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F Furukawa

Publications and source records attributed to F Furukawa.

At least 19 recordsLinked to original sources

Male New Zealand Black/KN mice: a novel model for autoimmune-induced permanent alopecia?

BACKGROUND: Irreversible, permanent and scarring alopecia is associated with several autoimmune diseases, including all autoimmune connective tissue disorders. The pathogenesis of autoimmune-induced permanent alopecia (APA) is still poorly understood, and instructive, simple mouse models for the study of APA are needed urgently. During the course of our studies in a well-established mouse model for chronic rheumatoid arthritis, the New Zealand Black/KN (NZB/KN) mouse, we noticed that ageing male NZB/KN mice developed spontaneous APA. OBJECTIVES: To study whether alopecia seen in ageing male NZB/KN mice displays key features of human APA and may, thus, be a useful new mouse model for clinically relevant APA research. METHODS: NZB/KN, the F1 hybrid of NZW/N Slc x NZB/KN (W/BKN F1), the F1 hybrid of NZB/KN x NZW/N Slc (BKN/W F1), and the F2 hybrid of W/BKN F1 x W/BKN F1 mice were employed in this study, in order to check which strain carries the highest risk of alopecia development. Besides routine histology, CD3, CD4 and CD8 expression as well as immunoglobulin (Ig) G and IgM deposition in hair follicles were investigated by immunohistology/immunofluorescence. Mast cell distribution/degranulation and Ki-67 (proliferation)/TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling) (apoptosis) positive cells were also analysed. RESULTS: Only F2 male NZB/KN mice were prone to develop alopecia, suggesting that Y chromosome-associated gene(s) are involved in the pathogenesis of APA, which incidence rises with increasing age. The lesional alopecia skin in 12-month-old male NZB/KN mice showed a sharp decline in hair follicle density, thus meeting a key criterion of permanent alopecia. Both macroscopically and histologically, the alopecia seen in these mice resembled in many respects different stages of clinical APA, such as alopecia associated with chronic discoid lupus erythematosus (DLE) in humans. Lesional APA hair follicles in mice displayed intrafollicular and perifollicular mononuclear cell infiltrates, as well as an increased number of activated (degranulated) perifollicular mast cells. In the fully developed lesion, many CD4+ cells were seen in perifollicular locations, including the epithelial stem cell region (bulge), and also contained a few CD8+ T cells. IgM deposits were found in the follicular basement membrane zone (BMZ). Both in the bulge and the hair matrix region of the affected anagen hair follicles, there were signs of massive keratinocyte apoptosis. CONCLUSIONS: Our currently available data suggest that male but not female NZB/KN mice may indeed represent a suitable mouse model for APA, with some similarities to the permanent alopecia seen in human DLE patients, although additional and confirmatory investigations are needed before this mouse strain can be accepted as a murine equivalent of APA in humans.

Aging↗

The effects of vitamin A derivative etretinate on the skin of MRL mice.

MRL/Mp-lpr/lpr (MRL/lpr) mice are characterized by the disorder of apoptosis due to defects in Fas antigens and autoimmune symptoms including spontaneous lupus erythematosus (LE)-like skin lesions. MRL/Mp- + / + (MRL/n) mice do not carry the defect of lpr mutation nor do they exhibit skin disorders during the first six months of life. Retinoids are known to inhibit the proliferation of skin fibroblasts, collagen synthesis, modulate immune responses, and apoptosis by Fas ligand upregulation in skin fibroblasts. We examined changes in dermal thickness and appearance of skin disorders in five months old MRL/lpr mice by oral treatment with etretinate, a retinoic acid derivative. Etretinate treated MRL/lpr mice did not have skin lesions or dermatopathological characteristics including an increase in cells infiltrating the dermis. The mean dermal thickness of MRL/lpr and MRL/n mice treated with etretinate decreased significantly and apoptotic cells density in the dermis of MRL/lpr mice with etretinate was significantly higher compared with the control group (P < 0.05) although MRL/lpr mice have a defect within the Fas antigen. We assumed that etretinate reduced dermal thickness, and suppressed the appearance of skin lesions by inducting apoptosis and perhaps regulation of cytokine expression.

Administration, Oral↗

Existence of a threshold for induction of aberrant crypt foci in the rat colon with low doses of 2-amino-1-methyl-6-phenolimidazo[4,5-b]pyridine.

