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PubMed2004

[Soluble sugar content of clonal plant Neosinocalamus affinis at module and ramet levels].

In this paper, soluble sugar content of Neosinocalamus affinis was measured by anthrone colorimetry at two levels of module and ramet in order to reveal its ecological and physiological adaptability. The results showed that soluble sugar content decreased in the order of leaf > branch > culm. As for soluble sugar content, different modules responded to ramet age and position in different ways. The branch and culm of 1-year-old ramets contented more soluble sugar than those of other four ages, but soluble sugar content in leaf was independent to ramet age. For leaf and culm, lower parts of ramet contented more soluble sugar than middle and upper parts. Under high irradiance, the soluble sugar content of Neosinocalamus affinis leaf was more than that under low irradiance. Seasonal change had significant effect on soluble sugar content. The soluble sugar content of leaf presented a monthly change, with a bottom and upper value in January and in April, respectively, but there was no obvious difference between 2-year-old and 3-year-old ramets. The soluble sugar content of parent ramet leaves was positively correlative to that of daughter ramet in upper and middle parts of ramets. There was no significant difference between ramet ages at ramet level. Hierarchical response of physiological character to environmental changes existed at the module and ramet levels of Neosinocalamus affinis.

Glucose↗
PubMed2003

[Induction of hairy roots of Pueraria phaseoloides and its culture in liquid and solid medium].

An efficient transformation system for genetic transformation of medicinal plant, Pueraria phaseoloides, which contains puerarin and daidzein with hypothermic, spasmolytic, hypotensive and anti-arrhythmic activities, by using agropine-type Agrobacterium rhizogenes ATCC 15834 was developed. Hairy roots could be obtained directly from the cut edges of petioles of leaf explants of P. phaseoloides or via callus 20 days after inoculation with agrobacterium. The percentage of rooted leaf explants 35 days after infection was about 85%. Hairy roots could have a rapid growth on solid or liquid growth regulator-free MS medium. The transformation of hairy roots was confirmed by PCR amplification of rol B and rol C genes of Ri plasmid from A. rhizogenes. To investigate the physiological difference between solid and liquid culture, the biomass (fresh weight and dry weight), the reactive oxygen species (ROS) and the total content of soluble sugar in hairy roots cultured for 15 days in solid and liquid medium were detected, respectively, by the method of fluorescence labeling of 2',7'-dichlorofluorescein diacetate (2',7'-DCFH-DA) and by the anthrone colourimetry. Compared to hairy roots in solid medium, hairy roots grew more rapidly in liquid medium but formed no callus and appeared to become brown earlier during culture. The fresh weight, the dry weight, the total content of soluble sugar and the levels of reactive oxygen species of hairy roots cultured into liquid medium MS without plant growth regulators for 15 days were 1.59 times, 1.18 times, 5.25 times and 1.16 times, respectively as much as that of hairy roots cultured onto solid medium. Our results firstly indicate that P. phaseoloides hairy roots in solid medium can utilize or metabolize more soluble sugar but produce less reactive oxygen species than that in liquid medium. This may be related to the fact that hairy roots are easier to turn brown in liquid medium than that onto solid medium. Our results have laid a foundation for defining optimum culture manner for large-scale cultivation and large-scale production of secondary metabolites of P. phaseoloides hairy roots.

Culture Media↗
PubMed2006

[Relationship between hepatic insulin resistance and the expression of genes involved in hepatic glucose output].

