Leukotrienes are a group of bioactive compounds which play important roles in immediate hyposensitivity reactions and
inflammation. Minami et al. (1987) reported the full-length cDNA and complete primary structure of human LTA4
hydrolase, an enzyme involved in the biosynthesis of eicosanoids.
General function
Enzyme, Oxidoreductase
Comment
Cellular localization
Cytoplasmic
Comment
Ovarian function
Comment
Expression regulated by
LH
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Ovarian localization
Granulosa, Theca, Luteal cells, Small luteal cells, Large luteal cells
Comment
Hattori N, et al 1998 reported that human large luteal cells in the menstrual cycle and early pregnancy express leukotriene A4 hydrolase.
Leukotriene (LT) A4 hydrolase (EC3.3.2.6) converts LTA4 to LTB4 which shows
a chemotactic activity to leukocytes. To investigate the involvement of LTB4 in
human corpus luteum (CL) function, the localization of LTA4 hydrolase in human ovarian tissues was examined by immunohistochemistry with a rabbit polyclonal
antibody against LTA4 hydrolase. The enzyme was weakly expressed on
granulosa cells of the follicles. After ovulation, the intensity of LTA4 hydrolase
on large luteal cells increased and was highest in the midluteal phase. High
expression was also observed in the CL of early pregnancy. In theca interna and
small luteal cells, LTA4 hydrolase was weakly detected in all developmental
stages. Immunoblot analysis demonstrated that the molecular mass of LTA4
hydrolase expressed in CL was 62 kDa, and confirmed that LTA4 hydrolase
expression increased during CL formation and remained high in early pregnancy.
The sequence encoding mRNA of LTA4 hydrolase, which was isolated from CL
and amplified by polymerase chain reaction, was shown to be identical to the
previously reported one. Immunocytochemistry showed that LTA4 hydrolase
expression in cultured granulosa cells increased over 4 days in vitro and was
enhanced by human chorionic gonadotrophin treatment. These expression profiles
of LTA4 hydrolase suggest the involvement of LTB4 in luteal cell function during
CL formation and early pregnancy.