IGF-I treatment increases motility and improves morphology of immature spermatozoa in the GH-deficient dwarf (dw/dw) rat.
It has recently been shown that short-term growth hormone (GH) treatment can increase the motility of spermatozoa in the GH-deficient dw/dw rat. To examine whether the effects of GH on motility of immature spermatozoa are mediated by an increase in plasma concentrations of IGF-I, we treated GH-deficient dw/dw rats with 2 microg/g/day of IGF-I using osmotic minipumps. Body weight (saline 227+/-5 g, IGF-I 253+/-4 g) and IGF-I concentrations in blood plasma (saline 472+/-19.9 ng/ml, IGF-I 986+/-43.6 ng/ml) and seminal vesicle fluid (saline 30.9+/-1.7 ng/ml, IGF-I 47.9+/-2.9 ng/ml) were significantly increased with IGF-I treatment (P<0.001), similar to the observed responses to GH therapy in our earlier study. While epididymal fluid IGF-I concentrations were not changed, IGF-I treatment significantly increased the number of immature motile spermatozoa (saline 14.4+/-3.5%, IGF-I 28.3+/-4.1%, P<0.05) and the number of spermatozoa with normal morphology (control 65.7+/-3.3%, IGF-I 75+/-1.9%, P<0.05). These data suggest that increasing the circulating concentrations of IGF-I in the GH-deficient rat can improve the motility and morphology of immature spermatozoa and thus mimic, at least in part, the effects of GH.
Vickers
M H
MH
Research Centre for Developmental Medicine and Biology, University of Auckland, Auckland, New Zealand.
Casey
P J
PJ
Champion
Z J
ZJ
Gravance
C G
CG
Breier
B H
BH
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004822:Epididymis / Q000187:drug effects / Q000378:metabolism; D013006:Growth Hormone / Q000172:deficiency*; D007334:Insulin-Like Growth Factor I / Q000378:metabolism / Q000494:pharmacology*; D007668:Kidney / Q000473:pathology; D008099:Liver / Q000473:pathology; D008297:Male; D009206:Myocardium / Q000473:pathology; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D011922:Rats, Mutant Strains; D012661:Semen / Q000187:drug effects / Q000378:metabolism; D013081:Sperm Motility / Q000187:drug effects*; D013094:Spermatozoa / Q000166:cytology / Q000187:drug effects*; D013154:Spleen / Q000473:pathology
D007334:Insulin-Like Growth Factor I; D013006:Growth Hormone