OBJECTIVE: To study the relationship between hepatic insulin resistance induced by high fat diet and the expression of genes involving hepatic glucose output. METHODS: Normal 8-week-old male SD rats were randomly divided into two groups, i.e, normal chow group (NC, n = 10) and high fat diet group (HF, n = 10). They were fed for 28 weeks. Body weight and fasting blood glucose (FBG) were measured. At the end of the experiment, the rats were sacrificed and their fasting insulin (INS) and triglycerides (TG) were measured. Hepatic insulin sensitivity was measured by tissue uptake of 3H-2-deoxyglucose and the content of hepatic glycogen was measured using the anthrone method. Gene expression was investigated by using the semi-quantitative RT-PCR method. RESULTS: As compared with NC group, CF group rats developed visceral obesity which was accompanied by higher plasma TG. FBG in CF group increased starting from the 18th week (NC 4.77+/-63 mmol/L vs HF 5.45+/-87 mmol/L, P < 0.05). The rate of uptake of 3H-2-deoxyglucose in livers decreased by 51% in the HF group. The content of hepatic glycogen increased by 92.4% (P < 0.01). The level of phosphoenolpyruvate carboxykinase (PEPCK) and PGC-1a mRNA increased by 41.5% and 30.8%, respectively (P < 0.05). CONCLUSION: A high fat diet induced expressions of PGC-1a and PEPCK. It suggests that gluconeogenesis may play a role in the increase of hepatic glucose output and FBG.

Animals↗
PubMed2005

Cariogenic virulence characteristics of mutans streptococci isolated from caries-active and caries-free adults.

The objective of the study was to compare aciduricity (ability, to live in acid), acidogenicity (ability to produce acid), and intracellular polysaccharide production of mutans streptococci (MS) strains isolated from caries-active (CA, with one or more cavitated lesions) and caries-free (CF, with no clinically observable new caries in the last five years) adults. Forty-three MS strains from 17 of 17 CA adults, and 14 strains from eight of 12 CF adults were investigated. MS isolates' growth, survival, and pH reduction in pH 3.5-7.0 broths were evaluated to compare their acidogenicity and aciduricity. Extracellular water-soluble polysaccharide (WSP) and water-insoluble polysaccharide (WISP) was extracted from MS culture in BHI broth with 5 percent sucrose and assessed by a colorimetric anthrone-sulfuric acid microassay. No significant differences in mean aciduricity were found between CA and CF MS isolates (P>0.05, t test). However, significantly more CA subjects (29 percent) were colonized by MS strains with aciduricity above the average than CF subjects (13 percent, Fisher's exact test, P<0.05). Furthermore, CA MS strains produced significantly more acid at pH<5 (Mann-Whitney, P<0.05) and significantly more CA subjects were colonized with more acidogenic MS at pH<4.5 (Fisher's exact test, P<0.01). Similarly, CA MS isolates produced significantly more WISP than CF (Mann-Whitney test, P<0.01) while no statistical difference was found in WSP between the two groups. More CA subjects were colonized by multiple strains with aciduricity, acidogenicity, and polysaccharide synthesis ability above average. The study indicated that differences in acidogenicity, aciduricity, and polysaccharide synthesis in strains of MS may partially contribute to increased caries activity.

Acids↗
PubMed2006

[Trehalose loading red blood cells and freeze-drying preservation].

This study was aimed to investigate the feasibility of cryopreserving red blood cells (RBCs) by loading with trehalose and to evaluate the effect of trehalose on lyophilized RBCs. Based on the thermal properties of RBC plasma membrane, the RBCs were incubated in 0.8 mol/L trehalose solution at 37 degrees C for 7 hours, and RBCs incubated in phosphate-buffered saline were used as control. The morphology of RBCs was observed by light and scanning electron microscopy, the hemolysis rate of loaded RBCs was detected by using cyanohemoglobin kit, the intracellular trehalose levels were assayed by sulfate anthrone method, the intracellular ATP and 2, 3-DPG levels were determined by bioluminescence assay and 2, 3-DPG kit respectively, meanwhile the deformation and osmotic fragility of RBCs were measured. The results showed that the intracellular trehalose concentration was 36.56 +/- 7.95 mmol/L, the electronical microscopic images of trehalose-loaded RBCs showed the membrane integrity, the hemolysis rate in trehalose-loaded RBCs was 15.663 +/- 3.848%, while hemolysis rate in controlled RBC was 5.03 +/- 1.85% (P < 0.05). Maximum index of deformation in trehalose-loaded RBC was 0.0289 +/- 0.00738, while maximum index of deformation in control group was 0.1200 +/- 0.0121 (P < 0.05), The level of ATP in trehalose-loaded RBC was 2.67 +/- 0.54 micromol/gHb, while the level of ATP in control group was 5.22 +/- 1.10 micromol/gHb (P > 0.05). Osmotic fragility data showed that trehalose exerted osmotic protection on RBC. During loading period the level of 2, 3-DPG in trehalose-loaded RBC was maintained close to the level in control. When trehalose-loaded RBCs were lyophilized and rehydrated, the recovery rate of hemoglobin was about 46.44 +/- 4.14% and that in control was 8.33 +/- 2.34% (P < 0.001). The recovery rate of hemoglobin of trehalose-loaded RBC was higher than that of control. It is concluded that trehalose can be integrated in the membrane of RBC in lyophilization state, maintain the integrity of RBC membrane, and significantly enhance the recovery rate of hemoglobin of cryopreserved RBCs. Cryopreserving RBCs by loading with trehalose is feasible.