Until recently it has been generally considered that genotoxic carcinogens have no threshold in exerting their potential for cancer induction. However, the nonthreshold theory can be challenged with regard to assessment of cancer risk to humans. In the present study we show that a food derived, genotoxic hepatocarcinogen, 2-amino-1-methyl-6-phenolimidazo[4,5-b]pyridine (PhIP), does not induce aberrant crypt foci (ACF) as preneoplastic lesions at low dose (below 50 ppm) or 8-hydroxy-2'-deoxyguanosine (below 400 ppm) in the rat colon. Moreover PhIP-DNA adducts were not formed at the lowest dose (below 0.01 ppm). Thus, the dose required to initiate ACF is approximately 5000 times higher than that needed for adduct formation. The results imply a no-observed effect level (existence of a threshold) for colon carcinogenesis by a genotoxic carcinogen.

8-Hydroxy-2'-Deoxyguanosine↗

Helicobacter pylori-positive patients with pruritic skin diseases are at increased risk for gastric cancer.

BACKGROUND: Helicobacter pylori infection has been implicated as a possible cause of extraintestinal disorders such as skin diseases. A number of case reports describe patients with skin diseases, such as prurigo nodularis, that are associated with gastric cancer. AIM: The aim of this study was to examine the prevalence of H. pylori infection and the incidence of gastric cancer in patients with pruritic skin diseases. METHODS: The patients were examined for circulating specific IgG antibodies against H. pylori in sera using ELISA. H. pylori-positive patients who were more than 40 years old underwent endoscopic screening for gastric cancer. RESULTS: We examined 134 patients with pruritic skin diseases, including 55 cases of cutaneous pruritus, 21 cases of prurigo chronica multiforme, 15 cases of nummular dermatitis and 43 cases of chronic urticaria. Early gastric cancer was detected in 2/36 (5.6%) patients with cutaneous pruritus and 3/16 (18.8%) with prurigo chronica multiforme. The prevalence of early gastric cancer was 5.6%, which was much higher than that among patients undergoing general endoscopic screening for gastric cancer. CONCLUSIONS: These results suggest that H. pylori-positive patients with pruritic skin diseases may be at increased risk for development of gastric cancer, and endoscopic screening in such patients is recommended.

Adult↗

Immunohistochemical staining of cutaneous tumours with G-81, a monoclonal antibody to dermcidin.

BACKGROUND: Recently, the novel antimicrobial peptide named dermcidin (DCD) was reported in human eccrine sweat glands. OBJECTIVES: We investigated the expression of DCD in a variety of cutaneous tumours in order to assess the usefulness of the monoclonal antibody (G-81), which recognizes a fragment of DCD. PATIENTS/METHODS: We studied the immunoreactivity of the G-81 antibody on 197 cutaneous tumours. RESULTS: A total of 13 of 26 cutaneous mixed tumours showed substantial immunoreactivity. In contrast all the following cases were completely unreactive: (i) epithelial tumours (seborrhoeic keratosis, squamous cell carcinoma, Bowen's disease, actinic keratosis, genital Paget's disease); (ii) follicular tumours (basal cell carcinoma, trichilemmoma, trichoepithelioma, trichoblastoma, keratoacanthoma, proliferating trichilemmal tumour, pilomatricoma); (iii) melanocytic tumours (malignant melanoma, naevus cell naevus, Spitz naevus, blue naevus); (iv) neural tumours (schwannoma, neurofibroma, Merkel cell neoplasm); (v) mesenchymal tumours (soft fibroma, dermatofibroma, dermatofibrosarcoma protuberans, vascular leiomyoma, leiomyosarcoma, lipoma, juvenile xanthogranuloma, angiomyoma); and (vi) other sweat gland tumours (poroid neoplasms, syringoma, cylindroma, clear cell hidradenoma, spiradenoma, syringoid eccrine carcinoma, mucinous carcinoma, apocrine cystadenoma, syringocystadenoma papilliferum, apocrine adenocarcinoma). Twenty-six cutaneous mixed tumours were considered from histopathological findings to be the apocrine type, but 13 of 26 mixed tumours contained some DCD-immunopositive cells that possibly differentiate into eccrine secretory glands. CONCLUSIONS: We found the expression of DCD in tubular structures of 50% of cutaneous mixed tumours with apocrine differentiation. These results suggest that a number of cutaneous mixed tumours show both eccrine and apocrine differentiation in the same neoplasm.

Antibodies, Monoclonal↗

Susceptibility of T cell receptor-alpha chain knock-out mice to ultraviolet B light and fluorouracil: a novel model for drug-induced cutaneous lupus erythematosus.

