Development of an Aquatic Bioassay for Carcinogenicity and Toxicity Testing Using the Medaka (Oryzias latipes) as a Model

1990 ◽  
Author(s):  
Tracie E. Bunton
Keyword(s):  
Toxicity Testing ◽  
Oryzias Latipes ◽  
Aquatic Bioassay

Toxicity Testing of Leachate from Waste Landfills Using Medaka (Oryzias Latipes) for Monitoring Environmental Safety

2006 ◽  
Vol 117 (1-3) ◽  
pp. 73-84 ◽  
Author(s):  
Kae Osaki ◽  
Shosaku Kashiwada ◽  
Norihisa Tatarazako ◽  
Yoshiro Ono
Keyword(s):  
Toxicity Testing ◽  
Oryzias Latipes ◽  
Environmental Safety

Use of the Japanese Medaka ( Oryzias latipes ) and Guppy ( Poecilia reticulata ) in Carcinogenesis Testing Under National Toxicology Program Protocols

2003 ◽  
Vol 31 (1) ◽  
pp. 88-91 ◽  
Author(s):  
William E. Hawkins ◽  
William W. Walker ◽  
John W. Fournie ◽  
C. Steve Manning ◽  
Rena M. Krol
Keyword(s):  
Poecilia Reticulata ◽  
Oryzias Latipes ◽  
Japanese Medaka ◽  
National Toxicology Program

SPECIAL PROBLEMS IN TOXICITY TESTING OF LONG ACTING DEPOT CONTRACEPTIVES

1974 ◽  
Vol 77 (1_Suppla) ◽  
pp. S315-S354 ◽  
Author(s):  
F. Neumann ◽  
R. von Berswordt-Wallrabe ◽  
W. Elger ◽  
K.-J. Gräf ◽  
S. H. Hasan ◽  
...  
Keyword(s):  
Biological Effects ◽  
Histological Finding ◽  
Toxicity Testing ◽  
Prolactin Secretion ◽  
List Type ◽  
Human Species ◽  
Prolactin Plasma Level ◽  
Human Use ◽  
Long Acting ◽  
Reproductive Processes

ABSTRACT Two types of so-called "depot contraceptives", long-acting steroids which are of interest for human use, were studied in animals. Norethisterone oenanthate, mainly gestagenic in the human and other species, turned out to be predominantly oestrogenic in rats. This oestrogenicity caused indirectly, via an enhanced hypophysial prolactin secretion, the well-known hypophysial and mammary tumours in rats. Another synthetic gestagen, 4,6-dichloro- 17- acetoxy- 16α-methyl-4,6-pregnadiene-3,20-dione, which might be considered in its biological actions similar to preparations containing chlormadinone acetate or medroxy-progesterone acetate, induced no signs of oestrogenicity in dogs. It is surmised that its gestagenic influence indirectly, and probaby, via an enhanced hypophysial prolactin secretion caused "mammary nodules" in this "non-rodent" species. These studies have born out mainly two facts: A synthetic steroid, norethisterone oenanthate, exerted different biological effects in different species: it was a gestagen in the rabbit, whereas in rats, its predominant influence was oestrogenic. The hypophysial prolactin secretion was enhanced in various species by different mechanisms: in rats, the oestrogenicity caused an increased prolactin plasma level, whereas in dogs, a gestagen with obviously no inherent oestrogenicity, 4,6-dichloro-17-acetoxy-16α-methyl-4,6-pregnadiene-3,20-dione, converted the histological appearance of the anterior pituitary into a condition with a greatly increased number of eosinophils. This histological finding was interpreted as an indicator for a hypersecretion of prolactin. Hence, animal work with "gestagens" has only limited predictive value with respect to their possible effects in the human species. Therefore, inflexible recommendations are not helpful in solving the safety problem of long-acting steroids which affect primarily reproductive processes.

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