白花丹不同有机溶剂提取物和白花丹醌对移植性乳腺癌和S180肉瘤的作用

目的初步了解白花丹不同有机溶剂提取物和白花丹醌对BALB/C小鼠移植性EMT-6乳腺癌及KM小鼠移植性S180的作用。方法用动物移植性肿瘤在体实验法。结果①氯仿1g·kg-1剂量组、白花丹醌0.02g·kg-1组可抑制EMT-6乳腺癌在BALB/C小鼠体内生长,与生理盐水组比较,瘤重明显减轻(P<0.05),其抑制率分别为34.2%和41.2%。②氯仿1g·kg-1、0.5g·kg-1剂量组,石油醚1g.kg-1、0.5g·kg-1剂量组,乙酸乙酯1g·kg-1、0.5g·kg-1剂量组均可抑制S180肉瘤在KM小鼠体内生长,与生理盐水组比较,瘤重明显减轻(P<0.05或<0.01),其中以氯仿1g·kg-1剂量组抑制率最高(P<0.01),达55.6%。结论白花丹氯仿提取物、石油醚提取物、乙酸乙酯提取物和白花丹醌有一定抑制移植性EMT-6乳腺癌和S180肉瘤的作用,值得进一步深入研究。     

In vivo antitumor efficacy of CW252053, a folate-based thymidylate synthase inhibitor

Previous studies have demonstrated that CW252053, a quinazoline antifolate, exhibits potent inhibitory activity against thymidylate synthase (TS) as well as cytotoxic activity against tumor cell lines in vitro. In this study, we evaluated the in vivo antitumor efficacy of CW252053 in the mouse tumor model. Female B6D2F1 mice were injected with LY3.7.2C TK-/- (thymidine kinase deficient mouse lymphoma) cells into the gastrocnemius muscle. Then, CW252053 was administered twice daily by intraperitoneal injection for 10 days, and tumor growth was monitored daily by leg diameter measurement. All animals in the vehicle, 5-FU, and low dose (30 mg/kg) CW252053 treated groups died between days 12 and 23 because of the tumor burden. In contrast, dosing with 60 mg/kg of CW252053 produced a cure rate against tumor growth of 37.5% and a survival rate of 50%. Even more significantly, a higher dose of CW252053 (120 mg/kg) elicited both a 100% cure rate and a 100% survival rate at the termination of the study, confirming that this compound has very potent in vivo antitumor activity against tumor growth. During the experimental period of this study no signs of toxicity were observed even at the high CW252053 dosage rate of 120 mg/kg.     

In vivo micronucleus assay and GST activity in assessing genotoxicity of plumbagin in Swiss albino mice

Information available on the mutagenicity of a large number of indigenous drugs commonly employed in the Siddha and Ayurveda systems of medicine is scanty. In this context, the current investigation on plumbagin, 5-hydroxy-2methyl-1,4-napthoquinone, an active principle in the roots of Plumbago zeylanica used in Siddha and Ayurveda for various ailments, was carried out; 16 mg/kg b.w. (LD(50)) was fixed as the maximum dose. Subsequent dose levels were fixed as 50% and 25% of LD(50) amounting to 8 mg and 4 mg/kg b.w., respectively, and given orally for 5 consecutive days in 1% Carboxyl Methyl Cellulose (CMC) to Swiss albino mice weighing 25-30 g. The micronucleus assay was done in mouse bone marrow. Plumbagin was found to induce micronuclei at all the doses studied (4 mg/kg, 8 mg/kg, 16 mg/kg b.w.), and it proves to be toxic to bone marrow cells of Swiss albino mice. Animal treated with cyclophosphamide (40 mg/kg b.w.) served as positive control. In addition, glutathione S-transferase (GST) activity was observed in control, plumbagin (4 mg, 8 mg, 16 mg/kg b.w., respectively), and genotoxin-treated experimental group of animals. No significant change in GST activity was observed with plumbagin dose of 4 mg/kg b.w., whereas GST activity was significantly inhibited by higher doses of plumbagin (8 mg and 16 mg/kg b.w.) and cyclophosphamide.     

