Related Experiment Video

Updated: Jun 18, 2026

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine
07:00

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine

Published on: February 26, 2019

Role of obestatin on growth hormone secretion: An in vitro approach

Yolanda Pazos1, Carlos J P Alvarez, Jesús P Camiña

  • 1Area de Endocrinología Molecular y Celular, Instituto de Investigación Sanitaria (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), Santiago de Compostela, Spain. yolanda.pazos@usc.es

Biochemical and Biophysical Research Communications
|November 10, 2009
PubMed

Insights

Obestatin activates MAPK signaling and triggers growth hormone release in rat pituitary cells. This peptide may act locally in the pituitary via autocrine or paracrine signaling.

Area of Science:

  • Endocrinology
  • Molecular Biology
  • Cell Signaling

Background:

  • Obestatin is a peptide hormone associated with ghrelin.
  • Its role in pituitary somatotroph cells (GC) is not fully understood.
  • Previous studies have not clarified its signaling pathways or direct effects on growth hormone (GH) secretion.

Purpose of the Study:

  • To investigate the signaling pathways activated by obestatin in rat tumor somatotroph cells.
  • To determine the effect of obestatin on growth hormone (GH) release.
  • To explore the potential autocrine/paracrine role of obestatin in the pituitary.

Main Methods:

  • Treatment of rat tumor somatotroph cells with obestatin.
  • Analysis of MAPK and Akt signaling pathways.
  • Measurement of cell proliferation.
  • Assessment of GH secretion over time.
  • Investigation of the obestatin transmembrane signaling cascade.

Main Results:

  • Obestatin activated MAPK signaling, specifically ERK1/2, but did not affect Akt or cell proliferation.
  • A signaling pathway involving G(i), PI3k, PKCepsilon, and Src was identified for ERK1/2 activation.
  • Obestatin acutely stimulated GH release within 30 minutes, peaking at 15 minutes.
  • GH secretion returned to control levels after 1 hour.
  • Obestatin was found to be secreted by the GC cells themselves.

Conclusions:

  • Obestatin directly stimulates GH release from somatotroph cells.
  • The signaling pathway for obestatin involves sequential activation of G(i), PI3k, PKCepsilon, and Src leading to ERK1/2 activation.
  • Obestatin's secretion by GC cells suggests a potential autocrine/paracrine role in pituitary function.

More Related Videos

Comparative Analysis of Human Growth Hormone in Serum Using SPRi, Nano-SPRi and ELISA Assays11:17

Comparative Analysis of Human Growth Hormone in Serum Using SPRi, Nano-SPRi and ELISA Assays

Published on: January 7, 2016

Related Concept Videos

Regulation of Hormone Secretion01:19

Regulation of Hormone Secretion

Regulation of hormone secretion is a finely tuned orchestration driven by various types of stimuli, encompassing neural, humoral, and hormonal signals. Environmental cues instigate neural stimuli, where action potentials traverse nerve fibers to reach their designated targets. An illustrative scenario is the body's response to stress, wherein the sympathetic nervous system releases epinephrine from the adrenal glands, inducing the well-known 'fight or flight' reaction.
Humoral stimuli,...
Hormones and Bone Tissue01:17

Hormones and Bone Tissue

The endocrine system produces and secretes hormones, which interact with the skeletal system. These hormones control bone growth, maintain bone once it is formed, and remodel it.
Hormones That Influence Osteoblasts and/or Maintain the Matrix
Several hormones are necessary for controlling bone growth and maintaining the bone matrix. The pituitary gland secretes growth hormone (GH), which, as its name implies, controls bone growth. This happens in several ways: first, it triggers chondrocyte...
Hormones Secreted by the Stomach01:25

Hormones Secreted by the Stomach

Enteroendocrine cells, accounting for only 1% of stomach epithelial cells, play a significant role in digestion and are classified by their digestive hormone secretions.
Each of these hormones secreted by different enteroendocrine cells plays a unique role in digestion. Here are a few examples:
Hormones of the Pituitary Gland01:27

Hormones of the Pituitary Gland

The small, pea-sized pituitary gland is located at the base of the brain. It is crucial in regulating various bodily functions, from growth to reproduction. The gland is divided into the anterior lobe and the posterior lobe. The secretory cell clusters in the pars distalis of the anterior pituitary lobe are controlled by hypothalamic regulators and synthesize six primary hormones.
The most abundantly secreted hormone from the anterior lobe is the growth hormone, which controls overall growth by...
Target Cell Response to Hormones01:22

Target Cell Response to Hormones

Hormones intricately bind to receptors on the surface or within target cells, initiating a cascade of cellular responses.
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
Intracellular Hormone Receptors01:08

Intracellular Hormone Receptors

Lipid-soluble hormones diffuse across the plasma and nuclear membrane of target cells to bind to their specific intracellular receptors. These receptors act as transcription factors that regulate gene expression and protein synthesis in the target cell