The anticancer agent 5-fluorouracil (FU) frequently induces cutaneous lupus erythematosus (LE) lesions on sun exposed sites. Based on this observation, we have tried to establish a cutaneous LE model of C57BL/6 J (B6) mice, B6 T cell receptor (TCR)-alpha(-/-) mice and B6 TCR-delta(-/-) mice treated with FU and/or ultraviolet B light (UVBL) in order to clarify the role of T cells and the cytokine profile of cutaneous lupus lesions. Cutaneous LE-like skin lesions could be induced in TCR-alpha(-/-) mice with low FU (0.2 mg) plus UVBL, and in B6 mice treated with a high dose of FU (2.0 mg) plus UVBL. In contrast, low FU plus UVBL induced such skin lesions in TCR-delta(-/-) mice at a very low incidence. Specifically, the skin lesions of TCR-alpha(-/-) mice with low FU plus UVBL appeared more rapidly and were more severe than lesions in B6 mice. The former had the common characteristic features of human chronic cutaneous LE such as typical histology, positive IgG at the dermoepidermal junction, low antinuclear antibody and low mortality. Furthermore, a Th1 response was induced in the development of drug-induced cutaneous LE. FU and UVBL-induced cutaneous LE-like eruption is an excellent model for better understanding the pathomechanisms of skin lesion development in LE.

Animals↗

A subchronic toxicity study of shea nut color in Wistar rats.

Shea nut color, obtained from nuts of the shea tree (Butyrospermum parkii), is used as a food-coloring agent. Flavonoid pigments are considered to be the responsible constituents. As there have been no reports of toxicological evaluation, a 13-week subchronic toxicity study was performed in Wistar Hannover rats at dose levels of 0 (control), 0.07, 0.31, 1.25 and 5% in powdered basal diet. The average of daily shea nut color intake was 51.3, 226.1, 986.8 and 3775.5 mg/kg/day for males and 56.4, 272.9, 1166.7 and 4387.7 mg/kg/day for females, respectively. During the administration period, daily observation of clinical signs and weekly measurement of body weights and food consumption were performed. After the end of the treatment, hematology, serum biochemistry, organ weight and histopathological examinations were conducted. No significant toxicological changes were observed in any parameters in this study. Hence, the no adverse effect dose of shea nut color was estimated to be greater than 5.0% for both sexes (3775.5 mg/kg/day for males and 4387.7 mg/kg/day for females).

Animals↗

Slow acetylator genotypes as a possible risk factor for infectious mononucleosis-like syndrome induced by salazosulfapyridine.

We report two patients with infectious mononucleosis-like syndrome induced by salazosulfapyridine (SASP). In both cases, high fever, skin rash, liver dysfunction and atypical lymphocytosis developed 3 weeks after initiating treatment with SASP. SASP is known to be mainly metabolized by N-acetyltransferase 2 (NAT2), and acetylation phenotypes (rapid, intermediate and slow acetylator) correlate with NAT2* genotypes. In our two patients, we investigated NAT2* genotypes by the polymerase chain reaction-restriction fragment length polymorphism method. We identified NAT2*6/*7 in one patient, and NAT2*6/*5 in the other, suggesting that both were slow acetylator phenotypes. In 20 healthy volunteers we found no slow acetylator genotypes. Genotyping prior to medication may be useful in evaluating patients with a high risk of severe systemic reaction to SASP.

Acetylation↗

Skin manifestations in acute arsenic poisoning from the Wakayama curry-poisoning incident.

BACKGROUND: Four people died and 63 others became ill after eating arsenic-laced curry served at a community festival in Wakayama, Japan, on 25 July 1998. Although dermatological manifestations after the acute ingestion of arsenic have seldom been documented, they were observed in 56% of the victims in the Wakayama curry-poisoning incident. OBJECTIVES: To characterize the skin manifestations due to acute arsenic poisoning. METHODS: Four of the 67 patients with arsenic poisoning died, and the remaining 63 patients served as subjects for this study. The dermatological findings were extracted from the medical charts at the institutions which admitted the victims, and from the results of a medical inquiry and examinations during a health screening 3 months after the incident. RESULTS: Dermatological findings were observed in 56% of the victims during the acute stage of poisoning. Facial oedema was observed in 13 patients, transient flushing erythema in five, conjunctival haemorrhage in 15, maculopapular eruptions in the intertriginous areas in eight, acral desquamation in 11, and herpesvirus infection in three. The histopathological findings of the maculopapular eruptions showed moderate to marked perivascular infiltration with endothelial swelling. Examination of 21 patients at 3 months after their exposure to arsenic revealed ungual changes including Mee's or Beau's lines in 17 cases, periungual pigmentation in nine, and acral desquamation in four cases. CONCLUSIONS: Our observations indicate that skin lesions are common in patients with acute arsenic poisoning; these findings may provide information of diagnostic significance.

