Plasma and pituitary concentrations of gonadotropins (FSH and LH) in minke whales (Balaenoptera acutorostrata) during the feeding season.
This study investigated plasma and pituitary concentrations of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) and steroid hormones (progesterone: P4, testosterone:T, estradiol-17beta: E2) by enzyme-immunoassay (EIA) in minke whales (Balaenoptera acutorostrata) captured during the feeding season (December to March) in the Antarctic Ocean. Plasma FSH and LH levels in female minke whales were higher (P <0.05) than in male whales. Although the pituitary weight was not significantly different between male and female whales, pituitary FSH and LH levels were higher in females than in males (P<0.01) and mature whales than immature whales (P<0.05). Plasma levels of FSH, T and E2 were not significantly different between immature and mature male whales, but plasma LH and pituitary FSH and LH levels were higher (P<0.05) in mature than in immature whales. In both immature and mature whales regardless of gender, pituitary FSH and LH levels were correlated significantly (r=0.69: P<0.01). In mature male whales, plasma T and E2 levels (r=0.60: P<0.01), and testis weight and plasma T levels (r=0.46: P <0.05) were correlated. In immature female whales, plasma FSH and LH levels were highly correlated (r=0.68: P<0.001), but were not for mature female whales. The results show that gender and maturity influence gonadal and pituitary function of minke whales during the feeding season.
Suzuki
T
T
Laboratory of Animal Genetics and Reproduction, Obihiro University of Agriculture and Veterinary Medicine, Japan.
Mogoe
T
T
Asada
M
M
Miyamoto
A
A
Tetsuka
M
M
Ishikawa
H
H
Ohsumi
S
S
Fukui
Y
Y
D000367:Age Factors; D000818:Animals; D000864:Antarctic Regions; D004958:Estradiol / Q000097:blood / Q000378:metabolism; D005247:Feeding Behavior / Q000502:physiology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D016014:Linear Models; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D008297:Male; D010902:Pituitary Gland / Q000737:chemistry / Q000378:metabolism*; D011247:Pregnancy; D011374:Progesterone / Q000097:blood / Q000378:metabolism; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D012737:Sex Factors; D013739:Testosterone / Q000097:blood / Q000378:metabolism; D014907:Whales / Q000097:blood / Q000378:metabolism* / Q000502:physiology
D013739:Testosterone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone