Abstract: An object of the present invention is to provide a transgenic animal which is useful in a test for forecasting fetal toxicity and teratogenicity of drugs. The present invention provides a transgenic non-human animal or a part thereof wherein several foreign (human-type) proteins which are involved in the drug metabolism or mutant proteins thereof are expressed in the body; a recombinant gene which is useful for the production of said non-human animal; and a method for screening a substance having fetal toxicity and teratogenicity using said non-human animal.

Abstract: There are provided a method of determining a genotype of CYP2A6 gene on the basis of a difference in gene structures of a wild-type gene of CYP2A6 and at least one kind of mutant-type gene associated with mutation of CYP2A6 gene; the method mentioned above, wherein one kind of mutant-type gene associated with mutation of CYP2A6 gene is used, and the mutant-type gene is conversion-type CYP2A6 gene comprising the nucleotide sequence of SEQ ID NO: 4; the method mentioned above, wherein homozygous deletion and heterozygous deletion of CYP2A6 gene are determined by using at least two kinds of mutant-type genes associated with mutation of CYP2A6 gene; a method of determining a genotype of a CYP gene, characterized by carrying out a method comprising the method mentioned above to determine the genotype of the CYP gene; a diagnostic kit for determining a genotype of CYP2A6 gene, comprising 5′-primer capable of hybridizing to both exon 8 of CYP2A6 gene and exon 8 of CYP2A 7 gene, 3′-primer capable of speci

Abstract: A .beta.-glucuronidase inhibitor comprising at least one compound selected from the group consisting of baicalin, oroxylin A-7-O-glucuronide and luteolin-3'-glucuronide; an extract of scutellaria root (baikal skullcap; Scutellariae Radix) and/or schizonepeta spike (Japanese catnip; Schizonepelae Spica); or a Chinese and Japanese traditional prescription comprised of scutellaria root (baikal skullcap; Scutellariae Radix) and/or schizonepeta spike (Japanese catnip; Schizonepelae Spica) as a crude drug. The .beta.