Blood Preservation↗
PubMed2006

[Purification and identification of a glycoprotein elicitor (CSBI) from Magnaporthe grisea].

A glycoprotein elicitor, CSBI, isolated from hyphal cell walls of the strain 97-151a of M. grisea race ZC(13) was purified by centrifugation, ultra-filtration, gel filtration and anion exchange chromatography (Fig.1). CSBI appeared as a single band on silver-stained SDS-PAGE (Fig.2). Anthrone-colorimetric assay and Coomassie blue G-250 staining showed that the carbohydrate-to-protein ratio was 9.32 (Table 1). The induction of peroxidase activity in incompatible interactions was stronger than in compatible interactions (P<0.05) after treatment with CSBI on rice leaves (Fig.3). The N-terminal sequence of CSBI was determined to be ITPEAMLSANCCSD, which showed high homology to a 78.671-kD hypothetical protein MG07877.4 (accession No. gi38107424) from M. grisea in NCBI databases. CSBI was either identified as hypothetical protein MG07877.4 by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS) with 9 matching peptides (Fig.4, Table 2).

Cell Wall↗
PubMed1991

The influence of some anthracene and diphenylmethane derivatives on water and electrolyte movement in rat colon.

The secretagogue activity of 30 different anthracene and diphenylmethane derivatives was investigated by determining their influence on water, sodium and potassium absorption in the gastrointestinal tract of the rat by direct administration into the rat colon. To obtain an effect two phenolic groups are necessary. However the distance between these groups seems to be a major factor for secretagogue activity. In the case of the anthranoids an intact anthraquinone or anthrone structure is a prerequisite.

Animals↗
PubMed1991

[An analysis of chemical oxygen demand, carbohydrate, IgG and IgA in extracellular fluid of bacterial plaque].

The chemical oxygen demand (COD) of extracellular plaque fluid was measured by potassium dichromate method. Micro-anthrone method and high performance liquid chromatography were used for measuring the carbohydrate content in the fluid. Immunochemistry system was used for measuring IgG and IgA contents in it. The results showed: (1) a high value of COD was found in the extracellular fluid, and it further increased with sugar-intake; (2) during resting stage, the content of carbohydrate measured by microanthrone method or high performance chromatography was very low, and there was no free glucose, fructose or sucrose; (3) no difference of IgG and IgA contents in plaque fluid between caries active (CA) and caries free (CF) subjects was found.

Adolescent↗
PubMed1991

Sugars in sandflies.

The evidence for the acquisition of different types of sugars by wild caught sandflies is reviewed and the recent results summarised. Studies on Phlebotomus ariasi, P. perfiliewi and P. perniciosus in the Mediterranean region has shown that these sandflies take honeydew derived sugars from aphids or coccids; in a similar study in the New World, Lutzomyia peruensis has also been shown to have taken sugar from such sources. The use of High Performance Liquid Chromatography (HPLC) as a technique for identification of such sugars is used as a more sensitive method for identifying trisaccharides and disaccharides; this method should supersede the van Handel cold anthrone test for sugar identification which only identifies the presence of fructose moieties. The possible significance of sugar feeding in the biology of sandflies and for the transmission of Leishmania are discussed.

