractions yielding pEC50 values of 8.4+/-0.2 and 8.4+/-0.4, respectively. Exendin (9-39) antagonized the action of both agonists in a non-competitive reversible manner, with apparent pKB values of 9.5 and 9.7, respectively. Tetrodotoxin (1 microM), atropine (1 microM) and hexamethonium (500 microM) were used to determine the contractile mechanism of action of exendin-4. Tetrodotoxin and atropine significantly antagonized (P<0.01) the contractile action of exendin-4 (10 nM); hexamethonium (500 microM) had no action. These studies suggest that GLP-1 receptor agonists contract the ileum indirectly via postganglionic enteric neurones and an involvement of muscarinic receptors. These studies provide information relevant to the use of this species to estimate the therapeutic indexes of GLP-1 receptor agonists.

Detection of Nausea-Like Response in Rats by Monitoring Facial Expression.

Patients receiving cancer chemotherapy experience nausea and vomiting. They are not life-threatening symptoms, but their insufficient control reduces the patients' quality of life. To identify methods for the management of nausea and vomiting in preclinical studies, the objective evaluation of these symptoms in laboratory animals is required. Unlike vomiting, nausea is defined as a subjective feeling described as recognition of the need to vomit; thus, determination of the severity of nausea in laboratory animals is considered to be difficult. However, since we observed that rats grimace after the administration of cisplatin, we hypothesized that changes in facial expression can be used as a method to detect nausea. In this study, we monitored the changes in the facial expression of rats after the administration of cisplatin and investigated the effect of anti-emetic drugs on the prevention of cisplatin-induced changes in facial expression. Rats were housed in individual cages with free access to food and tap water, and their facial expressions were continuously recorded by infrared video camera. On the day of the experiment, rats received cisplatin (0, 3, and 6 mg/kg, i.p.) with or without a daily injection of a 5-HT3 receptor antagonist (granisetron: 0.1 mg/kg, i.p.) or a neurokinin NK1 receptor antagonist (fosaprepitant: 2 mg/kg, i.p.), and their eye-opening index (the ratio between longitudinal and axial lengths of the eye) in the recorded video image was calculated. Cisplatin significantly and dose-dependently induced a decrease of the eye-opening index 6 h after the cisplatin injection, and the decrease continued for 2 days. The acute phase (day 1), but not the delayed phase (day 2), of the decreased eye-opening index was inhibited by treatment with granisetron; however, fosaprepitant abolished both phases of changes. The time-course of changes in facial expression are similar to clinical evidence of cisplatin-induced nausea in humans. These findings indicate that the monitoring of facial expression has the potential to be useful for the detection of a nausea-like response in laboratory animals.

Ondansetron, dexamethasone and an NK1 antagonist block radiation sickness in mice.

Radiation sickness is frequently observed in total body irradiation (TBI). We have reported that the kaolin ingestion behavior "pica" may be analogous to nausea and vomiting in mice. We evaluated the effects of anti-emetics on the prevention of radiation-induced pica in mice. After the intraperitoneal injection of ondansetron (OND: 2 mg/kg), dexamethasone (DEX: 2 mg/kg) or CP-99,994 (CP: 15 mg/kg), mice received 9 Gy of TBI, and then kaolin consumption was measured after 24 h. Radiation-induced pica was slightly inhibited by pretreatment with a single administration of OND or DEX, but not by CP (control: 0.69+/-0.19 g, OND: 0.33+/-0.06 g, DEX: 0.39+/-0.07 g, CP: 0.66+/-0.09 g); it was significantly inhibited by the combination treatment of OND and DEX (control: 0.55+/-0.09 g, OND+DEX: 0.30+/-0.06 g, OND+CP: 0.70+/-0.04 g, DEX+CP: 0.58+/-0.02 g). The combination of the three drugs completely abolished the behavior (control: 0.67+/-0.08 g, OND+DEX+CP: 0.10+/-0.05 g). These results suggest that radiation-induced pica in mice may be useful to evaluate drugs for treatment of radiation sickness and that the combination therapy of a serotonin 5-HT3 receptor antagonist and a glucocorticosteroid with a neurokinin NK1 receptor antagonist is effective in reducing the symptom.

Induction and antagonism of pica induced by teriparatide in rats.

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.