Catecholamines, Biology

Assignment Help:

Catecholamines increase activation of Ca2+ via beta-adrenergic receptors and the adenyl cyclase system.

Dopamine has both alpha and beta and dopaminergic effects.  Its beta effects in the heart occur largely through the release of endogenous norepinephrine, which may be largely depleted in a failing heart. As such, the benefits of dopamine administration, if any, occur at low doses (e.g., 0.02 mg/kg per minute), where it may induce renal arterial vasodilatation. In general, it is employed in association with more potent inotropic agents (e.g., dobutamine).

Dobutamine characterized by an increase in cardiac output and a decrease in ventricular filling pressure with little change in heart rate. There is modest rise in arterial pressure and decrease in peripheral vascular resistance. The positive inotropic activity of dobutamine is mediated by direct stimulation of beta-adrenergic receptors in the myocardium.

Dobutamine infusion generally is begun at 2 µg/kg per minute and titrated to optimize cardiac output while reducing LV filling pressure. The major side effects of dobutamine are an excessive increase in heart rate with high doses and ventricular arrhythmias.


Related Discussions:- Catecholamines

Agro industrial-packaging, Packaging Compound feeds, whether in mash o...

Packaging Compound feeds, whether in mash or pellet form, are packed in bags or stored in bins. Bags may be filled directly from mixers, pellet coolers or holding bins and wei

Function of the cornified layer of the skin, What are the main functions of...

What are the main functions of (a) the basal (Malpighian) layer, (b) the cornified layer of the skin?   (a) The basal (Malpighian) layer makes new skin cells and the pigment

Diabetic with hypertension, Kidney Disease   The target BP in chronic k...

Kidney Disease   The target BP in chronic kidney disease is set at 130/80.  This will retard the progression of renal function. The drugs recommended are the ACEI/ARBs. These c

What is the way of life of sponges, Q What is the way of life of sponges? ...

Q What is the way of life of sponges? Sponges live exclusively in an aquatic environment and they are attached by their base to a substrate fixation ground. Sponges are filteri

Iron age, Explain the factors that led to the decline of Science in Europe ...

Explain the factors that led to the decline of Science in Europe during iron age

Some important zoonoses-rabies , Some important zoonoses Zoonoses are ...

Some important zoonoses Zoonoses are a heterogeneous group of diseases with a variety of causative agents. On the basis of causative agents, they are grouped into bacterial, p

Explain isozymes, ISOZYMES Sometimes an  enzyme present  in  the  same ...

ISOZYMES Sometimes an  enzyme present  in  the  same  organism is  found  to  have different molecular forms but  catalyzing the  same  reaction. These are called  isozymes. Th

Explain composition of amino acid, Explain amino acid composition In te...

Explain amino acid composition In terms of amino acid composition, high radiation doses such as those required for sterilization (e.g. 25-27Kgy), do not change the content of c

Microscopic examination of sputum, Question 1 Discuss briefly the collecti...

Question 1 Discuss briefly the collection and examination of pericardial fluid Question 2 Discuss the following Collection of CSF Physical examination of CSF

DNA fingerprinting, This method makes use of a common, but peculiar, group ...

This method makes use of a common, but peculiar, group of DNA sequences known as minisatellites. High levels of variation in the numbers of these repeated units are used in "DNA fi

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd