Currently, five neuropeptides are known to be involved in the control of bone homeostasis, including calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY
), substance P (SP), vasoactive intestinal peptide (VIP), and tyrosine hydroxylase (TH) (1,2).
The mechanisms of action of NPY
and GAL are also affected by additional factors.
Stress hormones cortisol (Panossian et al., 2007; Olsson et al., 2009), neuropeptide Y (NPY
) (Panossian et al., 2012), and other circulating mediators of the stress response such as nitric oxide (Panossian et al., 2007), membrane bound G-protein receptors (Panossian et al., 2013) and molecular chaperons Hsp70 (Panossian et al., 2009, 2012).
(human, rat, catalog number H-6375) was purchased from Bachem AG, Switzerland.
mRNA expression in the hypothalamus of GERD rats significantly increased on day 10 (Figure 5(a)), whereas AgRP mRNA expression significantly increased from day 3 (Figure 5(b)).
, a 36--amino acid peptide, is widely distributed in the brain.
Study co-author Dr Kenny Chi Kin Ip said: "We discovered that when we switched off the production of NPY
in the amygdala [it handles our emotions and anxiety], weight gain was reduced.
Since neuropeptide Y (NPY
) was first extracted from a mammalian brain in 1982 (Tatemoto et al., 1982), many studies have found that the npy
mRNA is expressed in the central nervous system, peripheral nervous system and peripheral tissues of mammals and teleosts, with the highest expression in the brain (Chen and Li, 2005; Kehoe and Volkoff, 2007; Malmstrom, 2001; Murashita et al., 2009).
Following a hunch that this molecule could be driving the additional weight gain linked to stress, the researchers turned off the process that produces NPY
To understand what might control the NPY
boost under stress, the scientists analysed the nerve cells that produced NPY
in the amygdala and found they had receptors, or 'docking stations', for insulin -- one of the hormones which control our food intake.
However, the researchers found that nerve cells that produced NPY
in the amygdala had receptors for insulin, a hormone which control food intake.
However, its modulating effect on NPY
which might contribute to antidepressant activity cannot be ruled out.