Biomaterial Database

The genetic advantage hypothesis in cystic fibrosis heterozygotes: a murine study. 1995

A W Cuthbert, and J Halstead, and R Ratcliff, and W H Colledge, and M J Evans

Department of Pharmacology, University of Cambridge, UK.

1. The delta F508 mutation of the cystic fibrosis (CF) gene is of high frequency in man (1 in 25) and in homozygotes causes cystic fibrosis. It is suggested that cystic fibrosis heterozygotes withstand secretory diarrhoea better than normal individuals and so are genetically advantaged. This hypothesis has been examined by measuring electrogenic chloride secretion in gut epithelia of normal and heterozygous CF mice. 2. Chloride secretory responses of normal and heterozygous colonic epithelia to forskolin, vasoactive intestinal polypeptide (VIP), isoprenaline, cholera toxin, heat-stable enterotoxin (STa), guanylin, carbachol and lysylbradykinin were examined. No significant differences in responses of tissues of the two genotypes were found. 3. Responses of normal and heterozygous ileal epithelia to forskolin and glucose were investigated. Heterozygous tissues responded as well as normal tissues. 4. Frusemide (furosemide) caused virtually identical inhibition of the chloride secretory responses to forskolin in colonic epithelia of both genotypes. 5. No evidence to support the genetic advantage hypothesis in ileal or colonic epithelia of the null CF mouse has been found, at least for acute responses. If the hypothesis is true then either (a) other non-cystic fibrosis transmembrane conductance regulator (non-CFTR) transport processes are involved, (b) prolonged exposure to secretagogues is required, or (c) delta F508 CFTR is responsible for the protective effect.

UI	MeSH Term	Description	Entries
D007082	Ileum	The distal and narrowest portion of the SMALL INTESTINE, between the JEJUNUM and the ILEOCECAL VALVE of the LARGE INTESTINE.
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D007609	Kallidin	A decapeptide bradykinin homolog cleaved from kininogen by kallikreins. It is a smooth-muscle stimulant and hypotensive agent that acts by vasodilatation.	Lysyl Bradykinin,Kallidin Tetraacetate,Kallidin, (D)-Isomer,Lys-Bradykinin,Lysine Bradykinin,N2-L-Lysylbradykinin,Bradykinin, Lysine,Bradykinin, Lysyl,Lys Bradykinin,N2 L Lysylbradykinin,Tetraacetate, Kallidin
D008817	Mice, Mutant Strains	Mice bearing mutant genes which are phenotypically expressed in the animals.	Mouse, Mutant Strain,Mutant Mouse Strain,Mutant Strain of Mouse,Mutant Strains of Mice,Mice Mutant Strain,Mice Mutant Strains,Mouse Mutant Strain,Mouse Mutant Strains,Mouse Strain, Mutant,Mouse Strains, Mutant,Mutant Mouse Strains,Mutant Strain Mouse,Mutant Strains Mice,Strain Mouse, Mutant,Strain, Mutant Mouse,Strains Mice, Mutant,Strains, Mutant Mouse
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002217	Carbachol	A slowly hydrolyzed CHOLINERGIC AGONIST that acts at both MUSCARINIC RECEPTORS and NICOTINIC RECEPTORS.	Carbamylcholine,Carbacholine,Carbamann,Carbamoylcholine,Carbastat,Carbocholine,Carboptic,Doryl,Isopto Carbachol,Jestryl,Miostat,Carbachol, Isopto
D002772	Cholera Toxin	An ENTEROTOXIN from VIBRIO CHOLERAE. It consists of two major protomers, the heavy (H) or A subunit and the B protomer which consists of 5 light (L) or B subunits. The catalytic A subunit is proteolytically cleaved into fragments A1 and A2. The A1 fragment is a MONO(ADP-RIBOSE) TRANSFERASE. The B protomer binds cholera toxin to intestinal epithelial cells and facilitates the uptake of the A1 fragment. The A1 catalyzed transfer of ADP-RIBOSE to the alpha subunits of heterotrimeric G PROTEINS activates the production of CYCLIC AMP. Increased levels of cyclic AMP are thought to modulate release of fluid and electrolytes from intestinal crypt cells.	Cholera Toxin A,Cholera Toxin B,Cholera Toxin Protomer A,Cholera Toxin Protomer B,Cholera Toxin Subunit A,Cholera Toxin Subunit B,Choleragen,Choleragenoid,Cholera Enterotoxin CT,Cholera Exotoxin,Cholera Toxin A Subunit,Cholera Toxin B Subunit,Procholeragenoid,Enterotoxin CT, Cholera,Exotoxin, Cholera,Toxin A, Cholera,Toxin B, Cholera,Toxin, Cholera
D003106	Colon	The segment of LARGE INTESTINE between the CECUM and the RECTUM. It includes the ASCENDING COLON; the TRANSVERSE COLON; the DESCENDING COLON; and the SIGMOID COLON.	Appendix Epiploica,Taenia Coli,Omental Appendices,Omental Appendix,Appendices, Omental,Appendix, Omental
D003550	Cystic Fibrosis	An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.	Mucoviscidosis,Cystic Fibrosis of Pancreas,Fibrocystic Disease of Pancreas,Pancreatic Cystic Fibrosis,Pulmonary Cystic Fibrosis,Cystic Fibrosis, Pancreatic,Cystic Fibrosis, Pulmonary,Fibrosis, Cystic,Pancreas Fibrocystic Disease,Pancreas Fibrocystic Diseases