Biological traits of rare males in the population of Carassius gibelio (Actinopterygii: Cyprinidae) from Lake Pamvotis (north-west Greece).

The gynogenetic population of Prussian carp Carassius gibelio in Lake Pamvotis (north-west Greece) included a small percentage of males (2-3%). Cytogenetic analysis revealed heterogeneity of the population at the ploidy level: all females were triploid (modal chromosome number 156-162 chromosomes) while the males were either triploid (modal number 156-158 chromosomes) or tetraploid (modal number 200-214 chromosomes). Morphometric analysis revealed significant differences in body shape among these three groups. The males were more slender than females, while the triploid males could be discriminated from the tetraploid by the morphology of their caudal peduncle. The males attained a significantly lower asymptotic standard length (L(S)) (25.04 cm) than females (29.75 cm) and had lower exponent b of the L(S) and mass relationship. Under laboratory conditions, intraspecific crossings of C. gibelio males with females could give viable all-female offspring; in comparison with goldfish Carassius auratus males, the fertility of the C. gibelio males was generally reduced but remained highly variable among individuals.

Beneficial effects of a vanadium complex with cysteine, administered at low doses on benzo(alpha)pyrene-induced leiomyosarcomas in Wistar rats.

BACKGROUND: Vanadium is a potent environmental and body metal, possessing remarkable antitumor and antidiabetic properties. Vanadium salts and complexes have been widely investigated for their anticarcinogenic properties in experimental carcinogenesis. In the present study the antitumor effects of a new vanadium complex with cysteine in relation to identical doses of vanadyl sulfate and cysteine, in tumor bearing rats are investigated. MATERIALS AND METHODS: Male wistar rats were injected with benzo(alpha)pyrene and divided into four groups of 21 rats each. Control group was treated only with BaP. The first group(TR-1) was treated by vanadyl sulfate per os at daily doses of 0.5 mg of V/kg b.w per day. The second (TR-2) by cysteine at doses of 4.5 mg/kg b.w per day and the third group (TR-3), by the complex V(III)-cysteine at daily doses of V 0.5 mg/kg b.w (containing cysteine at concentrations of 4.5 mg/b.w). Treatment was started when tumors were developed (evidenced from a palbable mass at the site of Bap injection) and went on till death. Toxicological tests were performed in 27 rats divided into a control group and two test groups; T-1 administered with vanadyl sulfate at daily doses of 18.5 mg V/kg b.w and T-2 group with V(III)-cysteine complex at daily doses of 18.5 V/kg b.w, for 9 weeks. Mean survival time, death rate, tumor growth rate, the carcinogenic potency of BaP, and the anticarcinogenic potency in relation to histological findings in each treatment group were calculated in each group in order to evaluate the antitumor effects of the substances used. RESULTS: Vanadyl sulfate, cysteine and V(III)-cysteine exerted antitumor effects on leiomyosarcoma bearing Wistar rats. However, V(III)-complex exerted much more potent effects than the other treatments, significantly prolonging mean survival time, retarding tumor growth rate and decreasing the carcinogenic potency of BaP in the TR-3 group, in comparison to the control and the TR-1 and TR-2 groups. Moreover V(III)-cysteine complex resulted in complete remission of 4 (19.7%) of the tumor bearing rats. Blood, urine, biochemical routine tests as well as autopsy did not reveal any toxic effects either of vanadyl sulafate or V(III)-cysteine complex. CONCLUSIONS: Vanadyl sulfate, cysteine and V(III)-cysteine complex exerted antitumor effects in tumor bearing rats. The V(III)-cysteine complex, however, exerts much more potent effects, as evident from the results of the present study. These beneficial effects of the above complex, in combination with its low toxicity provide evidence suggest its possible application in the treatment of human malignant diseases.

Dose-related preventive and therapeutic effects of antioxidants-anticarcinogens on experimentally induced malignant tumors in Wistar rats.

A combination of antioxidants-anticarcinogens, consisting of vitamins C and E, selenium and 2-mercaptopropionyl glycine (2-MPG), was administered orally for the prevention (PRG) and treatment (TRG) of benzo(a)pyrene (BaP)-induced malignant tumors (leiomyosarcomas), in Wistar rats. In order to evaluate dose-related effects, a low dose vitamin (0.15 g/kg b.w. per day of vit.C and 0.05 g/kg b.w. per day of vit.E) and a high dose (1.5 g/kg b.w. per day of vit.C and 0.5 g/kg b.w. per day of vit.E) combination was administered, in prevention and treatment groups. Selenium was administered in doses of 2 microg/kg b.w. per day and 2-MPG in 15 mg/kg b.w. per day, in all groups. Daily estimations of 24 h urine volume levels of thiobarbituric acid reacting substances (MDA) were performed in 20 animals, divided into a control group, a BaP-injected group, a tricapryline-injected group and a BaP-injected and treated by the low dose combination group. Results revealed that the low dose combination failed to exert any beneficial effect on mean survival time of animals treated either preventitively or therapeutically. An increased number of animals bearing a second (lung) tumor was, in addition, found in autopsy and histological examination in the low dose combination (PRG and TRG) and the high dose TRG groups. The high dose combination groups manifested a significant prolongation of the mean survival time of animals; complete remission of tumors developed in 16.8% of the animals in the treatment group and a 5.2% prevention of tumor formation in the preventive group, without any evidence of an increased number of double tumor formation in the PRG group. Urine MDA increased significantly in animals injected by BaP during the first 10 days and since the 90th day (formation of palpable tumors) after injection, in relation to control and tricapryline-injected groups. Complete prevention of urine MDA-increased values was obtained in BaP-injected and treated by the low dose combination animals. Results indicate that high doses (megadoses) of the antioxidant-anticarcinogen vitamins C and E in combination with carefully selected other antioxidants possessing supplementary actions, are probably needed in order to achieve a sufficient prevention and treatment of malignant diseases.

Comparison of the therapeutic effects of two vanadium complexes administered at low dose on benzo[a]pyrene-induced malignant tumors in rats.

The antitumor effects of low dose administration of the vanadium(III) complexes with L-cysteine (complex 1) and N-(2-mercaptopropionyl)-glycine (complex 2) were compared on benzo[a]pyrene (BaP)-induced tumors in Wistar rats. Male Wistar rats, injected with 10.0 mg of BaP, were divided into one control (C-G) and two treatment (TR-G) groups of 17 animals each. Animals of the first treatment group were administered complex 2 (TR-2 group) and those of the second group were administered complex 1 (TR-1 group) at doses of 100 microg of vanadium per os daily, starting from the day a palpable tumor was developed till their death. BaP injection induced a 100% tumor (leiomyosarcomas) development in the animals of all groups. Administration of complex 1 to the animals resulted in a significant prolongation of the mean survival time, a complete remission of 17.6% of the tumors developed, a significant reduction of the carcinogenic potency (CP) of BaP and of the tumor growth rate (TGR) in TR-1 group animals, compared to the control and the TR-2 group. In marked contrast, complex 2 failed at the doses administered to exert any significant modulation of the above mentioned parameters. Results indicate that at low (100 micro/day) concentrations of vanadium, complex 1 exerts a significant anticarcinogenic effect on experimentally-induced leiomyosarcomas in rats, whereas complex 2 has no effect when administered at the same low concentrations of vanadium.