Adrenergic Receptors

There are two types of adrenergic receptors, with subdivisions within each:

1. a-Adrenergic receptors arAdrenergic receptors are located on postsynaptic effector cells such as those on the smooth muscles of the vascular, genitourinary, intestinal, and cardiac systems. Additionally, in humans these receptors are located within the liver. a2-Adrenergic receptors inhibit the release of certain neurotransmitters. For example, at the presynaptic level in certain adrenergic nerve cells, these receptors inhibit norepinephrine release, whereas in cholinergic neurons they are responsible for inhibiting acetylcho-line release. a2-Adrenergic receptors are also located in postjunctional sites such as the b cells of the pancreas, in platelets, and in vascular smooth muscle. Although there are at least two subtypes of both a1- and a2-adrenergic receptors, the details concerning the actions and localization that would differentiate these particular subtypes have not been worked out.

2. b-Adrenergic receptors brAdrenergic receptors have been located in the heart, the juxtaglomerular cells of the kidney, and the parathyroid gland. b2-Adrenergic receptors have been identified in the smooth muscles of the vascular, gastrointestinal, genitourinary, and bronchial structures. Additionally, b2-adrenergic receptors have been located in skeletal muscle and the liver as well as on the a cells of the pancreas, which are responsible for glucagon production. b3-Adrenergic receptors are reported to be located in adipose tissue.

Breaking Bulimia

Breaking Bulimia

We have all been there: turning to the refrigerator if feeling lonely or bored or indulging in seconds or thirds if strained. But if you suffer from bulimia, the from time to time urge to overeat is more like an obsession.

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