蝎毒的放射增敏实验研究

目的 探讨蝎毒对放疗的增敏效应及其作用机制。方法 将Ｌｅｗｉｓ肺癌细胞接种于ＮＩＨ小鼠右后肢外侧皮内，当肿瘤平均直径达到６ｍｍ左右时开始实验，观察蝎毒（０．６ｍｇ／ｋｇ）、放疗（４Ｇｙ）及其联合治疗组的肿瘤倍增时间（ＭＤＤＴ）、生存时间（ＡＳＴ）、病理改变和细胞凋亡变化。结果 对照组、蝎毒组、放疗组和蝎毒→放疗组的ＭＤＤＴ分别为（１０．２±０．３４）ｄ、（１１．５±０．３８）ｄ、（１３．７±０．４２）ｄ和（１６．１±０．５３）ｄ，各治疗组均可延长荷瘤小鼠生存期，引起肿瘤组织的坏死，诱发细胞凋亡，联合治疗效果更为突出。结论 蝎毒对荷Ｌｅｗｉｓ肺癌的ＮＩＨ小鼠瘤体不仅有抑制或杀伤作用，而且对放疗有增敏作用。诱发细胞凋亡是其抗肿瘤的主要机制之一。     

In Vivo Micronucleus Assay and GST Activity in Assessing Genotoxicity of Plumbagin in Swiss Albino Mice

Information available on the mutagenicity of a large number of indigenous drugs commonly employed in the Siddha and Ayurveda systems of medicine is scanty. In this context, the current investigation on plumbagin, 5-hydroxy-2methyl-1,4-napthoquinone, an active principle in the roots of Plumbago zeylanica used in Siddha and Ayurveda for various ailments, was carried out; 16 mg/kg b.w. (LD₅₀) was fixed as the maximum dose. Subsequent dose levels were fixed as 50% and 25% of LD₅₀ amounting to 8 mg and 4 mg/kg b.w., respectively, and given orally for 5 consecutive days in 1% Carboxyl Methyl Cellulose (CMC) to Swiss albino mice weighing 25–30 g. The micronucleus assay was done in mouse bone marrow. Plumbagin was found to induce micronuclei at all the doses studied (4 mg/kg, 8 mg/kg, 16 mg/kg b.w.), and it proves to be toxic to bone marrow cells of Swiss albino mice. Animal treated with cyclophosphamide (40 mg/kg b.w.) served as positive control. In addition, glutathione S-transferase (GST) activity was observed in control, plumbagin (4 mg, 8 mg, 16 mg/kg b.w., respectively), and genotoxin-treated experimental group of animals. No significant change in GST activity was observed with plumbagin dose of 4 mg/kg b.w., whereas GST activity was significantly inhibited by higher doses of plumbagin (8 mg and 16 mg/kg b.w.) and cyclophosphamide.     

Comparative stimulus properties of two fractions of the coca leaf (E. coca)

Male and female Wistar rats were trained to discriminate 5.0 mg/kg cocaine from 2.0 ml/kg saline using a two-bar food reinforcement (FR 30) drug discrimination paradigm. Once discrimination behavior had stabilized the subjects were tested (in extinction) with several doses of two different fractions of the coca leaf and four doses of cocaine HCl (1.0, 2.5, 7.5, 10 mg/kg). The fractions were prepared by extracting powderd coca leaves with 95% ethanol and then partitioning the residue between chloroform and water. Two doses of the water fractions (480, 960 mg/kg) and five doses of the chloroform fraction (7.5, 15, 30, 60, 120 mg/kg) were tested. The water fraction was devoid of cocaine while the five doses of the chloroform fraction contained cocaine equivalent to 0.4, 0.83, 1.65, 3.3 and 6.6 mg/kg, respectively, as determined by gas chromatographic saline. The water fraction at 480 mg/kg generalized to saline; however following pretreatment with the 960 mg/kg dose of this fraction, the animals failed to respond. The two largest doses of the chloroform fraction (60 and 120 mg/kg) generalized to cocaine while the other three doses did not. The 7.5 mg/kg dose generalized to saline; the 15 and 30 mg/kg doses engendered an intermediate level of responding on both the cocaine and saline lever.     

