Vasoactive Peptides

Question 1

Angiotensin converting enzyme (ACE) is also known as:

Answer 1

• peptidyl dipeptidase

- kininase II

Question 2

Excessive production of angiotensin II results in:

Answer 2

hypertension and disorders of hemodynamics

Question 3

Is angiotensin II more or less potent than NE?

Answer 3

40x more potent

Question 4

a potent mitogenic agent for vascular and cardiovascular muscle cells; may contribute to cardiac hypertrophy

Answer 4

angiotensin II

Question 5

List 3 ways that the formation of angiotensin II may be blocked.

Answer 5

1. Blocking renin secretion/action
2. Blocking conversion of Ang I to Ang II
3. Blocking angiotensin receptors

Question 6

What are the additional effects of ACE inhibitors besides blocking the conversion of Ang I to Ang II?

Answer 6

They also inhibit degradation of other vasopeptides, like bradykinin**, substance P, and enkephalin.

Question 7

What contributes to the observed hypotensive effect of ACE inhibitors?

Answer 7

blockage of bradykinin metabolism/degradation

Question 8

glycoprotein enzymes produced in liver as prekallikreins and present in plasma, kidney, pancreas, GI tract, sweat glands, salivary glands

Answer 8

kallikreins

Question 9

also known as Fletcher factor and promotes coagulation process via intrinsic system

Answer 9

plasmatic prekallikrein

Question 10

Bradykinin is released by ________.

Answer 10

plasma kallikrein (plasma kallikrein cleaves high molecular weight kininogen to generate bradykinin)

Question 11

List some of the hemodynamic effects of the kinins.

Answer 11

• 10x more potent than histamine
• stimulate release of NO and prostaglandins
• promote water and solution passage from blood to ECF, resulting in edema

Question 12

What is the role of kinins in inflammation and pain?

Answer 12

promote redness, local heat, swelling, and pain; they are potent algesic agents that produce pain by nociceptive afferents in skin and viscera

Question 13

What are the main receptors for kinins?

Answer 13

B1 and B2 (B1 are the predominant receptors for mediating biologic responses of kinins)

Question 14

Vasopeptide inhibitors are a new class of drugs that do what?

Answer 14

inhibit metalloproteases, increase levels of natriuretic peptides, and decrease formation of ang II (“lat” drugs)
*enhance vasodilation, reduce vasoconstriction, and increase sodium excretion