Tetrahydrofuran: two-generation reproduction toxicity in Wistar rats by continuous administration in the drinking water

Insulin-elicited endothelin release in hypertriglyceridemic, hypertensive, hyperinsulinemic (HTG) rats was shown. Weanling male Wistar rats were given 30% sucrose in their drinking water for 20–24 wk. In vitro contractions of aorta and femoral arteries were elicited with 40 mM KCl. Endothelin release induced with KCl plus 50 μU/ml insulin resulted in increases in contractile responses: 41 ± 5.9 and 57 ± 6% for control and 65.5 ± 6 and 95 ± 9% for HTG aortas and femoral arteries, respectively. The endothelin ETB-receptor blocker BQ-788 decreased responses to KCl + insulin by 39 ± 8 and 53 ± 5% in control and 48 ± 13 and 79 ± 3.5% in HTG aortas and femoral arteries, respectively. The ETA-receptor antagonist PD-151242 inhibited these responses by 12 ± 10 and 1 ± 9% in control and by 51.5 ± 9 and 58.5 ± 1% in HTG aortas and femoral arteries, respectively. These results suggest that endothelin may contribute to the hypertension in this model.

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Toxic effects of Cr(VI) in liver after administration in the drinking water to Wistar rats

Toxicology Letters ◽

10.1016/j.toxlet.2006.07.077 ◽

2006 ◽

Vol 164 ◽

pp. S202

Author(s):

A. Rafael ◽

A. Almeida ◽

I. Parreira ◽

P. Santos ◽

M. Carvalho ◽

...

Keyword(s):

Drinking Water ◽

Wistar Rats ◽

Toxic Effects

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Determination of the L-ascorbic acid requirements in Wistar osteogenic disorder Shionogi rats for prolonged carcinogenesis experiments

Laboratory Animals ◽

10.1258/002367796780739826 ◽

1996 ◽

Vol 30 (4) ◽

pp. 337-346 ◽

Cited By ~ 10

Author(s):

S. W. Y. Chan ◽

P. C. Reade

Keyword(s):

Animal Model ◽

Ascorbic Acid ◽

Drinking Water ◽

Normal Level ◽

Physical Condition ◽

Wistar Rats ◽

Clinical Signs ◽

Supplement Group ◽

Palatal Mucosa

Wistar Shionogi rats of the ( od/od) substrain with the osteogenic disorder are unable to synthesize L-ascorbic acid ( L-AA) and appear to be an appropriate animal model for studying the effect of L-AA in carcinogenesis. To determine the minimal L-AA requirements of these animals for prolonged survival in a satisfactory physical condition during experimentation, four concentrations of L-AA (0.33 g/l, 0.67 g/l, 1.67 g/l and 3.33 g/l) were administered via drinking water to four groups of animals ( n=2). Their water intake per cage was recorded three times weekly and the plasma L-AA levels were determined at the start, after 2, 4, 8 and 12 weeks and at the termination of the experiment. To simulate the procedures to be undertaken in oral mucosal carcinogenesis experiments, the animals were gently restrained and a designated amount of sterile NaCl was applied to the palatal mucosa three times a week for 26 weeks. The L-AA supplement group with the lowest concentration (0.33 g/l L-AA) achieved mean plasma levels of 7 ± 1.38 μM, approximately one-eighth that of the normal level (mean plasma L-AA level in outbred Wistar rats was found to be 58 ± 3 μM) whilst those in the higher supplement group (3.33 g/l L-AA) achieved a mean of 18 ± 1.25 μM. All of the animals employed in the present study survived for 26 weeks and showed no clinical signs of L-AA deficiency during this period.