In vivo antitumor effects of bitter principles from the antlered form of fruiting bodies of Ganoderma lucidum

Two triterpene fractions and a single ganoderma alcohol obtained from an antlered form of the fruiting bodies of Ganoderma lucidum were examined for their antitumor effects on the growth of inoculated mouse Lewis lung carcinoma in mice by intraperitoneal administration. The ganoderma alcohol fraction significantly suppressed the tumor growth at doses of 50 and 100 mg/kg in the treatment period, and even after the administration, showing antitumor activity with a T/C value of 70.6% at a dose of 100 mg/kg. On the other hand, no obvious activity was shown at each dose in the ganoderma-acid-fraction-treated groups. Furthermore, ganoderiol F, which exhibited the strongest cytotoxicity against four tumor cell lines among five ganoderma alcohols examined, remarkably inhibited the tumor growth, accounting for 63.7% and 78.7% of control group at a dose of 5 mg/kg, 54.1% and 63.0% at a dose of 10 mg/kg, and 47.7% and 53.9% at a dose of 20 mg/kg in and after the administration period, respectively, in a dose-dependent manner. These results suggest that the antitumor effects of bitter principles in G. lucidum are mainly due to ganoderma alcohols.     

Enhancement of radiation effect by Aphanamixis polystachya in mice transplanted with Ehrlich ascites carcinoma

The effect of radiation on tumor tissue can be optimized by adding radiosensitizing agents, in order to achieve a greater degree of tumor damage than expected from the use of either treatment alone. The ethanolic extract of Aphanamixis polystachya (APE) was tested in Swiss albino mice transplanted with Ehrlich ascites carcinoma (EAC) and exposed to various doses of gamma-radiation. EAC mice received 0, 10, 25, 50, 75, 100, 150 or 200 mg/kg body wt APE before exposure to 6 Gy gamma-radiation followed by once daily administration for another 8 consecutive days post-irradiation. The optimum radiosensitizing dose was found to be 50 mg/kg APE that was further tested in EAC mice exposed to 0, 1, 2, 4, 6 or 8 Gy hemi body gamma-radiation. The best effect of APE and radiation was observed for 6 Gy gamma-radiation. The splitting of 50 mg into two equal fractions of 25 mg and administering the split dose with a gap of 8 h on 1, 3, 5, 7 or 9 d of tumor inoculation resulted in an increased survival even when the drug was administered at late stages (day 5) of tumor development. The APE treatment before irradiation elevated lipid peroxidation followed by a reduction in the glutathione contents. Treatment of tumor bearing mice with APE before irradiation further reduced the activities of various antioxidant enzymes like glutathione peroxidase, glutathione-s-transferase, superoxide dismutase and catalase at different post last drug administration (PLDA) times.     

Short-term oral administration of polybrominated biphenyls enhances the development of hepatic enzyme-altered foci in initiated rats

