Insulin-like growth factor I (IGF-I) and IGF binding proteins in seminal plasma before and after vasectomy in normal men.
OBJECTIVE
To examine the levels and origins of insulin-like growth factor I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) in the human male genital tract.


METHODS
Examining seminal plasma before and 3 months after vasectomy.


METHODS
Fifteen men who were candidates for vasectomy were included in the study.


METHODS
Seminal plasma and serum levels of IGF-I, IGFBP-1, and IGFBP-3 were determined by commercially available assays, furthermore, samples were subjected to Western ligand blotting.


RESULTS
Seminal plasma concentrations of IGF-I were significantly lower after vasectomy: 18.0 +/- 2.4 micrograms/L (before) and 12.5 +/- 1.2 micrograms/L (after). When the total ejaculate content of IGF-I was calculated, the figures were reduced by 50% after vasectomy: 45.64 +/- 7.8 ng (before) and 23.45 +/- 3.8 ng (after). The patterns observed for seminal plasma IGFBP-3 concentrations were 844.9 +/- 59 micrograms/L (before) and 816.5 +/- 65 micrograms/L (after). When the total ejaculate IGFBP-3 content was calculated there was a 36% reduction after vasectomy: 2,300 +/- 251 ng (before) and 1,474 +/- 217 ng (after).


CONCLUSIONS
A considerable amount of seminal plasma IGF-I and IGFBP-3 may be of testicular origin. Although the physiological significance of IGF-I and IGFBPs in the male reproductive system still remains uncertain, the demonstration of their presence in the testes add support to a functional role in the regulation of gonadal function.
Ovesen
P
P
Aarhus Kommunehospital, Denmark.
Flyvbjerg
A
A
Orskov
H
H
D000328:Adult; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism*; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018974:Insulin-Like Growth Factor Binding Protein 4; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009994:Osmolar Concentration; D011184:Postoperative Period; D012016:Reference Values; D012661:Semen / Q000378:metabolism*; D014659:Vasectomy
D002352:Carrier Proteins; D018970:Insulin-Like Growth Factor Binding Protein 1; D018971:Insulin-Like Growth Factor Binding Protein 2; D018974:Insulin-Like Growth Factor Binding Protein 4; D018969:Insulin-Like Growth Factor Binding Proteins; D007334:Insulin-Like Growth Factor I