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Transplacental Toxicity and Carcinogenesis Studies in Rats with Hexamethylenetetramine

Tumori Journal ◽

10.1177/030089167005600602 ◽

1970 ◽

Vol 56 (6) ◽

pp. 325-334 ◽

Cited By ~ 16

Author(s):

Giuseppe Della Porta ◽

José R. Cabral ◽

Giorgio Parmiani

Keyword(s):

Drinking Water ◽

Body Weight ◽

Wistar Rats ◽

The Body ◽

Carcinogenic Activity ◽

Long Term Experiments ◽

Pregnancy And Lactation ◽

Successive Generations ◽

And Control

In a previous paper (Fd Cosmet. Toxicol., 6: 707–715, 1968) it was reported that hexamethylenetetramine (HMT) had no carcinogenic activity in long-term experiments in mice and rats. In the present study, 12 ♀ and 6 ♂ Wistar rats were given 1% HMT in the drinking water starting 2 weeks before mating. The females were kept under treatment during pregnancy and lactation. A similar untreated group of 12 ♀ and 6 ♂ served as control. Twelve treated females and eleven controls became pregnant and gave birth to 124 and 118 babies respectively; no malformations were noted. From these animals, 24 for each sex were continued on the 1% HMT up to the 20th week of age or were kept untreated. The body weight of treated animals was significantly lower than that of controls one, only up to the 9th week of age for the males and up to the 13th week for the females. At the end of the treatment both groups were sacrificed; the weight of organs was identical in the treated and control animals; there were no gross or histological pathology. In a second experiment, rats were given 1% HMT in the drinking water for 3 successive generations, up to the age of 40 weeks in the F1 and F2 groups and of 20 weeks for F3. The three groups were composed of 13 ♂ and 7 ♀, 15 ♂ and 11 ♀, 12 ♂ and 12 ♂, respectively. In addition, a group of 16 ♂ and 16 ♀ descendants of 2% HMT treated parents, were given 2% HMT for 50 weeks. A group of 48 ♂ and 48 ♀ served as untreated controls. All groups were kept under observation for over 2 years of age. No evidence of carcinogenicity was found in any of the HMT-treated groups.

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Gingival Changes in Wistar Rats after Oral Treatment with 4-Nitroquinoline 1-Oxide

European Journal of Dentistry ◽

10.1055/s-0039-1698331 ◽

2007 ◽

Vol 01 (03) ◽

pp. 152-157 ◽

Cited By ~ 11

Author(s):

Daniel Araki Ribeiro ◽

Daisy Maria Fávero Salvadori

Keyword(s):

Squamous Cell Carcinoma ◽

Drinking Water ◽

Cell Carcinoma ◽

Squamous Cell ◽

Wistar Rats ◽

Oral Treatment ◽

Test System ◽

Gingival Tissue ◽

Cancer Pathogenesis ◽

Rat Tongue

ABSTRACTObjectives:4-nitroquinoline 1-oxide (4NQO)-induced rat tongue carcinogenesis is a useful model for studying oral squamous cell carcinoma. However, gingival changes following 4NQO administration via drinking water are absent in the literature. The aim of this study was to investigate gingival changes concomitant to tongue carcinogenesis induced by 4NQO by means of morphological analysis.Methods:Male Wistar rats were distributed into 3 groups of 10 animals each and treated with 50 ppm 4NQO solution by drinking water for 4, 12 or 20 weeks. Thirty animals were used as negative control.Results: Regarding tongue mucosa, the primary histopathological change i.e., hyperplasia and dysplasia was evidenced after 12 weeks treatment with 4NQO. At 20 weeks, squamous cell carcinoma was found in the majority of animals. Gingival squamous hyperplasia was induced by 4NQO after 20-weeks of treatment. Dysplastic changes appeared in some animals (two cases) as well.Conclusions:Taken together, our results support the notion that 4NQO is more effective in rat tongue mucosa than gingival tissue. Probably, this discrepancy depends strongly on route of administration and the susceptibility with respect to animals species. Certainly, such data will contribute when using this experimental test-system for understanding oral cancer pathogenesis. (Eur J Dent 2007;1:152-157)

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