Pulsatile secretion

<p>Pulsatile secretion is a <a href="/facts/Biochemistry/fa2pWEBp">biochemical</a> phenomenon observed in a wide variety of <a href="/facts/Cell_(biology)/bLM9UQvy">cell</a> and <a href="/facts/Tissue_(biology)/H7CpML7A">tissue</a> types, in which <a href="/facts/Chemical_substance/EWcXU41d">chemical</a> products are secreted in a regular  temporal pattern.  The most common cellular products observed to be released in this manner are intercellular signaling molecules such as <a href="/facts/Hormone/WFnBnINJ">hormones</a> or <a href="/facts/Neurotransmitter/LlpYFSU3">neurotransmitters</a>.  Examples of hormones that are secreted pulsatilely include <a href="/facts/Insulin/oXG0myt1">insulin</a>, <a href="/facts/Thyrotropin/w8ettSpY">thyrotropin</a>, <a href="/facts/TRH/losJq69G">TRH</a>, <a href="/facts/Gonadotropin-releasing_hormone/hSsFPpdj">gonadotropin-releasing hormone</a> (GnRH) and <a href="/facts/Growth_hormone/SLEJ1fws">growth hormone</a> (GH).  In the nervous system, pulsatility is observed in oscillatory activity from <a href="/facts/Central_pattern_generator/R3FouI2u">central pattern generators</a>. In the heart, <a href="/facts/Cardiac_pacemaker/j4Rn2Gfm">pacemakers</a> are able to work and secrete in a pulsatile manner. A pulsatile secretion pattern is critical to the function of many hormones in order to maintain the delicate <a href="/facts/Homeostasis/rloTGAHa">homeostatic</a> balance necessary for essential life processes, such as <a href="/facts/Development_of_the_human_body/S97k10C2">development</a> and <a href="/facts/Reproduction/nNu0F5Dy">reproduction</a>. Variations of the concentration in a certain frequency can be critical to hormone function, as evidenced by the case of <a href="/facts/GnRH_agonist/g8awqhvS">GnRH agonists</a>, which cause functional inhibition of the receptor for GnRH due to profound <a href="/facts/Downregulation/6nRoa28r">downregulation</a> in response to constant (tonic) stimulation.  Pulsatility may function to sensitize target tissues to the hormone of interest and <a href="/facts/Downregulation_and_upregulation/6nRoa28r">upregulate</a> receptors, leading to improved responses.  This heightened response may have served to improve the animal's fitness in its environment and promote its evolutionary retention.
</p><p>Pulsatile secretion in its various forms is observed in:
</p>
<ul><li><a href="/facts/Hypothalamic%25E2%2580%2593pituitary%25E2%2580%2593gonadal_axis/0G9ALlpQ">Hypothalamic–pituitary–gonadal axis</a> (HPG) related hormones</li>
<li><a href="/facts/Glucocorticoid/2P91Aj3S">Glucocorticoids</a></li>
<li><a href="/facts/Insulin/oXG0myt1">Insulin</a></li>
<li><a href="/facts/Growth_hormone/SLEJ1fws">Growth hormone</a></li>
<li><a href="/facts/Parathyroid_hormone/Dh7Uld78">Parathyroid hormone</a></li></ul>

Pulsatile secretion open-in-new

Pulsatile secretion