Comparative study of the effects of different growth hormone doses on growth and spatial performance of hypophysectomized rats.
This study was designed to examine the effects of recombinant human growth hormone replacement on somatic growth and cognitive function in hypophysectomized (HYPOX) female Sprague-Dawley rats. Rats (5 per group) were randomized by weight to 3 experimental groups: group 1, administered 200 microg/kg of GH once daily for 9 days; group 2, administered 200 microg/kg of GH twice daily; and group 3, administered saline daily. Somatic growth was evaluated by measurement of body weight daily and of the width of the proximal tibial growth plate of the HYPOX rats. Cognitive function was evaluated using the Morris water maze (MWM) test. The results indicated that GH replacement therapy in HYPOX rats promoted an increase in the body weight and the width of the tibial growth plate in a dose-dependent manner. On the third day of the MWM test, the escape latency in the GH-treated groups 1 and 2 was significantly shorter than that in the control rats (P<0.001 and P=0.032, respectively), suggesting that rhGH improved spatial memory acquisition in the MWM test. Therefore it is concluded that rhGH replacement therapy in HYPOX rats stimulates an increase in somatic growth in a dose-dependent manner and also has beneficial effects on cognitive functions.
Kwak
Min Jung
MJ
Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Park
Hee-Ju
HJ
Nam
Mi Hyun
MH
Kwon
O Suk
OS
Park
So Young
SY
Lee
So Yeon
SY
Kim
Mi Jin
MJ
Kim
Su Jin
SJ
Paik
Kyung Hoon
KH
Jin
Dong-Kyu
DK
D000818:Animals; D001835:Body Weight; D005260:Female; D006128:Growth / Q000187:drug effects*; D006132:Growth Plate / Q000187:drug effects / Q000473:pathology; D019382:Human Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D007016:Hypophysectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D013037:Spatial Behavior / Q000187:drug effects*
D019382:Human Growth Hormone