Expression of opioid genes in bovine seminal vesicles.
In seminal vesicles, the organ producing most of seminal plasma in the bovine species, the pro-opiomelanocortin and the proenkephalin genes are transcribed and translated, and their translation products processed into opioid peptides, which are secreted into the seminal plasma. By using a micro-organ preparation of seminal vesicles we found that, after 20 h of incubation with labelled methionine, a multiplicity of opioids was produced. Among these, [Met]enkephalin and beta-endorphin were positively identified, whereas in the newly formed secretion only [Met]enkephalin was detected. This may be correlated to the finding that the concentration of beta-endorphin in an extract of seminal plasma was one order of magnitude lower than that of [Leu]enkephalin and [Met]enkephalin. These findings expand the picture of the presence of opioid peptides in the male reproductive tract, indicating that they should have a role(s) in the physiology of reproduction, not only in the hypothalamus-pituitary-gonadal axis, determining the reproductive potential, but also in the so-termed sex accessory glands, determining the actual events leading to reproduction. To our knowledge this is also the first case studied of opioid peptides produced as exocrine hormones.
Piccoli
R
R
Dipartimento di Chimica Organica e Biologica, Università di Napoli, Italy.
Pasanisi
A
A
Carsana
A
A
Palmieri
M
M
D'Alessio
G
G
D000818:Animals; D002417:Cattle; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D004723:Endorphins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D008297:Male; D009693:Nucleic Acid Hybridization; D014176:Protein Biosynthesis; D012669:Seminal Vesicles / Q000378:metabolism*; D012997:Solvents; D014158:Transcription, Genetic
D004723:Endorphins; D012997:Solvents