Featured Research

from universities, journals, and other organizations

Small details between 'in vivo' and 'in vitro' studies make for big differences

Date:
December 13, 2010
Source:
American Society for Cell Biology
Summary:
Exocytosis, the fundamental process by which cells secrete hormones such as insulin and other useful biological substances, is regulated far differently in life than in laboratory tissue cultures and explanted organs.

Small details between "in vivo" and "in vitro" studies make for big differences in understanding diabetes and other secretory dysfunctions

Exocytosis, the fundamental process by which cells secrete hormones such as insulin and other useful biological substances, is regulated far differently in life than in laboratory tissue cultures and explanted organs, according to research presented December 13 at the American Society of Cell Biology's 50th Annual Meeting in Philadelphia.

The unexpected findings that exocytosis regulation "in vivo" is not the same as the process long studied "in vitro" is a reminder of the gap between laboratory glassware experiments and the cell biology of living animals ⎯ and humans, said Roberto Weigert, Ph.D., of the National Institutes of Health (NIH), National Institute of Dental and Craniofacial Research (NIDCR).

During exocytosis, a cell internally packs up secretions and ferries them to the plasma membrane (PM) that demarcates the cell from its surroundings.

There, the packages, which are named secretory vesicles, fuse with the PM and then eject their contents. The process has been studied for decades in glassware experiments involving cultured cells and tissues.

Thanks to the optical imaging technology intravital microscopy. Weigert and colleagues were able to determine for the first time how exocytosis actually occurs in the salivary glands of a living mouse.

According to previous in vitro studies in the salivary glands, multiple secretory vesicles fuse with the PM, forming strings of vesicles in a process stimulated by two classes of chemical switches, muscarinic and beta-adrenergic receptors.

However, when the scientists examined the process in vivo, they saw the secretory vesicles fuse, not in strings, but one by one with the PM and only under stimulation from beta-adrenergic receptors.

Their additional in vivo studies revealed that the fusion step requires the assembly of a scaffold around the membrane of the vesicles.

This scaffold contains actin, a protein that forms filaments, and myosin II, a protein that binds to multiple actin filaments. When assembled, these molecules generate a contractile force that pushes the membranes and drives the fusion process to completion.

The molecular differences between in vivo and in vitro may seem minor but may have a large impact, said Weigert, because exocytosis is fundamental to understanding the basis of secretory dysfunctions such as diabetes in which insulin is transported in secretory vesicles.

Co-authors are Masedunskas, M. Sramkova, L. Parente, P. Amornphimoltham. K. Uzzun-Sales, T.H. Bugge, R. Weigert, all at National Institute of Dental and Craniofacial Research, NIH.

Funding: The Intramural Research Program of the NIH/NIDCR supported this research.


Story Source:

The above story is based on materials provided by American Society for Cell Biology. Note: Materials may be edited for content and length.


Cite This Page:

American Society for Cell Biology. "Small details between 'in vivo' and 'in vitro' studies make for big differences." ScienceDaily. ScienceDaily, 13 December 2010. <www.sciencedaily.com/releases/2010/12/101213101804.htm>.
American Society for Cell Biology. (2010, December 13). Small details between 'in vivo' and 'in vitro' studies make for big differences. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2010/12/101213101804.htm
American Society for Cell Biology. "Small details between 'in vivo' and 'in vitro' studies make for big differences." ScienceDaily. www.sciencedaily.com/releases/2010/12/101213101804.htm (accessed April 18, 2014).

Share This



More Plants & Animals News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Vermont Goat Meat Gives Refugees Taste of Home

Vermont Goat Meat Gives Refugees Taste of Home

AP (Apr. 18, 2014) Dairy farmers and ethnic groups in Vermont are both benefiting from a unique collaborative effort that's feeding a growing need for fresh and affordable goat meat. (April 18) Video provided by AP
Powered by NewsLook.com
First Ever 'Female Penis' Discovered In Animal Kingdom

First Ever 'Female Penis' Discovered In Animal Kingdom

Newsy (Apr. 18, 2014) Not only are these newly discovered bugs' sex organs reversed, but they also mate for up to 70 hours. Video provided by Newsy
Powered by NewsLook.com
Little Progress Made In Fighting Food Poisoning, CDC Says

Little Progress Made In Fighting Food Poisoning, CDC Says

Newsy (Apr. 18, 2014) A new report shows rates of two foodborne infections increased in the U.S. in recent years, while salmonella actually dropped 9 percent. Video provided by Newsy
Powered by NewsLook.com
The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins