The effect of castration and androgen replacement on rat pituitary follicle stimulating hormone investigated by reversed-phase high performance liquid chromatography.
Rat follicle stimulating hormone (rFSH) was analysed in extracts of rat anterior pituitary using a newly developed separation method of reversed-phase high performance liquid chromatography (RP-HPLC) and post-column detection of immunoreactivity (rFSH-IR) by radioimmunoassay (RIA) or immunoprecipitation with a specific anti-rFSH antibody. Good separation of rFSH was achieved on a Waters Radial-Peak 8MBC18 cartridge with a linear (60 min) gradient from 10-60% acetonitrile at constant 0.1% trifluoroacetic acid concentration. The elution profiles of radioiodinated purified rFSH [(125I)rFSH] as well as extracts of adult male and female rat pituitaries contained two main immunoreactive components (peaks 1 and 2) which eluted at 16-17 min and 21 min respectively. In the (125I)rFSH elution profile, the peaks of immunobinding corresponded to two major peaks of radioactivity. The male pituitary showed greater binding to anti-rFSH-serum of peak 1 and 2 eluate compared to female pituitary. At day 20 after orchidectomy, the amount of immunoreactive rFSH (rFSH-IR) increased in both peaks (by 30% in peak 1 and 180% in peak 2); however, the rFSH-IR level in peak 2 appeared to be more variable compared with that in peak 1. Subcutaneous implantation of 5 mg or 15 mg of dihydrotestosterone (DHT) at the time of orchidectomy prevented the post-castration elevation of rFSH-IR at 10 and 20 days after surgery. The precise nature and physiological significance of the two elution peaks are not clear at this time; however, only peak 2 showed immunoreactivity with anti-rLH-alpha-subunit antibody (AFP 87713681) and the elution time of peak 2 coincided with that of (125I) rLH-alpha subunit (AFP-7264 B).(ABSTRACT TRUNCATED AT 250 WORDS)
D000728:Androgens / Q000494:pharmacology*; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D013196:Dihydrotestosterone / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000032:analysis*; D015292:Glycoprotein Hormones, alpha Subunit; D007106:Immune Sera; D008297:Male; D009919:Orchiectomy; D010446:Peptide Fragments / Q000032:analysis; D010903:Pituitary Gland, Anterior / Q000032:analysis*; D010908:Pituitary Hormones, Anterior / Q000032:analysis; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D000728:Androgens; D015292:Glycoprotein Hormones, alpha Subunit; D007106:Immune Sera; D010446:Peptide Fragments; D010908:Pituitary Hormones, Anterior; D013196:Dihydrotestosterone; D005640:Follicle Stimulating Hormone