CR effects in sheep brains

[Guest guest]

Hi All,

What is the %CR is difficult to estimate for sheep for which there foods were

" pasture hay (Normally Fed) or a restricted diet of approximately 500 gm of

grass

hay/day/sheep (Lean). The Lean animals also received straw to add bulk to their

diet " and in which " Normally Fed animals weighed 60.2±0.8kg and Lean animals

weighed

39±1 kg (P<0.001). "

It seems from the pdf-available to all free below paper that " These findings

provide

an anatomical evidence of central mechanism/s by which appetite regulating

peptides

and dopamine could regulate [growth hormone] secretion. Increased input to

[somatostatin] cells in Lean animals may be inhibitory and permissive of

increased

[growth hormone]. The appearance of [neuropeptide Y] in [Growth Hormone

Releasing

Hormone] cells of Lean animals may be a mechanism for regulation of increasing

[grpwth hormone] secretion with reduced adiposity. "

Endocrinology. 2005 Aug 4; [Epub ahead of print]

Reduction in Adiposity Affects the Extent of Afferent Projections to Growth

Hormone

Releasing Hormone (GHRH) and Somatostatin (SRIF) Neurons and the Degree of

Co-localization of Neuropeptides in GHRH and SRIF Cells of the Ovine

Hypothalamus.

Iqbal J, Manley TR, Ciofi P, e IJ.

Various neuropeptides and neurotransmitters affect growth hormone (GH) secretion

by

acting on growth hormone releasing hormone (GHRH) and somatostatin (SRIF) cells.

GH

secretion is also affected by alteration in adiposity, which could be via

modulation

of GHRH and SRIF cells. We quantified co-localization of neuropeptides in GHRH

and

SRIF cells and afferent projections to these cells in Lean (food restricted) and

Normally Fed sheep (n = 4/group). The number of GHRH-immunoreactive (IR) cells

in

the arcuate nucleus was higher in Lean animals, but the number of SRIF-IR cells

in

periventricular nucleus was similar in the two groups. A subpopulation of

GHRH-IR

cells co-localized neuropeptide Y in Lean animals, but this was not seen in

Normally

Fed animals. GHRH/galanin co-localization was higher in Lean animals with no

difference in numbers of GHRH/tyrosine hydroxylase (TH) or GHRH/galanin-like

peptide

cells. SRIF/enkephalin co-localization was lower in Lean animals. The % of GHRH

neurons receiving SRIF input was similar in Lean and Normally Fed animals, but

more

GHRH cells received input from enkephalin afferents in Normally Fed animals. The

%

of SRIF cells receiving GHRH, neuropeptide Y, galanin and orexin afferents was

higher in Lean animals. These findings provide an anatomical evidence of central

mechanism/s by which appetite regulating peptides and dopamine could regulate GH

secretion. Increased input to SRIF cells in Lean animals may be inhibitory and

permissive of increased GH. The appearance of NPY in GHRH cells of Lean animals

may

be a mechanism for regulation of increasing GH secretion with reduced adiposity.

PMID: 16081637

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=pubmed & dopt=Abstra\

ct & list_uids=16081637 & query_hl=10

http://tinyurl.com/7nzbn

http://endo.endojournals.org/cgi/rapidpdf/en.2005-0622v1

Al Pater, PhD; email: old542000@...

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