FireMaster BP-6 (FM), a commercial mixture of polybrominated biphenyls (PBB), has been shown to act as a tumor promoter in hepatocarcinogenesis assays in rats. Most hepatic tumor promoters must be administered for many weeks or months. Because FM is highly persistent in animal tissues, it was hypothesized that very short-term administration of FM would result in tumor promotion. Female Sprague-Dawley rats weighing 185-215 g were initiated by a two-thirds partial hepatectomy followed by 10 mg diethylnitrosamine/kg body weight (BW) 24 h later. Thirty days later, rats were gavaged with FM in corn oil, at total doses of 0, 13, or 130 mg FM/kg BW. Half the dose was given on d 30, and the remaining half was given 24 h later. At 120 d after gavage the rats were killed and necropsied. Five liver sections from each animal were histochemically stained for gamma-glutamyl transpeptidase-positive enzyme-altered foci (EAF). EAF were significantly increased over control values in initiated rats given 130 mg FM/kg. In animals given 13 mg FM/kg, EAF were increased to a lesser extent but not significantly above controls. Enhancement of these EAF in initiated rats reflects tumor-promoting activity. In this study, 24-h administration of FM in initiated rats was sufficient to enhance hepatic EAF measured 120 d later in an rats was sufficient to enhance hepatic EAF measured 120 d later in an initiation-promotion protocol, and a dose of 13 mg FM/kg was apparently close to a possible no-effect threshold level for enhancement of EAF.     

Contribution of planar (0-1 ortho) and nonplanar (2-4 ortho) fractions of Aroclor 1260 to the induction of altered hepatic foci in female Sprague-Dawley rats

The hepatic tumor promoting activity of the planar 0-1 ortho ( approximately 9.7% w/w) and the nonplanar 2-4 ortho ( approximately 90.3% w/w) fraction of the commercial PCB mixture Aroclor 1260 was studied using a medium-term two-stage initiation/promotion bioassay in female Sprague-Dawley rats. Fractionation was carried out on an activated charcoal column. The composition of the effluent from the column was tested by GC-ECD. The absence of planar compounds in the 2-4 ortho fraction was confirmed by GC-MS analysis. The dioxin-like toxic potency of the fractions was determined with the DR-CALUX assay. The animal experiment was started with the initiation procedure (diethylnitrosamine injection, 30 mg/kg body wt ip, 24 h after (2)/(3) hepatectomy), followed 6 weeks later by the promotion treatment, which consisted of a weekly subcutaneous injection during 20 weeks. Exposure groups (n = 10) received the following treatments (dose/kg body wt/week): Aroclor 1260 (10 mg), 0-1 ortho fraction (0.97 mg), 2-4 ortho fraction (1, 3, or 9 mg), a reconstituted 0-4 ortho fraction (9.97 mg), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153; 1 or 9 mg), 2,3,7,8-TCDD (1 microg; positive control) or corn oil (1 ml; vehicle control). One group did not receive a promotion treatment. All exposure groups exhibited a significantly increased volume fraction of the liver occupied by hepatic foci positive for the placental form of glutathione-S-transferase-p compared to the corn oil control, except for the groups treated with 0-1 ortho fraction and 1 mg PCB 153/kg body wt/week. Approximately 80% of the total tumor promoting capacity of the reconstituted 0-4 ortho fraction could be explained by the 2-4 ortho PCB fraction while the 0-1 ortho fraction had only a negligible contribution. These results suggest that the majority of the tumor promotion potential of PCB mixtures resides in the non-dioxin-like fraction, which is not taken into account in the toxic equivalency factor (TEF) approach for risk assessment of PCBs. This may result in an underestimation of the tumor promotion potential of environmental PCB mixtures.     

白花丹醌和亚砷酸对白血病荷瘤小鼠作用的比较。

目的观察白花丹醌对白血病异种移植瘤的体内作用。方法用NB4细胞构建白血病小鼠模型,白花丹醌组(2mg/(kg.d)),亚砷酸组(4mg/(kg.d)),分别腹腔给药15d,计算抑瘤率,凋亡指数(AI)并进行病理组织学检查。结果白花丹醌组抑瘤率为40.49%(P<0.01),AI为(8.52±1.49)%(P<0.01),未出现明显的病理组织损伤。亚砷酸组则无明显的抑瘤作用,凋亡作用不明显(P>0.05),部分伴有心肌组织的损伤。结论 :白花丹醌具有抑制肿瘤生长,诱导凋亡的作用,可能成为白血病治疗的新选择。     

Polysaccharides isolated from Ganoderma lucidum occurring in Southern parts of India, protects radiation induced damages both in vitro and in vivo

