alpha-N-acetylated beta-endorphin is differentially processed in the normal and hypothalamo-pituitary-disconnected (HPD) ewe.
We have used specific radioimmunoassay and high-performance liquid chromatography (HPLC) to determine content and molecular forms of pituitary alpha-N-acetylated endorphin (NacEP) in the intact and hypothalamo-pituitary-disconnected (HPD) sheep. No significant differences were seen in anterior pituitary (AP) immunoreactive (ir-) NacEP levels (control = 4.34 +/- 0.45 ng/mg; HPD = 4.38 +/- 0.83 ng/mg; n = 4) or in HPLC profiles following pituitary disconnection. In contrast, levels of ir-NacEP in the HPD intermediate lobe (IL) (263 +/- 16.5 ng/mg; n = 4) were double those in the control (110 +/- 14 ng/mg; n = 4), accompanied by a marked change in the molecular profile. In the control IL, the major species were Nac alpha EP (30%), Nac gamma EP (30%) and Nac beta EP1-27 (35%); in HPD IL, Nac beta EP1-27 (65%) is the dominant molecular form, with Nac alpha EP (11%) and Nac gamma EP (9%) relatively minor components.
Smith
A I
AI
Wallace
C A
CA
Autelitano
D J
DJ
Cheng
M C
MC
Clarke
I J
IJ
Funder
J W
JW
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000378:metabolism*; D005260:Female; D007031:Hypothalamus / Q000502:physiology*; D010902:Pituitary Gland / Q000378:metabolism / Q000502:physiology*; D010903:Pituitary Gland, Anterior / Q000378:metabolism; D011863:Radioimmunoassay; D012756:Sheep; D001615:beta-Endorphin / Q000031:analogs & derivatives*
D004723:Endorphins; D001615:beta-Endorphin; C035101:N-acetyl-beta-endorphin