Function
The 5-HT2 receptors (of which the 5-HT2B receptor is a subtype) mediate many of the central and peripheral physiologic functions of serotonin. Cardiovascular effects include contraction of blood vessels and shape changes in platelets; central nervous system effects include neuronal sensitization to tactile stimuli and mediation of some of the effects of phenylisopropylamine hallucinogens.
The 5-HT2B receptor subtype is involved in:
- CNS: presynaptic inhibition, behavioural effects
- Vascular: pulmonary vasoconstriction
- Cardiac: The 5-HT2B receptor regulates cardiac structure and functions as demonstrated by the abnormal cardiac development observed in 5-HT2B receptor null mice. The 5-HT2B receptor stimulation can also lead to pathological proliferation of cardiac valves fibroblasts, which with chronic overstimulation of 5-HT2B can lead to a severe valvulopathy. Moreover, 5-HT2B receptors were recently shown to be overexpressed in human failing heart and antagonists of 5-HT2B receptors were uncovered to prevent both angiotensin II or beta-adrenergic agonist-induced pathological cardiac hypertrophy in mouse.
- Serotonin transporter: 5-HT2B receptors regulate serotonin release via the serotonin transporter, and are important both to normal physiological regulation of serotonin levels in blood plasma, and with the abnormal acute serotonin release produced by drugs such as MDMA. Surprisingly however 5-HT2B receptor activation appears to be protective against the development of serotonin syndrome following elevated extracellular serotonin levels, despite its role in modulating serotonin release.
Read more about this topic: 5-HT2B Receptor
Famous quotes containing the word function:
“As a medium of exchange,... worrying regulates intimacy, and it is often an appropriate response to ordinary demands that begin to feel excessive. But from a modernized Freudian view, worryingas a reflex response to demandnever puts the self or the objects of its interest into question, and that is precisely its function in psychic life. It domesticates self-doubt.”
—Adam Phillips, British child psychoanalyst. Worrying and Its Discontents, in On Kissing, Tickling, and Being Bored, p. 58, Harvard University Press (1993)
“Advocating the mere tolerance of difference between women is the grossest reformism. It is a total denial of the creative function of difference in our lives. Difference must be not merely tolerated, but seen as a fund of necessary polarities between which our creativity can spark like a dialectic.”
—Audre Lorde (19341992)
“The information links are like nerves that pervade and help to animate the human organism. The sensors and monitors are analogous to the human senses that put us in touch with the world. Data bases correspond to memory; the information processors perform the function of human reasoning and comprehension. Once the postmodern infrastructure is reasonably integrated, it will greatly exceed human intelligence in reach, acuity, capacity, and precision.”
—Albert Borgman, U.S. educator, author. Crossing the Postmodern Divide, ch. 4, University of Chicago Press (1992)