Animals↗
PubMed1991

Surgical indication and significance of portal vein resection in biliary and pancreatic cancer.

Tumor and vascular resection was carried out in 27 patients with biliary and pancreatic cancer. Vascular resection included resection and reconstruction of the both the portal vein and hepatic artery in two of the patients. Portal vein resection only was carried out in 23 patients, and resection of the side wall and plasty of the portal vein was carried out in the other two patients. The technical limit of portal vein resection without graft was 4 cm in the hepatic hilus and 7 cm after total pancreatectomy or pancreatoduodenectomy without grafts. On temporary occlusion of the portal vein between resection and reconstruction, simple occlusion was sufficient if it occurred within 30 minutes. In occlusion of more than 30 minutes, simultaneous occlusion of the superior mesenteric artery is better to prevent congestion of the intestine. If occlusion of more than 60 minutes is anticipated, a bypass between the superior mesenteric vein and the femoral vein with Anthron tube is recommended. The postoperative course was uneventful in 20 of the 27 patients. Two patients died within 1 month after surgery. The mortality rate for this aggressive surgery was 8.4%. Minor complications such as hydrothorax, small bile leakage, and localized abscess were observed but soon subsided in five patients. Fourteen of 27 patients survived or are alive after more than 1 year, and 9 of 14 patients survived or are alive after 2 years. Forty-seven percent of the patients who had no lymph node metastasis or peritumor lymph node metastasis without cancerous invasion of the portal vein intima survived more than 2 years. The longest length of survival of a patient with nonfunctioning islet cell carcinoma of the pancreatic head was 5 years 9 months. The longest surviving patient with ductal cell carcinoma of the pancreas is still living after 4 years. This approach is recommended in certain patients with vascular involvement but without lymph node metastasis or those patients with only peritumor lymph node involvement. Frozen section of mesenteric and paraaortic nodes should be standard practice before this aggressive resection.

Adult↗
PubMed1991

Evidence for a common genetic pathway controlling susceptibility to mouse skin tumor promotion by diverse classes of promoting agents.

The present study has compared different mouse stocks and strains with known sensitivity to phorbol ester skin tumor promotion for their sensitivities to skin tumor promotion by a prototypic organic peroxide (benzoyl peroxide, BzPo) and anthrone (chrysarobin, Chr) tumor promoter. Following initiation with either 7,12-dimethylbenz(a)anthracene and/or N-methyl-N'-nitro-N-nitrosoguanidine, groups of mice were promoted with several different doses of each promoting agent. Among mice selectively bred for sensitivity to phorbol ester promotion, the order of sensitivity to BzPo was inbred SENCAR (SSIn) greater than SENCAR greater than CD-1. With Chr as the promoter, the order of sensitivity was SENCAR greater than SSIn greater than CD-1. Concurrent tumor promotion experiments examined the responsiveness of two common inbred mouse strains, DBA/2 and C57BL/6. The phorbol ester-responsive mouse strain, DBA/2, was more sensitive to skin tumor promotion by Chr than was C57BL/6 at all doses tested but was clearly less sensitive than both SENCAR and SSIn mice. Finally, DBA/2 and C57BL/6 mice were similar in their responsiveness to BzPo promotion, but again both of these inbred strains were significantly less sensitive than were SSIn and SENCAR mice to this organic peroxide type of skin tumor promoter. Histological evaluations comparing SENCAR and C57BL/6 mice revealed that a major difference between these strains in response to multiple Chr and BzPo treatments was in the inflammatory response (measured by edema formation). Unlike 12-O-tetradecanoylphorbol-13-acetate, Chr and BzPo did not induce dramatic differences in the epidermal hyperplasia (as measured by epidermal thickness) in these two mouse lines. The results presented in this paper suggest that there is a common pathway controlling susceptibility to skin tumor promotion by 12-O-tetradecanoylphorbol-13-acetate, BzPo, and chrysarobin. These results are discussed in terms of a possible genetic model(s) for skin tumor promotion in mice.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1990

[A hybrid artificial liver system composed of primary cultured canine hepatocytes].

