Increased hypothalamic neuropeptide Y concentrations in diabetic rat
- 1 June 1988
- journal article
- research article
- Published by American Diabetes Association in Diabetes
- Vol. 37 (6) , 763-772
- https://doi.org/10.2337/diabetes.37.6.763
Abstract
Central and lateral hypothalamic concentrations of 10 regulatory peptides were measured by radioimmunoassay in streptozocin-induced diabetic (STZ-D) and matched control rats between 1 day and 14 wk after diabetes induction. After 2 wk, both central and lateral hypothalamic neuropeptide Y (NPY) concentrations in STZ-D rats were consistently higher than those found in control rats, with significant 30–50% increases at 4 wk in the central hypothalamus, and at 6 and 14 wk in both central and lateral hypothalamus. Immunocytochemical studies in 4- and 6-wk STZ-D animals showed the appearance of intensely NPY-positive swollen cell bodies in the supraoptic nucleus and a subjective increase in NPY staining of medial hypothalamic nerve fibers. Central hypothalamic concentrations of three other peptides were significantly greater in STZ-D animals than those in control animals at single points (neurotensin, 1 day; calcitonin gene-related peptide, 2 wk; neurokinin, 4 wk). Hypothalamic concentrations of the other six peptides examined (bombesin, galanin, neuromedin B, substance P, somatostatin, and vasoactive intestinal peptide) did not differ significantly between STZ-D and control groups at any time. However, galanin immunostaining in the supraoptic and magnocellular paraventricular nuclei was strikingly concentrated in a reduced number of distended cell bodies. Hypothalamic peptide changes in STZ-D could be related to metabolic disturbance, changes in energy and water balance, altered pituitary function, or other factors. Persistently elevated concentrations of NPY, a very potent central stimulant of eating and drinking, may mediate the hyperphagia and polydipsia characteristic of STZ-D.This publication has 3 references indexed in Scilit:
- Distribution and chromatographic characterisation of CGRP-like immunoreactivity in the brain and gut of the ratRegulatory Peptides, 1985
- Neuropeptide Y injected in the paraventricular hypothalamus: a powerful stimulant of feeding behavior.Proceedings of the National Academy of Sciences, 1985
- The effect of streptozotocin-induced diabetes on pituitary and hypothalamic endorphin equivalentsLife Sciences, 1983