Blood to brain transfer of leptin in normal and interleukin-1 beta-treatedmale rats

Citation
S. Reichlin et al., Blood to brain transfer of leptin in normal and interleukin-1 beta-treatedmale rats, ENDOCRINOL, 141(6), 2000, pp. 1951-1954
Citations number
36
Categorie Soggetti
Endocrinology, Nutrition & Metabolism
Journal title
ENDOCRINOLOGY
ISSN journal
00137227 → ACNP
Volume
141
Issue
6
Year of publication
2000
Pages
1951 - 1954
Database
ISI
SICI code
0013-7227(200006)141:6<1951:BTBTOL>2.0.ZU;2-Q
Abstract
To test the hypothesis that leptin was secreted from the brain into the blo od of the rat, its concentration was measured in the superior sagittal sinu s (SSS; which drains the cerebral cortex) and aortic blood of normal fastin g male rats and rats that had been treated with iv or intracerebroventricul ar (icv) injections of interleukin-1 beta (IL-1 beta; 100 ng), a cytokine p reviously shown to induce peripheral leptin secretion. Plasma levels of lep tin in SSS were slightly, but significantly, less than those in the aorta i n control, saline-injected rats (0.99 +/- 0.07 vs. 1.19 +/- 0.10 ng/ml; n = 15; P = 0.03) and in rats injected with human IL-1 beta iv (1.56 +/- 0.12 vs. 1.92 +/- 0.15 ng/ml; n = 23; P = 0.004) or icy (1.38 +/- 0.11 vs. 1.57 +/- 0.12 ng/ml; n = 23; P = 0.008). IL-1 beta by either the iv or icy route significantly increased leptin levels in the aorta [1.19 +/- 0.10 vs. 1.92 +/- 0.15 ng/ml (P = 0.0002) and 1.19 +/- 0.10 vs. 1.57 +/- 0.12 ng/ml (P = 0.022), respectively]. SSS levels of leptin were also raised after iv or i cy injection (P = 0.0002 and P = 0.0053, respectively). These findings demo nstrate a net uptake of leptin by the cerebral cortex from peripheral blood in both normal and IL-1 beta-treated animals and show that peripheral bloo d levels of leptin are increased by IL-1 beta whether administered icy or i v.