The in vivo and in vitro radioprotective property of the polysaccharides isolated from Ganoderma lucidum were determined by survival studies, induction of micronucleus in reticulocytes of mice, strand breaks in plasmid pBR322 DNA and inhibition of lipid peroxidation (TBARS assay). Polysaccharides were administered as a single dose after whole body exposure to 10 Gy ⁶⁰Co γ-radiation to Swiss albino mice. At a dose of 500 μg/kg body wt, the polysaccharides were most effective in protecting animals from radiation induced loss of lethality. Administration of 500 μg/kg body wt to animal exposed to 10 Gy gamma radiation resulted in more than 60% survival on the 30th day compared to the dose of 300 mg/kg/body wt administration of amifostine, a clinically used radioprotective drug. The induction of micronuclei was reduced by the administration of polysaccharides. The decrease in micronuclei induction was dose dependent. Thus following 4 Gy exposure the micronuclei in polychromatic erythrocytes (MNCE) was reduced from 28.16 ± 3.049 to 16.0243 ± 2.074 and 6.30 ± 2.422 by polysaccharides at doses of 250 μg/kg body wt and 500 μg/kg body wt, respectively, and to 10.4 ± 2.581 by amifostine at a dose of 300 mg/kg body wt. The results indicate the significant protective effect of Ganoderma polysaccharides against radiation induced damages. The findings thus suggest the potential use of Ganoderma polysaccharides as novel radioprotective agent.     

The induction of hepatocellular neoplasia by trichloroacetic acid administered in the drinking water of the male B6C3F1 mouse

The prevalence (percent of animals with a tumor) and multiplicity (number of tumors per animal) of hepatocellular neoplasia in the male B6C3F1 mouse exposed to trichloroacetic acid (TCA) in the drinking water were determined. Male mice were exposed to 0.05, 0.5, and 5 g/L TCA for 60 wk (Study 1), to 4.5 g/L TCA for 104 wk (Study 2) and to 0.05 and 0.5 g/L TCA for 104 wk (Study 3). Time-weighted mean daily doses measured for the low, medium, and high dose groups were consistent over the three studies, 6-8, 58-68, and 572-602 mg/kg-d for the 0.05, 0.5, and the 4.5-5 g/L treatment groups, respectively. No significant changes in animal survival were noted across the studies. A significant increase in the prevalence and multiplicity of hepatocellular tumors was found in the 58-68 and 572-602 mg/kg/d TCA dose groups. Nonhepatoproliferative changes (cytoplasmic alterations, inflammation, and necrosis) in mice treated with TCA were mild and dose related. A TCA-induced increase in liver palmitoyl CoA oxidase activity, a marker of peroxisome proliferation, correlated with tumor induction. A linear association was found between peroxisome proliferation and tumor induction. Sporadic increases in the labeling index of nuclei outside of proliferative lesions were observed at carcinogenic doses throughout the studies. Given that there are no compelling data demonstrating genotoxic activity of either TCA or any metabolite, data are consistent with an epigenetic mode of action. The studies provide dose-response data on the development of hepatocellular neoplasia in male mice over a lifetime exposure to TCA. A no-observed-effect-level (NOEL) of 6 mg/kg/d was calculated for neoplastic and nonproliferative liver pathology.     

