Neuroendocrinology Letters, Home
Neuroendocrinology Letters Vol. 21 No. 6 Contents
Contact us
Subscription info
Neuroendocrinology Letters incl. Psychoneuroimmunology & Chronobiology

 

Neuroendocrinology Letters incl. Psychoneuroimmunology & Chronobiology,
ISSN 0172–780X Copyright © 2000 Neuroendocrinology Letters

NEL VOL. 21 No. 6
ORIGINAL ARTICLE

2000; 21:441-446
pii: NEL21062000A003


Effect of aproteic diet and fasting on insulin, pancreatic noradrenaline and luteinizing hormone.
Changes after 24-hour refeeding

by Osvaldo J. Ponzo, Miguel A. Cresta, Dora Rondina, Berta Szwarcfarb,Juan C. Basabe & Pablo Scacchi

Keywords:
LH; insulin; noradrenaline; aproteic diet; fasting; refeeding

Abstract:

OBJECTIVE AND DESIGN: the objective of this study performed in adult male rats was to determine the alteration in glycemic, insulin and gonadotrophin luteinizing hormone secretion, and noradrenaline pancreatic concentration caused by fasting (F) and aproteic diet (Ap) during 7 and 21 days respectively, as well as the recovery after 24-hour refeeding with control diet (Co).


RESULTS: a significant decrease in glycemic levels was only achieved through fasting (F: 86 ± 5.1 mg %), when compared with controls (Co: 107 ± 5 mg %). In spite of the high levels of carbohydrates (89%) present in the aproteic diet, the animals fed with this diet showed no differences in glycemic levels (Ap: 120.3 ± 12.2 mg %), compared with controls. As a result of fasting and aproteic diet, there was a significant decrease in insulin (F: 8.67 ± 1.36; Ap: 5.7 ± 0.67; Co: 31 ± 3.4 uU/ml) and LH levels (F: 10.175 ± 1.74; Ap: 13.7 ± 4; Co: 29.83 ± 4.91 ng/ml). The refed recovered insulin (FR: 50.57 ± 6.63; ApR: 43.5 ± 6.85 uU/ml), but not LH levels (FR: 14.25 ± 3.54; ApR: 13.03 ± 4.25 ng/ml). A significant increase was observed in the pancreatic noradrenaline concentration (P<0.001) of rats receiving aproteic diet (889.9 ± 34.65 ng/mg tissue) and fasting during 7 days (827.5 ± 55.7 ng/mg tissue), compared with controls (531.1 ± 48.6 ng/mg tissue).


CONCLUSIONS: fasting and aproteic diets altered gonadal and metabolic control. When returning to a normal nutritional condition, only the metabolic control, not the reproductive function, could be recovered in the first 24 hours of refeeding. Malnutrition-induced hypoinsulinemia would be caused by an increase in a specific noradrenergic tone.

 

__________________________________________________________
Copyright © Neuroendocrinology Letters 2000
All rights reserved. No part may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or ortherwise, without prior written permission from the Editor-in-Chief editor@nel.edu