Acute Disease↗

A chronic toxicity study of josamycin in F344 rats.

The chronic toxicity of josamycin was examined in Fischer 344 (F344) rats. Groups of 10 males and 10 females were given the test compound in the diet at concentrations of 0 (control), 0.02, 0.1, 0.5 or 2.5% for 52 weeks. Daily intake of josamycin was 0, 10, 50, 260 and 1310 mg/kg body weight in males and 0, 10, 60, 290 and 1460 mg/kg body weight in females, respectively. Body weight gain was significantly (P<0.05) reduced in the male 2.5% group but no noticeable changes were found in food intake. In hematological examination, the platelet count was significantly (P<0.01) lower in the male groups given 0.02% or more of josamycin and in the 2.5% female group as compared with the control group values in a dose-dependent manner. In serum biochemical examination, blood urea nitrogen was significantly (P<0.05 and P<0.01, respectively) higher in males given 0.5 and 2.5% and total bilirubin was significantly (P<0.05) higher in females receiving 2.5% as compared with those of the control group. No death occurred at any dose levels during the dosing period. At necropsy, with the exception of cecal enlargement in the groups given more than 0.1% josamysin and a significant (P<0.01) increase in the relative liver weight of females in the 2.5% group, no particular findings related to the administration were observed. Histopathologically, the incidence and severity of liver bile duct proliferation in female 2.5% group were significantly (P<0.01) greater than those of the control group. Other histological changes found in the treated and control groups were similar to the spontaneous lesions in this strain of rats in terms of the incidence and severity. Interestingly, the josamycin treatment reduced the development of altered liver cell foci in females in a dose-dependent manner. Thus, it is concluded that, under the present experimental conditions, josamycin induces bile duct proliferation in female F344 rats at a high dose of 1460 mg/kg body weight. Based on the decrease of platelet count found in males given 10 mg/kg body weight or more, the no-observed-adverse-effect level (NOAEL) was estimated to be less than 10 mg/kg body weight.

Animals↗

Spontaneous development of aberrant crypt foci in F344 rats.

Aberrant crypt foci (ACF) have been proposed as intermediate biomarkers for colon carcinogenesis on the basis of many rodent studies. Although molecular analyses have indicated that these lesions in experimental animals are related to early events in colon carcinogenesis, their preneoplastic nature has yet to be fully elucidated. In the present study, one hundred and thirty 19-week-old male Fischer 344 rats were examined. The biological characteristics of spontaneous ACF were analyzed histopathologically, immunohistochemically and with molecular biological techniques, and compared with colon tumors found in control groups used for carcinogenicity tests. The incidences of spontaneous ACF consisting of 1, 2, 3 and 4 or more crypts were respectively 27.7%, 32.5%, 16.8% and 22.8%. Most ACF were distributed in the lower middle and upper distal colon, and proximal colon ACF was rare. Likewise, ACF frequently (42.5%) developed in untreated animals, whereas the incidence of spontaneous colorectal tumors was extremely low (0.68%) in control male rats. In addition, spontaneous ACF did not show apparent proliferative activity or c-K-ras point mutations. Our results thus suggest that spontaneous ACF rarely progress to colon tumors although long-term sequential observation might be necessary to conclude the significance of ACF.

Adenocarcinoma↗

Essential similarities between spontaneous and MeIQx-promoted aberrant crypt foci in the F344 rat colon.

Aberrant crypt foci (ACFs) in the Fischer 344 (F344) rat colon, of control or 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx)-treated groups, were compared morphologically, immunohistochemically, and at the molecular biological level in order to elucidate their biological characteristics. Male 3-week-old rats were fed a diet supplemented with or without MeIQx at doses of 100 ppm or less for 16 weeks. The incidence of ACFs was the highest (90%) in animals given 100 ppm MeIQx but that in untreated rats was also surprisingly high (57%). Nine ACFs from nine MeIQx-treated rats and ten ACFs from ten untreated control rats were selected for detailed examination for their large size. There were no morphological differences in macroscopic and microscopic features between MeIQx-promoted and spontaneous ACFs. There were also no differences in immunohistochemical labeling for proliferating cell nuclear antigen (PCNA) and p53 protein between these ACFs although in both cases labeling was higher than in normal crypts. Dot blot hybridization revealed no c-K-ras mutations in codon 12 except in one ACF (11.1%) developing in a rat treated with 100 ppm MeIQx, in which a GGT-->GAT single base substitution was detected. Our results thus suggest that in terms of morphology, cell proliferation, P53 expression and c-K-ras mutation, most ACFs found in rats given 100 ppm MeIQx are essentially identical to their spontaneous counterparts.

