Paracrine neurotransmission

The primary catabolic pathway for 5-HT is oxidative deamination by the enzyme monoamine oxidase 237 In addition to classical synaptic transmission, 5-HT may relay information by volume transmission or paracrine neurotransmission 238 5 -HT may be involved in a wide variety of behaviors by setting the tone of brain activity in relationship to the state of behavioral arousal/activity 238... 

Somatostatin acts on various organs, tissues and cells as neurotransmitter, paracrine/autocrine and endocrine regulator on cell secretion, smooth muscle contractility, nutrient absorption, cell growth and neurotransmission [1]. Some of its mainly inhibitory effects are listed in Table 1. Somatostatin mediates its function via a family of heptahelical G-protein-coupled receptors termed... 

Nitric oxide (NO) is a common product of the metabolism of arginine in many tissues. It is thought to be an important paracrine vasodilator, and it may also play a role in cell death and in neurotransmission. Nitric oxide is tilso released from several important vasodilator drug molecules (see below). 

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