Innervation of the rat anterior and neurointermediate pituitary visualized by immunocytochemistry for the growth-associated protein GAP-43.

Paden, Charles M.; Moffett, Courtney; Benowitz, Larry I.

doi:10.1210/endo.134.1.8275967

Cited by 16 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Some of the authors speculated that the nerve fibers are autonomic in nature (Rosenfeld et al 1983;Mikkelsen et al 1989). Recently, tyrosine hydroxylase-and GAP-43-like immunoreactive (LI) nerve fibers were also found to be present (Paden et al 1994;Bayet et al 1994). Our recent studies have demonstrated substantial amounts of peptidergic nerve fibers in the anterior pituitary of several mammalian species.…”

Section: Introductionmentioning

confidence: 86%

Synaptic relationship of substance P-like-immunoreactive nerve fibers with gland cells of the anterior pituitary in the rat

Liu

Morris

1996

Cell and Tissue Research

View full text Add to dashboard Cite

Our previous studies have proved the presence of substantial amounts of peptidergic nerve fibers in the anterior pituitary of human, monkey, dog, and rat, and synaptic contacts have been demonstrated on corticotrophs and somatotrophs in the dog. The present study is aimed at investigating the synaptic relationship between axons and gland cells in the rat. The substance P-like-immunoreactive nerve fibers were studied immuno-electron-microscopically. They were nonmyelinated and varicose. Typical synaptic contacts between the fibers and every type of the hormone-secreting gland cell could be identified, most frequently on lactotrophs. No synaptic contacts were found on the folliculo-stellate cell. The synaptic contacts were of asymmetrical type with clusters of small round clear vesicles at the presynaptic site and scattered large dense-cored vesicles. This pattern of synaptic relationships was markedly different from that in the dog. The presence of synapses in the anterior pituitary of the rat implies a direct neural regulation of certain cells and strongly supports our hypothesis of neural-humoral dual regulation of this gland.

show abstract

Section: Introductionmentioning

confidence: 86%

Synaptic relationship of substance P-like-immunoreactive nerve fibers with gland cells of the anterior pituitary in the rat

Liu

Morris

1996

Cell and Tissue Research

View full text Add to dashboard Cite

show abstract

“…Omission of the primary antibody served as the immunohistochemi¬ cal method control. For specificity of the antibody and details of the preabsorption test, see Paden et al (1994). Preabsorption of the antibody with GAP-43 purified from neonatal rat cerebral cortex completely eliminated immunoreactivity in the pituitary.…”

Section: Immunohistochemistrymentioning

confidence: 99%

Evidence for axonal sprouting in the anterior pituitary following adrenalectomy in the rat

Meng²,

Benowitz³

et al. 1995

Journal of Endocrinology

Self Cite

View full text Add to dashboard Cite

Our recent studies have demonstrated the presence of peptidergic nerve fibers in the anterior pituitary of the rat. They were found to increase in number following adrenalectomy and the present study was aimed at investigating whether axonal sprouting could account for this increase. Antibody against the neuronal growth-associated protein GAP-43 was used as the probe. Four days following adrenalectomy GAP-43-like immunoreactivity was found to increase dramatically, mostly as varicosities surrounding the gland cells. The results suggest an active axonal sprouting following this hormone manipulation and strongly support our hypothesis of neural-humoral dual regulation of the mammalian anterior pituitary.

show abstract

“…The present data indicate that bGH can be neurally regulated. Additional data supporting the idea of neural as well as humoral regulation of the anterior pituitary have been published (20,22,23). Afferent pathways have been demonstrated that project from rat hindlimb muscles to hypothalamic nuclei, including the paraventricular nucleus, which has a known role in iGH regulation (5,7).…”

mentioning

confidence: 92%

“…Afferent pathways have been demonstrated that project from rat hindlimb muscles to hypothalamic nuclei, including the paraventricular nucleus, which has a known role in iGH regulation (5,7). Furthermore, nerve fibers have been observed surrounding hormone-producing cells (somatotrophs, corticotrophs) in the anterior pituitary of the rat, and these fibers are plastic in response to changes in the hormonal status of the animal (20,22,23). Finally, Hoffmann et al (16) have proposed a mechanism by which skeletal muscle afferent projections to the hypothalamus can function in the regulation of opioids.…”

mentioning

confidence: 99%

Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

Gosselink¹,

Grindeland

Roy

et al. 1998

Journal of Applied Physiology

View full text Add to dashboard Cite

There are forms of growth hormone (GH) in the plasma and pituitary of the rat and in the plasma of humans that are undetected by presently available immunoassays (iGH) but can be measured by bioassay (bGH). Although the regulation of iGH release is well documented, the mechanism(s) of bGH release is unclear. On the basis of changes in bGH and iGH secretion in rats that had been exposed to microgravity conditions, we hypothesized that neural afferents play a role in regulating the release of these hormones. To examine whether bGH secretion can be modulated by afferent input from skeletal muscle, the proximal or distal ends of severed hindlimb fast muscle nerves were stimulated ( approximately 2 times threshold) in anesthetized rats. Plasma bGH increased approximately 250%, and pituitary bGH decreased approximately 60% after proximal nerve trunk stimulation. The bGH response was independent of muscle mass or whether the muscles were flexors or extensors. Distal nerve stimulation had little or no effect on plasma or pituitary bGH. Plasma iGH concentrations were unchanged after proximal nerve stimulation. Although there may be multiple regulatory mechanisms of bGH, the present results demonstrate that the activation of low-threshold afferents from fast skeletal muscles can play a regulatory role in the release of bGH, but not iGH, from the pituitary in anesthetized rats.

show abstract

Innervation of the rat anterior and neurointermediate pituitary visualized by immunocytochemistry for the growth-associated protein GAP-43.

Cited by 16 publications

References 0 publications

Synaptic relationship of substance P-like-immunoreactive nerve fibers with gland cells of the anterior pituitary in the rat

Synaptic relationship of substance P-like-immunoreactive nerve fibers with gland cells of the anterior pituitary in the rat

Evidence for axonal sprouting in the anterior pituitary following adrenalectomy in the rat

Skeletal muscle afferent regulation of bioassayable growth hormone in the rat pituitary

Contact Info

Product

Resources

About