[Neuronal LHRH system activity in an animal model of growth retardation].
OBJECTIVE
Mild and chronic energy restriction results in growth retardation with puberal delay, a nutritional disease known as nutritional dwarfing (ND). The aim of the present study was to assess the profile of hypothalamic luteinizing hormone-releasing hormone (LHRH) release, at baseline and under glutamate stimulation, in ND rats to elucidate gonadotrophic dysfunction. Reproductive ability during refeeding was also studied.


METHODS
At weaning, 60 male rats were assigned to two groups of 30 animals each: a control and an experimental group. Control rats were fed ad libitum with a balanced rodent diet. The experimental group received 80% of the diet consumed by the control group for 4 weeks. After 4 weeks of food restriction, the ND group was fed freely for 8 weeks. Ten rats from each group were sacrificed every 4 weeks for assays.


RESULTS
At week 4, body weight and length were significantly diminished in the experimental group vs. the control group (p<0.001). No changes were observed in LHRH baseline release, pulse frequency or amplitude in the experimental group compared with the control group at any time. However, under glutamate stimulation, LHRH release was significantly higher in ND rats than in control rats at week 4 (p<0.05). Refeeding the ND group allowed the rats to reach overall growth and reproductive ability.


CONCLUSIONS
The results of the present study suggest that the response to the facilitatory effect of glutamate on LHRH release in post-restricted ND rats is probably related to a lesser central nervous system maturation in relation to their chronological age. The adequate somatic growth and normal reproductive ability attained with refeeding suggest the reversibility of the two energetically costly processes compromised by global, mild and chronic food restriction.
Compagnucci
Cecilia Vanesa
CV
Facultad de Odontología, Universidad de Buenos Aires, Argentina.
Compagnucci
Gabriela Edith
GE
Lezón
Christian Esteban
CE
Chiarenza
Ana Patricia
AP
Elverdin
Juan Carlos
JC
Boyer
Patricia Mónica
PM
D000818:Animals; D004195:Disease Models, Animal; D004392:Dwarfism / Q000209:etiology*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism / Q000502:physiology*; D008297:Male; D009474:Neurons / Q000378:metabolism; D009748:Nutrition Disorders / Q000150:complications; D051381:Rats; D017208:Rats, Wistar
D007987:Gonadotropin-Releasing Hormone