Animals↗

Oral toxicity of a tocotrienol preparation in rats.

Tocotrienols are added as antioxidants to food. As there have been no reports of toxicological evaluation, a 13-week oral toxicity study was performed in Fischer 344 rats of both sexes at dose levels of 0 (group 1), 0.19 (group 2), 0.75 (group 3) and 3% (group 4) of a preparation in powdered diet. Suppression of body weight gain was observed in group 4 males. On hematological examination, significant decrease in mean corpuscular volume (MCV) was observed in all treated males. Platelets were significantly reduced in group 3 and 4 males. Hemoglobin concentration, MCV, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration were significantly decreased in group 3 and 4 females and hematocrit in group 4 females. On serum biochemical examination, increase in the albumin/globulin ratio (A/G) and alkaline phosphatase in all treated males, elevated alanine transaminase in group 4 of both sexes and increases in asparagine transaminase and gamma-glutamyl transaminase in group 4 females were observed. With regard to relative organ weights, liver weights in group 4 of both sexes and adrenal weights in all treated males demonstrated an increase, and ovary and uterus weights in group 4 females were reduced. Histopathologically, slight hepatocellular hypertrophy in group 3 and 4 males, and reduction of cytoplasmic vacuolation in the adrenal cortical region in group 4 males were observed. Because of pathological changes in male liver and hematological changes in females, the no-observed-adverse-effect level (NOAEL) was concluded to be 0.19% in the diet (120 mg/kg body weight/day for male rats and 130 mg/kg body weight/day for female rats). As a decrease in MCV, an increase in the A/G, elevation of alkaline phosphatase and increase in adrenal weight were observed in all treated males, a no-observed-effect level (NOEL) could not be determined in this examination.

Administration, Oral↗

Involvement of lipid peroxidation in spontaneous pancreatitis in WBN/Kob rats.

To cast light on the mechanisms underlying development of spontaneous pancreatitis lesions, tissues from WBN/Kob rats at various ages were histopathologically and immunohistochemically investigated with special reference to the existence of the lipid peroxidation products 4-hydroxy-2-nonenal (HNE), 4-hydroxy-2-hexenal (HHE), and malondialdehyde (MDA). Male 4-20-week-old WBN/Kob rats were killed to allow sampling of pancreatic tissues, which were fixed in cold acetone and 10% neutral-buffered formalin. and then processed for routine histopathology as well as immunohistochemistry for proteins modified by HNE, HHE, and MDA. Although no remarkable histologic changes were noted in younger animals, edema, hemorrhage, inflammatory cell infiltration, fibrosis, vacuolation of acinar cells, and ductular proliferation were observed in exocrine pancreatic tissue from animals at 10-15 weeks of age. In animals aged 20 weeks, the lesions had progressed remarkably and deposits of hemosiderin were apparent with fibrosis. Immunohistochemical examination for lipid peroxidation product-modified proteins showed HNE and MDA to be negative in all pancreatic tissues, but HHE was positive in the areas involving atrophy of acinar cells and fibrosis in the islets. The results of the present study thus provide support for the conclusion that lipid peroxidation during spontaneous pancreatitis in WBN/Kob rats may possibly be involved in the development of diabetes in this model.

Aging↗

Skin metastasis of neuroendocrine carcinoma derived from the mediastinum.

We report a 46-year-old Japanese man with a metastatic skin tumor on his left palmar region. He underwent resection for a mediastinal neuroendocrine carcinoma in February of 1998. After the operation, he immediately noticed an elevated tumor on his left palm. In September 1999, a brain tumor was discovered. The skin and brain tumors were subsequently removed surgically. Neuron specific enolase (NSE) in the serum was elevated to 25 ng/ml. A skin biopsy specimen from the left palmar site revealed multiple tumor nests which showed the same histological features as the primary mediastinal tumor. Immunostaining was positive for chromogranin, synaptophysin, and NSE but negative for S-100 protein and CD57. To our knowledge, this is the first report of cutaneous metastasis of a neuroendocrine tumor derived from the mediastinum.

