Localization and Secretion of Epidermal Growth Factor in the Parotid Gland and Its Intragastric Kinetics in Sheep.
From: Veterinary Physiology, Department of Biosciences, School of Veterinary Medicine, Rakuno Gakuen University, Japan. onaga@rakuno.ac.jp
Life sciences
- Publish Date: Sep 2006
- ISSN: 0024-3205
- Volume: 79
- Issue: 17
- Pages: 1616-29
- Medium: Print
- Language: English
- Citation (JAMA): Onaga Takenori, Shimizu Yasuhito, Hayashi Hideaki, et al. Localization and Secretion of Epidermal Growth Factor in the Parotid Gland and Its Intragastric Kinetics in Sheep.. Life Sci. Sep 2006;79:1616-29
Abstract
Ruminants secrete a large quantity of saliva that is rich in electrolytes; however, it remains unclear whether their parotid saliva contains epidermal growth factor (EGF). The present study was set up to examine the distribution of EGF and transforming growth factor-alpha (TGF-alpha) in the ovine parotid and submandibular glands and the salivary secretion of EGF-like binding activity (EGF-LBA) as the sum of EGF and TGF-alpha in conscious sheep. We also measured changes in the intragastric concentration of EGF-LBA in the ovine rumen and abomasum, and examined the effect of bilateral diversion of parotid saliva on intragastric EGF-LBA concentration in sheep. Both the ovine parotid and, to a lesser extent, the submandibular glands contained EGF-LBA. Immunohistochemical study showed that EGF and TGF-alpha-immunoreactivities were localized in the ductal epithelium in both glands. Transcriptional expression of EGF and TGF-alpha mRNA was demonstrated in both glands by reverse transcription-polymerase chain reaction (RT-PCR). In conscious sheep, the parotid gland continuously secreted EGF-LBA in the saliva before feeding, and the secretion of parotid EGF-LBA was markedly increased during feeding. After diversion of the parotid saliva for 1 week, EGF-LBA concentration in the ruminal fluid, but not in the abomasal fluid, decreased in the postprandial period, indicating that parotid EGF-LBA is a primary source of EGF-LBA for the rumen fluid during the postprandial period in sheep. Moreover, RT-PCR detected the expression of TGF-alpha mRNA in the rumen and abomasum and that of EGF in the abomasum, implying that these stomachs possibly supply, in part, EGF-LBA to the luminal fluid.
Mesh Headings (Keywords): Abomasum, Animals, Binding Sites, Chromatography, High Pressure Liquid, Epidermal Growth Factor, Fluorescent Antibody Technique, Indirect, Gene Expression, Immunoenzyme Techniques, Male, Parotid Gland, RNA, Messenger, Reverse Transcriptase Polymerase Chain Reaction, Rumen, Saliva, Sheep, Submandibular Gland, Transforming Growth Factor alpha
Check for Full Text / PubMed Unique Identifier (PMID): 16777144
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.