Gonadotropin depression of adenosine triphosphate levels and interaction with adenosine in rat granulosa cells.
Endocrinology
; 118(2): 645-52, 1986 Feb.
Article
em En
| MEDLINE
| ID: mdl-3002759
ABSTRACT
Cellular ATP levels were measured with the luceferin-luciferase enzyme method in incubated preovulatory granulosa cells in vitro from PMSG-treated immature rats. The ATP levels were depressed by both FSH and LH, FSH being the more effective. Adenosine enhanced the ATP levels about 3-fold, but the depressive effects of gonadotropins could not be overcome by the addition of adenosine. Uptake of adenosine in granulosa cells followed Michaelis-Menten kinetics, with a Km of 15.9 +/- 3.6 microM and a maximum velocity of 1.6 +/- 0.1 pmol/min X 10(5) cells. The half-time for uptake of adenosine was about 40 min. The maximal uptake of adenosine was lowered from 48 +/- 5 to 30 +/- 1 pmol/10(5) cells by FSH treatment of the cells. The basal secretions of cAMP and progesterone from the granulosa cells were slightly but significantly enhanced by adenosine alone. Adenosine markedly enhanced FSH-stimulated cAMP secretion, but not progesterone secretion. A nonmetabolizable adenosine analog, 2-chloro-adenosine, did not affect the ATP levels or the secretion of cAMP from granulosa cells. This study confirms previous observations that adenosine can increase ATP levels and amplify the response to gonadotropins in gonadal cells. A novel finding is that the levels of ATP in granulosa cells are markedly depressed by gonadotropins. It is speculated that this depression of ATP may be a factor in the metabolic control of granulosa cells.
Buscar no Google
Base de dados:
MEDLINE
Assunto principal:
Hormônio Luteinizante
/
Adenosina
/
Trifosfato de Adenosina
/
Hormônio Foliculoestimulante
/
Células da Granulosa
Limite:
Animals
Idioma:
En
Revista:
Endocrinology
Ano de publicação:
1986
Tipo de documento:
Article