Biomaterial Database

Secretin and somatostatin as modulators of electrolyte transport in guinea pig gallbladder epithelium. 1993

G Sprakties, and H J Macherey, and K U Petersen

Institut für Pharmakologie und Toxikologie, Medizinische Fakultät, Rheinisch-Westfälische Hochschule Aachen, Federal Republic of Germany.

Effects of secretin and somatostatin on electrolyte transport by guinea pig gallbladder epithelium were investigated in vitro. Tissues were mounted in Ussing-type chambers and continuously short-circuited to measure tissue conductance, short-circuit current (Isc) and transepithelial voltage. Unidirectional fluxes (from mucosa to serosa: Jms; from serosa to mucosa: Jsm) of Na+ and Cl- were determined simultaneously by using tracer techniques and those of HCO3- by pH-stat titration. Serosal addition of secretin caused concentration-dependent increases in tissue conductance, Isc and (lumen-negative) transepithelial voltage. At 1.3 x 10(-8) M, secretin raised net HCO3- secretion by 1.5 mumol/cm2/hr, due to inhibition of Jms (from approximately 1.2 to approximately 0.7 mumol/cm2/hr) and stimulation of Jsm (from approximately 3.7 to approximately 4.7 mumol/cm2/hr). The associated increase in Isc by approximately 3.8 mumol/cm2/hr (up from approximately 0.5 mumol/cm2/hr) was not different from net HCO3-secretion (approximately 4 mumol/cm2/hr). Neither Na+ nor Cl- net fluxes accounted for secretin-induced Isc, both being absorbed at equal rates (Na+: approximately 2.7, down from approximately 4.6 mumol/cm2/hr; Cl-: approximately 2.5, down from approximately 6.4 mumol/cm2/hr). Secretin caused a 10-fold rise of luminal efflux of cyclic AMP that was mitigated by somatostatin, added at 6 x 10(-7) M to the serosal bath. Somatostatin inhibited secretin- and prostaglandin E1-induced Isc, but was ineffective in tissues stimulated with 8-Br-cyclic AMP. It partly reverted the effects of secretin on JmsHCO3 and JsmHCO3, but had no effects in untreated tissues. Our data indicate that secretin converts HCO3-secretion from an electroneutral into an electrogenic process and blocks part of NaCl absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

UI	MeSH Term	Description	Entries
D008297	Male		Males
D004573	Electrolytes	Substances that dissociate into two or more ions, to some extent, in water. Solutions of electrolytes thus conduct an electric current and can be decomposed by it (ELECTROLYSIS). (Grant & Hackh's Chemical Dictionary, 5th ed)	Electrolyte
D004848	Epithelium	The layers of EPITHELIAL CELLS which cover the inner and outer surfaces of the cutaneous, mucus, and serous tissues and glands of the body.	Mesothelium,Epithelial Tissue,Mesothelial Tissue,Epithelial Tissues,Mesothelial Tissues,Tissue, Epithelial,Tissue, Mesothelial,Tissues, Epithelial,Tissues, Mesothelial
D005704	Gallbladder	A storage reservoir for BILE secretion. Gallbladder allows the delivery of bile acids at a high concentration and in a controlled manner, via the CYSTIC DUCT to the DUODENUM, for degradation of dietary lipid.	Gallbladders
D006168	Guinea Pigs	A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.	Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
D000242	Cyclic AMP	An adenine nucleotide containing one phosphate group which is esterified to both the 3'- and 5'-positions of the sugar moiety. It is a second messenger and a key intracellular regulator, functioning as a mediator of activity for a number of hormones, including epinephrine, glucagon, and ACTH.	Adenosine Cyclic 3',5'-Monophosphate,Adenosine Cyclic 3,5 Monophosphate,Adenosine Cyclic Monophosphate,Adenosine Cyclic-3',5'-Monophosphate,Cyclic AMP, (R)-Isomer,Cyclic AMP, Disodium Salt,Cyclic AMP, Monoammonium Salt,Cyclic AMP, Monopotassium Salt,Cyclic AMP, Monosodium Salt,Cyclic AMP, Sodium Salt,3',5'-Monophosphate, Adenosine Cyclic,AMP, Cyclic,Adenosine Cyclic 3',5' Monophosphate,Cyclic 3',5'-Monophosphate, Adenosine,Cyclic Monophosphate, Adenosine,Cyclic-3',5'-Monophosphate, Adenosine,Monophosphate, Adenosine Cyclic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012633	Secretin	A peptide hormone of about 27 amino acids from the duodenal mucosa that activates pancreatic secretion and lowers the blood sugar level. (USAN and the USP Dictionary of Drug Names, 1994, p597)	Secrepan,Secretin Citrate, Pig,Secretin Maleate, Pig,Secretin Pentacetate, Pig,Secretin Sulfate, Pig,Secretin, Pig,Secretin-KABI,Pig Secretin,Pig Secretin Citrate,Pig Secretin Maleate,Pig Secretin Pentacetate,Pig Secretin Sulfate,Secretin KABI,SecretinKABI
D013004	Somatostatin	A 14-amino acid peptide named for its ability to inhibit pituitary GROWTH HORMONE release, also called somatotropin release-inhibiting factor. It is expressed in the central and peripheral nervous systems, the gut, and other organs. SRIF can also inhibit the release of THYROID-STIMULATING HORMONE; PROLACTIN; INSULIN; and GLUCAGON besides acting as a neurotransmitter and neuromodulator. In a number of species including humans, there is an additional form of somatostatin, SRIF-28 with a 14-amino acid extension at the N-terminal.	Cyclic Somatostatin,Somatostatin-14,Somatotropin Release-Inhibiting Hormone,SRIH-14,Somatofalk,Somatostatin, Cyclic,Somatotropin Release-Inhibiting Factor,Stilamin,Somatostatin 14,Somatotropin Release Inhibiting Factor,Somatotropin Release Inhibiting Hormone