Effects of long-term ingestion of aspartame on hypothalamic neuropeptide Y, plasma leptin and body weight gain and composition

2002 ◽  
Vol 75 (1-2) ◽  
pp. 41-47 ◽  
Author(s):  
Bernard Beck ◽  
Arlette Burlet ◽  
Jean-Pierre Max ◽  
Alain Stricker-Krongrad
Endocrinology ◽  
2006 ◽  
Vol 147 (11) ◽  
pp. 5094-5101 ◽  
Author(s):  
En-Ju D. Lin ◽  
Amanda Sainsbury ◽  
Nicola J. Lee ◽  
Dana Boey ◽  
Michelle Couzens ◽  
...  

Neuropeptide Y (NPY) is a key regulator of energy homeostasis and is implicated in the development of obesity and type 2 diabetes. Whereas it is known that hypothalamic administration of exogenous NPY peptides leads to increased body weight gain, hyperphagia, and many hormonal and metabolic changes characteristic of an obesity syndrome, the Y receptor(s) mediating these effects is disputed and unclear. To investigate the role of different Y receptors in the NPY-induced obesity syndrome, we used recombinant adeno-associated viral vector to overexpress NPY in mice deficient of selective single or multiple Y receptors (including Y1, Y2, and Y4). Results from this study demonstrated that long-term hypothalamic overexpression of NPY lead to marked hyperphagia, hypogonadism, body weight gain, enhanced adipose tissue accumulation, hyperinsulinemia, and other hormonal changes characteristic of an obesity syndrome. NPY-induced hyperphagia, hypogonadism, and obesity syndrome persisted in all genotypes studied (Y1−/−, Y2−/−, Y2Y4−/−, and Y1Y2Y4−/− mice). However, triple deletion of Y1, Y2, and Y4 receptors prevented NPY-induced hyperinsulinemia. These findings suggest that Y1, Y2, and Y4 receptors under this condition are not crucially involved in NPY’s hyperphagic, hypogonadal, and obesogenic effects, but they are responsible for the central regulation of circulating insulin levels by NPY.


Metabolism ◽  
2012 ◽  
Vol 61 (6) ◽  
pp. 812-822 ◽  
Author(s):  
Esther Fuente-Martín ◽  
Miriam Granado ◽  
Cristina García-Cáceres ◽  
Miguel A. Sanchez-Garrido ◽  
Laura M. Frago ◽  
...  

2003 ◽  
Vol 284 (6) ◽  
pp. R1560-R1566 ◽  
Author(s):  
Amit Varma ◽  
Jing He ◽  
Lisa Weissfeld ◽  
Sherin U. Devaskar

We investigated the effect of repetitive postnatal (2–7 days) intracerebroventricular administration of neuropeptide Y (NPY) on food intake and body weight gain in the 3- to 120-day-old Sprague-Dawley rats. NPY caused a 32% transient increase in body weight gain with elevated circulating insulin concentrations within 24 h. This early intervention led to the persistence of hyperinsulinemia and relative hyperleptinemia with euglycemia in the 120-day-old female alone. This perturbation was associated with 50% suppression in adult female hypothalamic NPY concentrations and a 50–85% decline in NPY immunoreactivity in the paraventricular and arcuate nuclei. This change was paralleled by a ∼20% decline in food intake and body weight gain at 60 and 120 days. However, when exogenous NPY was stereotaxically reinjected into the paraventricular nucleus of the ∼120-day-old adult females who were pretreated with NPY postnatally, an increase in food intake and body weight gain was noted, attesting to no disruption in the NPY end-organ responsivity. We conclude that postnatal intracerebroventricular NPY has long-lasting effects that predetermine the resultant adult phenotype in a sex-specific manner.


1990 ◽  
Vol 124 (3) ◽  
pp. 381-386 ◽  
Author(s):  
M. J. Gardner ◽  
D. J. Flint

ABSTRACT Treatment of neonatal rats on days 2–5 with antibodies against rat GH (rGH) markedly reduced body weight gain and serum concentrations of insulin-like growth factor-I for 6–8 weeks in both females and males, after which weight gain normalized without evidence of catch-up growth. There were no significant effects on serum prolactin, tri-iodothyronine or corticosterone. Testis and ovarian weights were reduced, although only in proportion to body size. In females, but not males, the treated rats, though lighter, had increased fat deposition in the parametrial depot. Pituitary weight was considerably reduced over 100 days later, as was the pituitary content of GH, but not prolactin. The response to GH-releasing factor of both male and female rats was also greatly reduced at this time. Taken together with the fact that these rGH antibodies can bind directly to somatotrophs, we propose that the long-term effects of the antibodies are induced by specific somatotroph destruction. Journal of Endocrinology (1990) 124, 381–386


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