非小细胞肺癌三维适形放疗的临床分析

目的分析3DCRT及联合化疗在非小细胞肺癌治疗中疗效、放射损伤情况和预后情况。方法 63例符合入组标准的Ⅰ～Ⅲ期NSCLC患者纳入本研究,27例为单纯放疗,放疗中单次剂量中位值为2Gy(1.8～4.0Gy),5次/周,中位总剂量65Gy(60～112Gy),95%的PTV得到处方剂量。中位随访期13个月。不进行区域淋巴结预防性照射。CTV照射60Gy(2Gy/次,1次/d,5d/周)后GTV剂量递增,2～5Gy/次,递增次数为3～11次。36例合并化疗,化疗方案以铂类为基础,主要方案包括NP方案和TP方案。结果全组病例完全缓解27.0%(17/63),部分缓解65.1%(41/63),稳定7.9%(5/63),有效率为92.1%;全组1、2年总生存率为57.1%和38.1%,中位生存期14个月。放疗组和放化疗组1、2年生存率分别为50%和15.4%、63.9%和30.6%。中位生存期分别为15个月和11个月,两组比较差异有统计学意义(x2=7.567,P=0.006)。单因素和多因素分析未显示不良因素。结论 3DCRT联合化疗安全有效,两者的联合应用能够提高NSCLC的临床疗效,较单放组有更好的近期疗效,放化疗组在无明显增加放射副反应的基础上,1、2年生存期延长。同步放化疗组放射损伤可耐受,放射治疗剂量有提升空间,值得进一步研究。     

Antitumor promoting effect of an active component of Polyporus, ergosterol and related compounds on rat urinary bladder carcinogenesis in a short-term test with concanavalin A

The effect of fractions from a water extract of Polyporus on bladder tumor promotion was examined using 5% sodium saccharin (SS) in a short-term test with concanavalin A (Con A) in Wistar rats. Rats were given N-butyl-N-(4-hydroxybutyl) nitrosamine (BHBN) in drinking water for one week, and then promoter alone or test samples (given orally) plus promoter was administered for 3 weeks. Treatment with the BuOH fraction isolated from the water extract showed a strong inhibitory effect against the promoter. It was found that the inhibitory effect of the BuOH fraction is due to the effect of ergosterol contained in the fraction. Treatment with ergosterol showed a strong inhibitory effect against 5% SS, 0.01% BHBN, 3% DL-tryptophan (Trp) or 2% butylated hydroxyanisole (BHA); ID50 was 1.4 microg/kg/d, 2.9 microg/kg/d, 11.6 microg/kg/d, and 11.7 microg/kg/d against SS, BHBN, Trp and BHA, respectively. We also examined the effect of steroids and related compounds. Squalene and vitamin D2 showed strong inhibitory effect against 5% SS-induced bladder tumor promotion. These results strongly suggest that ergosterol could provide significant protection against the promotion of bladder tumor induced by many types of promoters in the environment.     

鹿茸有效成分对小鼠肝脏RNA和蛋白质合成的影响

多次给小鼠po鹿茸多胺30mg/kg,对[³H]leucine和[³H]uridine掺入肝组织蛋白和RNA有明显的促进作用,而庸茸非多胺则无此作用;当腐胺剂量为21mg/kg时,不仅促进[³H]leucine和[³H]uridiae掺入肝组织蛋白和RNA,也促进[³H]uridine掺入肝细胞核的RNA中,并增强RNA聚合酶的活性;精脒在剂量为8mg/kg时,仅对[³H]leucine掺入肝组织蛋白有促进;而精胺在1mg/kg时,没有观察到上述各种现象。此结果提示,鹿茸多胺类物质是鹿茸中刺激小鼠肝组织蛋白和RNA合成的主要活性物质,这 种刺激小鼠肝组织蛋白和RNA合成效应是由于鹿茸多胺能够显著地增强RNA聚合酶的活性。     

Repeated administration of histamine improves memory retrieval of inhibitory avoidance by lithium in mice

The influence of repeated administration of histamine on lithium-induced state dependency has been investigated. A single-trial step-down inhibitory avoidance task was used to assess memory in adult male NMRI mice. Intraperitoneal (i.p.) administration of lithium (10 mg/kg), immediately after training (post-training), impaired inhibitory avoidance memory on the test day. Pre-test administration of lithium reversed amnesia induced by the drug given after training, with the maximum response at a dose of 10 mg/kg. Repeated intracerebroventricular (i.c.v.) administration of histamine (20 microg/mouse) for 3 consecutive days followed by 5 days of no drug treatment improved memory retrieval of inhibitory avoidance by a pre-test lower dose (5 mg/kg i.p.) of lithium. In contrast, 3 days of i.c.v. injections of both the histamine H1 receptor antagonist pyrilamine (40 microg/mouse) and the histamine H2 receptor antagonist ranitidine (6.25 and 12.5 microg/mouse) prevented the improving effect of pre-test lithium (10 mg/kg i.p.) on memory retrieval. The results suggest that the repeated administration of histaminergic agents may induce a sensitization which affects the memory impairment induced by lithium.     

