Kappa agonists and vasopressin secretion
Hormone Research
|January 1, 1990
Summary
Specific kappa agonists decrease vasopressin secretion by affecting L-type calcium channels on nerve terminals. This action explains the diuretic effect observed with these opioid compounds.
Area of Science:
- Neuroendocrinology
- Pharmacology
Background:
- Opiate effects on vasopressin secretion are controversial due to receptor diversity and non-specific compounds.
- Recent advancements include specific kappa opioid receptor agonists.
Purpose of the Study:
- To elucidate the mechanism by which specific kappa agonists reduce vasopressin secretion.
- To investigate the role of kappa receptors and calcium channels in this process.
Main Methods:
- Utilized specific kappa opioid agonists.
- Investigated interactions with kappa receptors on neurohypophyseal nerve terminals and pituicytes.
- Examined potential coupling to L-type calcium channels.
Main Results:
- Specific kappa agonists induce diuresis without altering electrolyte excretion.
- Kappa receptor activation appears to decrease the efficacy of action potentials in evoking vasopressin release.
- This mechanism involves modulation of L-type calcium channels.
Conclusions:
- Kappa agonists reduce vasopressin secretion via a novel mechanism involving neurohypophyseal kappa receptors and L-type calcium channels.
- This pathway explains the diuretic effects of kappa agonists.
Related Concept Videos
01:17Hormonal Regulation of Blood Pressure
5.8K
Endocrinal or hormonal intervention in the cardiovascular system is predominantly exerted by the catecholamines - epinephrine and norepinephrine, as well as a slew of hormones that interact with renal function to modulate blood volume.
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction...
Epinephrine and Norepinephrine
The adrenal medulla releases epinephrine and norepinephrine, catecholamines that enhance and extend the sympathetic or "fight or flight" physiological response. These hormones escalate heart rate and the force of contraction...
5.8K
01:33Hormonal Regulation
35.6K
The renin-aldosterone system is an endocrine system which guides the renal absorption of water and electrolytes, thus managing blood pressure and osmoregulation. Activation of the system begins in the kidneys with a small cluster of cells adjacent to the afferent and efferent blood vessels of the renal corpuscle. As the nephrons are filtering blood, juxtaglomerular cells monitor blood pressure. If they detect a decrease in pressure, they release the hormone renin into the bloodstream.
35.6K
01:30Antihypertensive Drugs: Angiotensin II Receptor Blockers
2.4K
In the renin-angiotensin-aldosterone system, a hormone called angiotensin II plays a crucial role. It binds to the AT1 receptors in vascular smooth muscles coupled with Gq proteins. The activation of these receptors activates an enzyme called phospholipase C, which releases two molecules: inositol trisphosphate and diacylglycerol. These molecules cause a chain reaction that leads to the phosphorylation of myosin light chains and promotes interaction between actin and myosin, leading to smooth...
2.4K
01:23Antihypertensive Drugs: Vasodilators
2.0K
Vasodilators, primarily affecting the smooth muscles within arterial and venous walls, are commonly used for hypertension treatment. Medications such as minoxidil and hydralazine primarily target arteries and arterioles, while sodium nitroprusside acts on arterioles and venules. Minoxidil, functioning as a prodrug, is metabolized by hepatic sulfotransferase into its active form, minoxidil sulfate, after oral administration. This metabolite binds to the sulfonylurea receptor (SUR) component of...
2.0K
01:45Endocrine Signaling
67.7K
Endocrine cells produce hormones to communicate with remote target cells found in other organs. The hormone reaches these distant areas using the circulatory system. This exposes the whole organism to the hormone but only those cells expressing hormone receptors or target cells are affected. Thus, endocrine signaling induces slow responses from its target cells but these effects also last longer.
67.7K
01:30Adrenergic Agonists: Therapeutic Uses
1.6K
Adrenergic agonists have diverse therapeutic uses across various medical conditions and emergencies.
Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension.
Allergies and...
Emergency and Intensive Care Unit (ICU) applications: Pressor agents increase blood pressure, heart rate, and contractility in shock and organ failure situations. Dopamine can induce vasodilation and stimulate adrenoceptors. Endogenous catecholamines are effective in treating cardiogenic shock. α2-agonists like clonidine can reverse anesthesia-induced hypertension.
Allergies and...
1.6K