Vasoactive peptides vasopressin

Vasoactive Peptides. More recent studies show a beneficial effect of vasopressin which should be evaluated further in clinical trials [58]. 

Thyrotropin-releasing hormone (TRH) Vasoactive intestinal peptide Vasopressin Yeast mating factors... 

Desmopressin acetate (arginine vasopressin) increases the factor VIII activity of patients with mild hemophilia A or von Willebrand disease. It can be used in preparation for minor surgery such as tooth extraction without any requirement for infusion of clotting factors if the patient has a documented adequate response. High-dose intranasal desmopressin (see Chapter 17 Vasoactive Peptides) is available and has been shown to be efficacious and well tolerated by patients. 

Vasopressin interacts with two types of receptors. Vi receptors are found on vascular smooth muscle cells and mediate vasoconstriction (see Chapter 17 Vasoactive Peptides). V2 receptors are found on renal tubule cells and mediate antidiuresis through increased water permeability and water resorption in the collecting tubules. Extrarenal V2-like receptors mediate release of coagulation... 

Mesangial cells are contractile and a number of vasoactive peptides are shown to induce MC contraction in vitro such as angiotensin II, vasopressin, norepinephrine, endothelin-1, thromboxane, adenosine, and serotonin [55], The absence of podocyte markers such as nephrin, podocin, Wilms tumor-1 (WT1), and endothelial markers such as von Willebrand factor and PECAM-1, is recommended. 

A. Classification and Prototypes Vasoactive peptides comprise a large class of endogenous substances that function as neurotransmitters as well as local and systemic hormones. The better-known peptides include angiotensin, bradykinin, atrial natriuretic peptide, endothelin, vasoactive intestinal peptide, substance P, calcitonin gene-related peptide, vasopressin, glucagon, and several opioid peptides. Vasopressin is discussed in Chapters 15 and 37, the opioid peptides in Chapter 31, and glucagon in Chapter 41. The peptides discussed in this chapter and their effects are summarized in Table 17-1. 

Peptides are used by most tissues for cell-to-cell communication. As noted in Chapters 6 and 21, they play important roles in the autonomic and central nervous systems. Several peptides exert important direct effects on vascular and other smooth muscles. These peptides include vasoconstrictors (angiotensin II, vasopressin, endothelins, neuropeptide Y, and urotensin) and vasodilators (bradykinin and related kinins, natriuretic peptides, vasoactive intestinal peptide, substance P, neurotensin, calcitonin gene-related peptide, and adrenomedullin). This chapter focuses on the smooth muscle actions of the peptides. 

The expression of the ET-1 gene is increased by growth factors and cytokines, including transforming growth factor-B (TGF-B) and interleukin 1 (IL-1), vasoactive substances including angiotensin II and vasopressin, and mechanical stress. Expression is inhibited by nitric oxide, prostacyclin, and atrial natriuretic peptide. 

A number of studies have investigated the effects of peripheral neurotransmitters and peptides on the regulation of NGF production and secretion by isolated organs or cells. For example, Hellweg et al. (1988) examined the influence of many agents on the release of NGF into the medium of cultured irides. Addition of neuropeptide Y, substance P, vasopressin, somatostatin, vasoactive intestinal polypeptide, neurotensin, serotonin and histamine all failed to change NGF levels. However, as these experiments were carried out in serum that may have resulted in maximal stimulation of the NGF gene, only inhibitory effects may have been detectable. Indeed, noradrenaline and dopamine were shown to be inhibitory. 

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