A novel plasmin-inhibitor inhibits the growth of human tumor xenografts and decreases metastasis number

The novel plasmin inhibitor YO-2, which also exerts an apoptosis-inducing effect on various human tumor cell cultures, was examined regarding its tumor growth inhibitory and antimetastatic action. The tumor growth inhibitory effect of YO-2 was studied using HT-29 human colon carcinoma, HT-18 human melanoma and HT-58 human B cell lymphoma inoculated as xenografts into immuno-deprived mice. Antimetastatic activity was tested on the B16 mouse melanoma muscle-lung model. YO-2 inhibited the growth of all xenografts in the range of 40-50%, when administered s.c. at a dose of 2.0 mg/kg (HT-29, HT-58) or orally at a dose of 0.4 mg/kg (HT-18). YO-2 decreased the number of lung metastasis found in mice inoculated i.m. with B16 melanoma, 4 mg/kg being the most effective. Since YO-2 is the only plasmin inhibitor having antihemorrhagic and also antitumor effect, this compound could be rationally used in combination therapy of neoplastic disease, especially when hemorrhage aggravates the course of the disease.     

Effect of reserpine on the subcellular distribution of 3H-α-methylnoradrenaline in the mouse heart

1. Mice were injected with reserpine (0.5 mg/kg or 2.5 mg/kg) at various intervals after an intravenous injection of (3)H-alpha-methylnoradrenaline ((3)H-alpha-MeNa), 20 mug or 100 mug/kg. The effect of reserpine on the content of labelled amine in the subcellular fractions of the heart was studied.2. In most experiments reserpine caused a pronounced decrease in the (3)H-alpha-MeNA content of the particulate fraction (P). The decrease was most pronounced when the higher dose of reserpine and lower dose of alpha-MeNA were used. In most experiments, the (3)H-alpha-MeNA content of the supernatant fractions was unchanged and, therefore, the P/(P + S) ratio was decreased.3. It is concluded that the effect of reserpine is a releasing effect on the particulate (granular) fraction, probably by blocking the re-uptake of the amine leaked from the granules. No support was found for the hypothesis that reserpine acts by inhibition of release of amines from the nerve granules.     

Tissue distribution and hepatic subcellular distribution of perfluorooctanoic acid at low dose are different from those at high dose in rats

Fate of perfluorooctanoic acid (PFOA) after an intravenous injection to male rats at the dose of 0.041 mg/kg body weight was compared with that at the dose of 16.56 mg/kg body weight. In the liver, 52% and 27% of PFOA dosed was recovered 2 h after an intravenous injection at the low and the high doses, respectively. By contrast, larger proportion of PFOA dosed was distributed to serum, other tissues and carcass at the high dose compared with the low dose. Subcellular distribution of PFOA was determined in the liver. At the dose of 0.041 mg/kg, 45%, 34%, 18% and 3% were distributed to 8000 g pellet, 18000g pellet, 105000g pellet and 105000g supernatant fraction, respectively; 28%, 17%, 13% and 43% of PFOA were distributed to these fractions, respectively, at the dose of 16.56 mg/kg. The higher the concentration of hepatic PFOA was, the more the PFOA was distributed to 105000g supernatant fraction. Biliary excretion index increased as PFOA concentration raised in the liver. These results suggest that PFOA is preferentially taken-up by the liver, and distributed to membrane fractions, especially 18000g pellet, and hardly excreted into bile when exposed at very low dose.