Long-term effects on bone of postnatal immunization against GHRH in female and male rats.
The effects of neonatal passive immunization against GHRH on bone was examined in male and female rats. Pups were treated subcutaneously with GHRH-antiserum (GHRH-Ab) from day 1 to day 10 of age. Bone mineral content (BMC) and bone mineral density (BMD) were evaluated at monthly intervals until 7 months. Markers of bone resorption (urinary lysylpyridinoline, LP), bone formation (serum osteocalcin, OC) and serum IGF-I were measured at 2, 3 and 7 months. In male rats, GHRH-Ab did not modify BMC and BMD when compared with controls. In contrast, female rats demonstrated lower whole body and femoral BMC and BMD from 2 to 7 months of age. Reduced bone growth in the females was associated with lower IGF-I levels than controls at 2 and 3 months of age, whereas in males IGF-I titers did not change during the period of the study. LP excretion was higher in GHRH-Ab-treated rats at 2 and 3 months in both sexes. In females, no difference in OC values was recorded, whereas in GHRH-Ab-treated males, there was an increase in OC levels at 2 and 3 months. These data indicate that transient GHRH deprivation induces an osteopenic effect in female rats which is not evident in male rats.
Sibilia
V
V
Department of Pharmacology, Chemotherapy and Medical Toxicology, Centre of Excellence of Neurodegenerative Diseases, University of Milan, Via Vanvitelli 32, Italy. Valeria.Sibilia@unimi.it
Rigamonti
A E
AE
Pagani
F
F
Lattuada
N
N
Guidobono
F
F
Wehrenberg
W B
WB
Muller
E E
EE
Netti
C
C
D000596:Amino Acids / Q000652:urine; D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers / Q000097:blood / Q000652:urine; D001835:Body Weight / Q000187:drug effects; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects; D001842:Bone and Bones / Q000378:metabolism / Q000502:physiology*; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000276:immunology / Q000502:physiology*; D007106:Immune Sera / Q000494:pharmacology; D007116:Immunization, Passive; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008297:Male; D008903:Minerals / Q000378:metabolism; D015675:Osteocalcin / Q000097:blood; D051381:Rats; D017207:Rats, Sprague-Dawley; D012723:Sex; D012741:Sexual Maturation / Q000187:drug effects
D000596:Amino Acids; D015415:Biomarkers; D007106:Immune Sera; D008903:Minerals; D015675:Osteocalcin; D007334:Insulin-Like Growth Factor I; C036020:deoxypyridinoline; D013007:Growth Hormone-Releasing Hormone