Colocalized peptides in gonadotrophs: LeuEnkephalin and ACTH interact differently on GnRH induced LH and FSH release.
Two peptides that have been previously colocalized in the gonadotrops (LeuEnkephalin with LH and ACTH with FSH) can stimulate the release of gonadotropins in primary culture of anterior pituitary cells. In presence of both substances, and in contrast to LHRH induced secretion, the augmentation of LH release is never dose dependent. It is always significantly higher than controls, for high (10(-6) M) or low concentrations (10(-12) M). Prolactin release is only modified in presence of Leu-Enkephalin. Met-Enkephalin does not increase the liberation of LH, FSH, or Prolactin in vitro. Furthermore, while Leu-Enkephalin can enhance the stimulating effect of LHRH, ACTH has a negative interaction with LHRH, when these two peptides are added together in incubation medium. These results demonstrate that Leu-Enkephalin and ACTH can in vitro modulate the release of gonadotrophins at the pituitary level suggesting a physiological role for such colocalization.
Slama
A
A
INSERM U 159, Centre Paul Broca, Paris, France.
Burg-Poveda
D
D
Tramu
G
G
D000324:Adrenocorticotropic Hormone / Q000032:analysis / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D004743:Enkephalin, Leucine / Q000032:analysis / Q000502:physiology*; D004744:Enkephalin, Methionine / Q000502:physiology; D005640:Follicle Stimulating Hormone / Q000032:analysis / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000502:physiology; D007700:Kinetics; D007986:Luteinizing Hormone / Q000032:analysis / Q000378:metabolism*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000737:chemistry / Q000166:cytology / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D007987:Gonadotropin-Releasing Hormone; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; D000324:Adrenocorticotropic Hormone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone