2587
Journal of Cell Science 111, 2587-2594 (1998) Printed in Great Britain © The Company of Biologists Limited 1998 JCS9834
Sensory nerves affect the recruitment and differentiation of rat periovarian brown adipocytes during cold acclimation Antonio Giordano1, Manrico Morroni1, Flavia Carle2, Rosaria Gesuita2, Gian Franco Marchesi3 and Saverio Cinti1,* 1Institute 3Institute
of Normal Human Morphology, 2Department of Epidemiology, Biostatistics and Medical Information Technology and of Psychiatry, School of Medicine, University of Ancona, Ancona, Italy
*Author for correspondence at Istituto di Morfologia Umana Normale, Facoltà di Medicina, Via Tronto 10/A, 60020 Ancona, Italy (e-mail:
[email protected])
Accepted 3 July; published on WWW 13 August 1998
This paper is dedicated to the memory of Gian Franco Marchesi, who died after the completion of the manuscript.
SUMMARY Rat periovarian adipose tissue contains a low number of uncoupling protein-expressing brown adipocytes scattered into lobules of white fat. Their increase following cold acclimation is matched by a major increase in noradrenergic and neuropeptide Y-, substance P- and calcitonin gene-related peptide-containing nerves. To ascertain whether periovarian fat is provided with sensory nerves, and whether any relationship exists between such nerves (in particular the calcitonin gene-related peptidecontaining fibers found in cold-acclimated rats in close association with brown adipocytes) and brown fat recruitment, the effects of capsaicin desensitization on neuropeptide-containing nerves and brown adipocyte density were studied in the periovarian tissue of rats kept at 20°C and on a group acclimated to 4°C for 14 days. In both groups, systemic capsaicin administration
considerably reduced the expression of substance P and calcitonin gene-related peptide in vascular-nerve bundles and parenchyma. In cold-acclimated rats, the increase in brown adipocyte density was significantly checked by capsaicin administration (21.11 versus 7.96 brown adipocytes/mm2, P
