Search

Your search keyword '"Phenylethanolamine N-methyltransferase"' showing total 4 results
Start Over Descriptor "Phenylethanolamine N-methyltransferase" Publication Type Electronic Resources
4 results on '"Phenylethanolamine N-methyltransferase"'

1. Catecholamine synthesising enzymes in the programming of hypertension by mild protein restriction during gestation

Author

Copin, Nane

Subjects
616, Phenylethanolamine N-methyltransferase
Abstract

The expression of TH and PNMT mRNA was analysed by Northern-blotting in the adrenal of female offspring born to dams fed either a diet mildly restricted in protein content (9% casein), but otherwise isocaloric, or fed a control diet (18% casein) throughout gestation. The blood pressure effects (measured by tail-cuff plethysmography) of twice daily, for a 7-day period, intraperitoneal administration of a PNMT inhibitor, versus vehicle, were analysed in low-protein and control male and female offspring. As previously described, offspring from dams fed the low-protein diet had significantly elevated blood pressure in postnatal life compared with the control of offspring. Levels of TH and PNMT mRNA expression in the adrenal of the low-protein offspring were not significantly different from those of the control offspring at either 2, 4, 8 or 12 weeks of age. At 16 weeks of age, low-protein offspring displayed a significantly greater adrenal TH mRNA expression than the controls. Blockade of central and peripheral adrenaline synthesis at 8 weeks of age with the PNMT inhibitor markedly reduced heart rate and tended to lower blood pressure in all offspring after 7 days compared with vehicle-treated offspring. Importantly, the PNMT inhibitor tended to exert a prolonged blood pressure reduction specifically in the low-protein female offspring, up to 3 weeks following withdrawal of the treatment. Adrenal PNMT activity was not different between low-protein and control offspring at 8 weeks of age. Therefore, the greater long-term blood pressure reduction in the low-protein female offspring following PNMT inhibition may be centrally mediated. The data suggest that the mechanisms by which hypertension is initiated may not depend on an increased synthesis of catecholamines from the adrenal. However, increased levels of adrenaline synthesis by PNMT in central adrenergic neurones may play a contributory role. Increased adrenal catecholamine synthesis may, once hypertension is established, participate in its maintenance.

Published
2002

2. Three-dimensional image reconstruction of distribution of Pnmt+ cell-derived cells in murine heart.

Author

Ni, Haibo, Ni, Haibo, Wang, Yange, Crawford, William, Zhang, Shanzhuo, Cheng, Longxian, Zhang, Henggui, Lei, Ming, Ni, Haibo, Ni, Haibo, Wang, Yange, Crawford, William, Zhang, Shanzhuo, Cheng, Longxian, Zhang, Henggui, and Lei, Ming

Abstract

Elucidating the function of specific cell types in a highly complex multicellular system such as the heart often requires detailed anatomic reconstruction. We recently described a distinctive class of phenylethanolamine n-methyltransferase (Pnmt+) cell-derived cardiomyocytes (PdCMs), a new cardiomyocyte population with a potential endocrine role. In this dataset, a 3D reconstruction was carried out to visualise the distribution of PdCMs throughout the murine heart. Rigid registration (stiff rotation and translation) was applied to properly align the fused heart slice images based on landmarks using TrakEM2, an open source plug-in in Fiji. The registered slices were then analysed and reconstructed using MATLAB (MATLAB®. Version 8.3.0.532). The final reconstructed 3D volume was 561×866×48 pixels (corresponding to spatial resolutions of 5.8, 8.9 and 2.5 mm in the x-, y- and z-direction respectively), and visualised in Paraview. The reconstruction allows for detailed analyses of morphology, projections and cellular features of different cell types, enabling further geometrical and topological analyses. Image data can be accessed and viewed through Figshare.

Published
2017

3. Optogenetic Control of Heart Rhythm by Selective Stimulation of Cardiomyocytes Derived from Pnmt+ Cells in Murine Heart.

Author

Wang, Yanwen, Wang, Yanwen, Lin, Wee, Crawford, William, Ni, Haibo, Bolton, Emma, Khan, Huma, Shanks, Julia, Bub, Gil, Wang, Xin, Paterson, David, Zhang, Henggui, Galione, Antony, Ebert, Steven, Terrar, Derek, Lei, Ming, Wang, Yanwen, Wang, Yanwen, Lin, Wee, Crawford, William, Ni, Haibo, Bolton, Emma, Khan, Huma, Shanks, Julia, Bub, Gil, Wang, Xin, Paterson, David, Zhang, Henggui, Galione, Antony, Ebert, Steven, Terrar, Derek, and Lei, Ming

Abstract

In the present study, channelrhodopsin 2 (ChR2) was specifically introduced into murine cells expressing the Phenylethanolamine n-methyltransferase (Pnmt) gene, which encodes for the enzyme responsible for conversion of noradrenaline to adrenaline. The new murine model enabled the identification of a distinctive class of Pnmt-expressing neuroendocrine cells and their descendants (i.e. Pnmt+ cell derived cells) within the heart. Here, we show that Pnmt+ cells predominantly localized to the left side of the adult heart. Remarkably, many of the Pnmt+ cells in the left atrium and ventricle appeared to be working cardiomyocytes based on their morphological appearance and functional properties. These Pnmt+ cell derived cardiomyocytes (PdCMs) are similar to conventional myocytes in morphological, electrical and contractile properties. By stimulating PdCMs selectively with blue light, we were able to control cardiac rhythm in the whole heart, isolated tissue preparations and single cardiomyocytes. Our new murine model effectively demonstrates functional dissection of cardiomyocyte subpopulations using optogenetics, and opens new frontiers of exploration into their physiological roles in normal heart function as well as their potential application for selective cardiac repair and regeneration strategies.

Published
2017

Catalog

Books, media, physical & digital resources
See catalog results