The usefulness of newly device hybrid artificial liver system was evaluated in anhepatic dogs. The artificial liver module was composed of 60 to 80gm. primary cultured canine (Beagle) hepatocytes which were attached to 200 borocillicate glass plates. Total hepatectomy were done through cavo-caval and porto-caval shunt method using Anthron catheter to 14 dogs. Dogs were divided into following three groups. Group I; no treatment (n = 6) Group II; plasma perfusion (n = 4) Group III; treated with the artificial liver systems (n = 4) The survival times were 21.3 +/- 5.6, 27.8 +/- 4.0, and 55.0 +/- 11.3 hours in group I, II, and III, respectively. The longest survival time was 65 hours in one of group III dogs. APTT levels in group I and II increased more than 100 sec. within 24 hours. On the other hand it was maintained within 50 sec. during 54 hours treatment in group III. Ammonia levels in group I and II extremely increased over 2000ng/dl. In group III, it was less than 400ng/dl for 54 hours. Plasma amino acid levels in group I and II (Glutamine, Arginine, AAA) revealed significantly higher than in group III at 18 hours after operation. It is concluded that the newly device hybrid artificial liver system was useful for in vivo liver support.

Amino Acids↗
PubMed1990

[Systemic hemodynamics and oxygen transport and consumption during the anhepatic phase of orthotopic liver transplantation in dogs].

During the anhepatic phase of orthotopic liver transplantation, the veno-venous bypass has been used to keep systemic hemodynamics (SHD) in a stable condition. In this study, changes of SHD and oxygen transport and consumption (OTC) during the anhepatic phase used the passive bypass (PB) with Anthron bypass tubes were compared with those used the pump-driven bypass (PDB) with a centrifugal pump in mongrel dogs. Moreover the effects of the increased instillation rate and administration of dobutamine on SHD and OTC were evaluated. The portal venous and inferior vena caval pressure were increased in PB group, but not in PDB group. Whenever PB or PDB was used, cardiac index and oxygen consumption were markedly decreased caused by hypovolemia. In PDB group trebled the instillation rate, SHD and oxygen consumption were not improved. These results suggested that the primarily cardiovascular depression during the anhepatic phase was related to the disturbance of SHD. When dobutamine was administered and the instillation rate was trebled in PDB group, SHD and OTC were maintained in a favorable state. It is concluded that PDB, administration of dobutamine and sufficient instillation are advantageous to maintain systemic hemodynamic stability during the anhepatic phase of orthotopic liver transplantation.

Animals↗
PubMed1989

Characterization of the hydroperoxide response observed in mouse skin treated with tumor promoters in vivo.

