Dynamics of exocytosis, endocytosis and recycling in single pituitary gonadotropes.
The dynamic changes in exocytosis, endocytosis and recycling in single gonadotropes induced by gonadotropin-releasing hormone (GnRH) were visualized and estimated with an impermeable fluorescent membrane probe, 1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatrien (TMA-DPH), using a digital imaging and confocal laser scanning microscope. 10(-7) M GnRH induced exocytosis and endocytosis within 10 sec and 60 sec, respectively. Recycling of the plasma membrane started at 180-300 sec. Exocytosis and endocytosis in purified gonadotropes changed dose-dependently with 10(-10)-10(-7) M GnRH. These results show that GnRH-induced exocytosis, endocytosis and recycling in gonadotropes maintain dynamic equivalence. The procedure we established will be very useful in studies of the function of secretory cells.
Masumoto
N
N
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Tasaka
K
K
Mizuki
J
J
Tahara
M
M
Miyake
A
A
Tanizawa
O
O
D000818:Animals; D002451:Cell Compartmentation; D002469:Cell Separation; D004161:Diphenylhexatriene / Q000031:analogs & derivatives / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology*; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005456:Fluorescent Dyes / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000494:pharmacology*; D007091:Image Processing, Computer-Assisted; D008566:Membranes / Q000378:metabolism; D008856:Microscopy, Fluorescence; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar
D005456:Fluorescent Dyes; D004161:Diphenylhexatriene; D007987:Gonadotropin-Releasing Hormone; C033628:1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene