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Hypothalamic Distribution of Somatostatin m RNA Expressing Neurones Relative to Pubertal and Adult Changes in Pulsatile Growth Hormone Secretion in Mice
Author(s) -
Tan H. Y.,
Huang L.,
Simmons D.,
Veldhuis J. D.,
Steyn F. J.,
Chen C.
Publication year - 2013
Publication title -
journal of neuroendocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.062
H-Index - 116
eISSN - 1365-2826
pISSN - 0953-8194
DOI - 10.1111/jne.12078
Subject(s) - medicine , endocrinology , somatostatin , pulsatile flow , biology , hypothalamus , periventricular nucleus , secretion , median eminence , arcuate nucleus
The age‐associated decline in growth hormone ( GH) secretion may be a consequence of the reduction in the number of GH ‐releasing hormone ( GHRH ) positive neurones. However, it remains unclear whether an alteration in the number or distribution of somatostatin ( SST ) neurones contributes to this change. In the present study, we characterised the role of SST in modulating the change in pulsatile GH secretion in male C 57 B l/6 J mice throughout puberty and into early adulthood. We assessed pulsatile GH secretion in mice at 4, 8 and 16 weeks of age. These ages correspond to early pubertal, early adulthood and adulthood, respectively. We show an elevation in peak, total and pulsatile GH secretion coinciding with periods of rapid linear growth. Using in situ hybridisation and morphometric methods, we mapped the distribution of S st m RNA expression within the mouse brain relative to this change in pulsatile GH secretion. The results obtained show that altered pulsatile GH secretion in male mice from 4–16 weeks of age does not coincide with a significant change in the number of S st m RNA expressing neurones or an abundance of S st m RNA expression throughout the arcuate nucleus ( ARC ) and periventricular nucleus ( P e V ). Rather, we observed a progressive decline in S st m RNA expressing neurones within subnuclei of the paraventricular nucleus at this time. We conclude that structural changes in S st expression within the P e V and ARC may not reflect the observed decline in pulsatile GH secretion in mice from puberty into early adulthood.