Carcinoma, Neuroendocrine↗

Reporter gene transgenic mice as a tool for analyzing the molecular mechanisms underlying experimental carcinogenesis.

Carcinogenic compounds are classified into 2 categories, genotoxic and non-genotoxic, which are basically judged from in vitro genotoxicity data. However, it is well documented that genotoxicants do not necessarily exert in vivo carcinogenicity in rodents, partly because of a discrepancy between in vitro and in vivo mutagenicities. Recently, transgenic animal models with reporter genes such as lacI, lacZ and gpt have been developed as a tool for assessing in vivo mutagenicity as well as carcinogenicity. In this article, data using lacI transgenic mice and gpt delta mice are presented and their application is discussed. In lacI transgenic mice, dimethylnitrosamine (DMN) treatment significantly increased lacI mutant frequency (MF) in the liver, kidenys and lungs, but not in other non-target organs. Repeated dose ip administration of DMN was more effective than single dose treatment in the induction of lacI MF. The spectrum of mutant plaques induced by DMN was characterized by deletions as well as GC to AT base transitions. The remaining mice receiving DMN proved to have liver adenomas at a high frequency after 78 weeks. Meanwhile, dietary 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MelQx) significantly increased lacI and gpt MFs in the liver and colon. The characteristic spectrum of mutant plaques induced by MeIQx was a GC to TA base transversion in both the lacI and gpt mutations. Our results thus strongly suggest that these reporter gene transgenic animal models could offer a useful tool for analyzing molecular mechanisms underlying experimental carcinogenesis and for assessing the carcinogenic risk of environmental chemicals.

Animals↗

[Renal cell carcinoma in the Birt-Hogg-Dubé syndrome: report of a case].

Birt-Hogg-Dubé (BHD) syndrome is a rare dermatological condition appearing with an autosomal dominant mode of inheritance. It was first reported in 1977 by Birt et al. and 28 cases have been reported since then. BHD syndrome is characterized by asymptomatic dome-shaped, skin-colored papules on the face and upper trunk. Recently, various neoplasms have been reported to associate with BHD syndrome, including three familial and one sporadic cases of renal tumors. We report another sporadic case with renal tumor. A 53-year-old woman complained of gross hematuria and visited our institute on November 1996. She visited the Department of Dermatology, Wakayama Medical College because of skin lesions on the face and upper trunk at her age of 44. These skin lesions were present since her mid twenties. Her daughter also had similar skin lesions and visited the same Department. There was no family history of renal tumor. The patient was diagnosed to have a right renal tumor, and radical nephrectomy was performed. Pathological diagnosis was renal cell carcinoma, papillary type. She underwent interferon injection therapy postoperatively, but died because of lung metastases on April 1997. This is the first reported case of renal tumor occurring in BHD syndrome in Japan.

Carcinoma, Renal Cell↗

Modifying effects of 4-phenylbutyl isothiocyanate on N-nitrosobis(2-oxopropyl)amine-induced tumorigenesis in hamsters.

The modifying effects of dietary 4-phenylbutyl isothiocyanate (PBITC), given during the initiation stage of carcinogenesis, were investigated in hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). A total of 120 female 5-week-old hamsters were divided into six groups. Animals in groups 1-3, each consisting of 30 hamsters, were given BOP by two subcutaneous injections, 1 week apart, at a dose of 20 mg/kg body weight, plus 0, 10 or 100 micromol/animal of PBITC in corn oil by gavage 2 h prior to each carcinogen treatment. Ten animals in group 4 served as a vehicle control, and animals in groups 5 and 6, each consisting of ten hamsters, were given 10 and 100 micromol of PBITC alone in corn oil. Sacrifice was 52 weeks after the first BOP injection. The PBITC treatments significantly (P<0.05) inhibited the development of pancreatic ductal dysplasias and adenocarcinomas. Also, lung tumors (adenomas and adenocarcinomas) were significantly (P<0.05) reduced in a dose-dependent manner. In contrast, both hepatocellular and cholangiocellular tumors (adenomas and carcinomas) tended to be or were significantly increased by PBITC. These results, taken together with our previous findings, indicate that the natural isothiocyanate, phenethyl isothiocyanate (PEITC), has a more potent chemopreventive action against BOP-induced tumorigenesis than synthetic isothiocyanates with longer alkyl chains, such as 3-phenylpropyl isothiocyanate (PPITC) and PBITC. Thus, their lipophilicity does not necessarily reflect the chemopreventive potential because the strength of lipophilicity is PEITC<PPITC<PBITC.

Adenocarcinoma↗