The production of hydroperoxides is rapidly increased and remains at 200-280% of the control 1-24 h after the second daily application of 17 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA) to mouse skin in vivo. The levels of hydroperoxides are increased 1.63-, 2.64-, 4.07-, and 4.31-fold 18 h after one, two, three, or four applications of TPA at 24-h intervals, respectively. The hydroperoxide response to TPA observed in whole skin reflects almost entirely the increased hydroperoxide-producing activity of the epidermis. Such hydroperoxide responses are triggered to various degrees by the anthrone derivatives and the phorbol esters and diterpene with complete and/or stage 2 tumor-promoting activities but not by the agents with only inflammatory, hyperplastic or stage 1 tumor-promoting activities. However, the Ca2+ ionophores A23187 and ionomycin are potent inducers of hydroperoxide formation. Several discrepancies are observed between the hydroperoxide response to TPA and the known effects of the tumor promoter on ornithine decarboxylase (ODC) induction. In contrast to the refractory state against ODC induction caused by TPA treatments repeated at intervals of less than 48 h, the time interval required for recovery of the hydroperoxide response to TPA in TPA-pretreated skins is only 5 h. The stimulatory effects of A23187, ionomycin and various diacylglycerols (DAGs) on hydroperoxide production do not correlate with their ODC-inducing activities. The increasing susceptibilities of C57BL/6, CF-1, and SEN-CAR mice to skin tumor promotion correlate with their hydroperoxide responses but not with their ODC responses to TPA. alpha-Difluoromethylornithine (DFMO) and other inhibitors of TPA-induced ODC activity fail to alter hydroperoxide production whereas the compounds that inhibit the hydroperoxide response to TPA, such as fluocinolone acetonide, have no or only minimal inhibitory activity against ODC induction. This would suggest that the hydroperoxide response to TPA does not require ODC induction and may not be essential for ODC induction. The hydroperoxide response to TPA is mimicked, but to a lesser degree, by the activator of protein kinase C, 1,2-dioctanoyl-sn-glycerol, and inhibited by verapamil, trifluoperazine, and palmitoylcarnitine. Populations of TPA-treated keratinocytes, therefore, may be responsible not only for ODC activation but also for hydroperoxide production. However, these two responses, which involve, at least in part, Ca2+ mobilization and protein kinase C activation and play important roles in the mechanism of skin tumor promotion, do not appear to be correlated.

Animals↗
PubMed1989

[The effect of porto-intrahepatic portal bypass on the ischemic liver during clamping the hepatic inflow].

The object of this study was to determine the critical bypass flow rate of the porto-intrahepatic portal bypass during clamping the hepatic inflow, and to clarify the pathophysiology caused by this bypass procedure with special emphasis on the hepatic injury. Porto-intrahepatic portal bypass was instituted, using anti-thrombogenic catheter (Anthron), during clamping the hepatic inflow in anesthetized dogs. Bypass flow rate (BFR) was controlled at 10%, 30% and 60% of the portal flow in the individual experimental groups. As the control study, double bypass (portosystemic and femoral arterio-intrahepatic portal bypass) or portal-systemic bypass was instituted during clamping the hepatic inflow, and porto-systemic bypass at 10% and 60% during clamping the portal vein. Total adenine nucleotide (TAN) and adenylate energy charge (EC) of the liver did not change during 2 hour clamp of the portal vein. Clamping the hepatic inflow, unless congested splanchnic circulation, demonstrated the same level as 30% porto-portal bypass. Taking changes in hemodynamics, portal into consideration and arterial pH and PO2 levels, serum transaminase levels, ICG retention rate and animal survival rate, we conclude that insufficient flow rate of porto-portal bypass (10%, 30%) even cause more severe hepatic damage, and critical flow rate must be between 30% and 60% during 1 hour clamp.

Adenine Nucleotides↗
PubMed1986

Free radicals in skin exposed to dithranol and its derivatives.

The generation of persistent free radical species derived from antipsoriatic drugs in their target tissue under use conditions is reported. Dithranol (anthralin, 1,8-dihydroxy-9-anthrone) and chemical analogues were applied topically to the ear of the pig and the time course of the production of the resulting free radicals was followed by electron spin resonance spectroscopy in biopsy samples. The spectral characteristics observed correspond to data previously reported in vitro for the anthralin-10-yl radical. The role of these radical species in the mode of action of the drug is discussed.

Animals↗
PubMed1988

Tumor progression in Sencar mouse skin as a function of initiator dose and promoter dose, duration, and type.

The influence of initiator dose and promoter dose, duration, and type on the progression of papillomas to carcinomas was examined in Sencar mice. A good dose-response relationship for promotion of papilloma formation by 12-O-tetradecanoylphorbol-13-acetate (TPA) [following initiation with 6.5 micrograms of 7,12-dimethylbenz(a)anthracene (DMBA)] was observed in the range of 0.125 to 2.0 micrograms/mouse. A maximal papilloma response was induced with 2 micrograms/mouse (24 papillomas/mouse). When adjusted for mortality, the carcinoma incidence after 60 wk of promotion was essentially the same (approximately 80%) for doses above 0.5 micrograms/mouse. In a related experiment, mice were given an initiation dose of either 2 or 20 micrograms of DMBA followed by applications of 2 micrograms of TPA for 3, 5, 7, or 60 wk. Papilloma formation was proportional to length of treatment, with a maximum of 29 papillomas/mouse (20-micrograms initiating dose of DMBA) and 10 papillomas/mouse (2-micrograms initiating dose of DMBA) occurring between 10 and 15 wk of promotion. In this experiment, the carcinoma incidence was clearly proportional to the duration of promoter treatment at the low initiation dose of DMBA. The carcinoma incidence, on the other hand, was similar (approximately 70%) in groups of mice given an initiation dose of 20 micrograms of DMBA and promotion treatment for greater than or equal to 5 wk. Thus, the initiator dose had a dramatic effect on the outcome of these experiments. Additional experiments were performed to compare tumor progression with the anthrone promoter, chrysarobin. At optimal promoting doses, chrysarobin treatment produced a maximum number of papillomas that was approximately 1/3 that produced by TPA (6.4 versus 17.0 papillomas per mouse, respectively). However, the carcinoma response was very similar in these two treatment groups, confirming previous work from this laboratory. In addition, chrysarobin treatment following 10 wk of TPA promotion did not enhance the progression of preexisting papillomas to carcinomas. The data presented in this paper are consistent with a model in which several types or stages of papillomas are initially produced during two-stage carcinogenesis in mouse skin with different probabilities of progressing to carcinomas. However, the data indicate that optimal doses of promoter and initiator exist and can influence interpretation of tumor progression studies in mouse skin.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1988

Alterations in epidermal polyamine levels and DNA synthesis following topical treatment with chrysarobin in SENCAR mice.

A single topical application of chrysarobin (220 nmol) to SENCAR mouse skin produced alterations in epidermal polyamine levels distinctly different from that following a single topical treatment with 3.4 nmol of 12-O-tetradecanoylphorbol-13-acetate (TPA). Putrescine and spermidine levels were elevated prior to the induction of epidermal ornithine decarboxylase. In this regard, putrescine levels were elevated at 6 and 24 h after a single application of chrysarobin. In addition, putrescine levels were elevated with a second major peak at 64 h after chrysarobin which coincided with elevated epidermal ornithine decarboxylase activity. Spermidine levels were substantially elevated from 24 to 96 h (peak at 60 h) after a single treatment. TPA treatment produced peak elevations in epidermal putrescine levels at 6 h and epidermal spermidine levels at 24 h after a single treatment. Epidermal spermine levels were dramatically depressed following treatment with chrysarobin (peak depression of approximately 60% below control at 24 h), but only slightly altered following treatment with TPA. The time courses for changes in epidermal DNA synthesis in mouse skin following single treatments with 3.4 nmol of TPA or 220 nmol of chrysarobin also showed considerable differences. TPA treatment produced several waves of DNA synthesis at approximately 18 and 48 h after treatment, while chrysarobin produced a single broad peak at 72 h after treatment. Treatment with chrysarobin was also associated with an initial, dramatic inhibition in epidermal DNA synthesis (to 23% of the control value) which was much more extensive than that elicited by TPA. Inhibition of epidermal DNA synthesis following treatment with chrysarobin was observed within a few hours after treatment and remained depressed until approximately 36 h after treatment. Following treatment with both chrysarobin and TPA, higher levels of epidermal DNA synthesis correlated closely with higher molar ratios of spermidine/spermine, indicating a strong relationship between epidermal spermidine levels and epidermal cell proliferation induced by both promoters. The data suggest that TPA and chrysarobin bring about initial changes in epidermal polyamines by distinct mechanisms; however, both compounds ultimately lead to a dramatic stimulation of epidermal DNA synthesis. These data further support our working hypothesis that anthrones promote skin tumors by an initial mechanism different from that of the phorbol esters.

Administration, Topical↗