Neostigmine injection in the hippocampus activates thermogenesis by
an increase in sympathetic activity and t4-to-t3 conversion.
Monda, M., A. Papa, G. Brizzi, and B. De Luca.
Department of Human Physiology and Integrated Biological Functions
"F. Bottazzi", Second University of Naples, Via
Costantinopoli 16, I-80138, Naples, Italy
APStracts 3:0011R, 1996.
The firing rate of the nerves innervating interscapular brown adipose
tissue (IBAT), IBAT and colonic temperatures (TIBAT and TC) and
oxygen (O2) consumption were monitored in urethane-anesthetized male
Sprague-Dawley rats. These variables were measured for 40 min before
(baseline values) and 40 min after a neostigmine (5x10-7mol/1ml) or
saline injection in the hippocampus. The blood level of
triiodothyronine and thyroxine (T3 and T4) and the 5'-deiodinating
activity of IBAT, liver and kidneys were determined in other rats
with neostigmine or saline injection. The results showed that
neostigmine injection increased firing rate, TIBAT, TC, O2
consumption, blood level of T3 and 5'-deiodinating activity of IBAT.
No change was found in the T4 level and in 5'-deiodinating activity
of the liver and kidneys. These findings suggest that neostigmine
injection in the hippocampus increases heat production by stimulating
sympathetic nerves to IBAT and by elevating the blood level of T3.
Received 7 August 1995; accepted in final form 11 December 1995.
APS Manuscript Number R498-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 22 January 96