Biomaterial Database

Pancreatic receptors: initial feasibility studies with a targeted contrast agent for MR imaging. 1994

P Reimer, and R Weissleder, and T Shen, and W T Knoefel, and T J Brady

Department of Radiology, MGH-NMR Center, Massachusetts General Hospital, Boston.

OBJECTIVE To evaluate cholecystokinin (CCK) as a target-specific vector for magnetic resonance (MR) receptor imaging of rat pancreas. METHODS Monocrystalline iron oxide (MION) was labeled with CCK by noncovalent attachment. Receptor specificity of the conjugate was determined with competitive binding studies. Pharmacologic determinations were blood half-lives, biodistribution, time responses, dose responses, and limited toxicity. RESULTS Specific cell binding of MION-20-CCK was saturable and inhibitable by a CCK antagonist. Blood half-life of MION-20-CCK was 20 minutes, which was shorter than that of unlabeled MION. Biodistribution studies showed a statistically significant decrease in relaxation times in pancreatic tissues from 42.7 msec +/- 2.0 to 33.8 msec +/- 1.4 (P < or = .05) but not in tumor after administration of MION-20-CCK. The half-life of MION-20-CCK in the pancreas was 3 weeks; no signs of toxicity were shown at the level tested. CONCLUSIONS Target-specific MR imaging of pancreatic receptors is feasible. Additional studies are necessary to perfect binding strategies, optimize preparations, and scale up synthesis for imaging in other species.

UI	MeSH Term	Description	Entries
D007501	Iron	A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.	Iron-56,Iron 56
D008279	Magnetic Resonance Imaging	Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.	Chemical Shift Imaging,MR Tomography,MRI Scans,MRI, Functional,Magnetic Resonance Image,Magnetic Resonance Imaging, Functional,Magnetization Transfer Contrast Imaging,NMR Imaging,NMR Tomography,Tomography, NMR,Tomography, Proton Spin,fMRI,Functional Magnetic Resonance Imaging,Imaging, Chemical Shift,Proton Spin Tomography,Spin Echo Imaging,Steady-State Free Precession MRI,Tomography, MR,Zeugmatography,Chemical Shift Imagings,Echo Imaging, Spin,Echo Imagings, Spin,Functional MRI,Functional MRIs,Image, Magnetic Resonance,Imaging, Magnetic Resonance,Imaging, NMR,Imaging, Spin Echo,Imagings, Chemical Shift,Imagings, Spin Echo,MRI Scan,MRIs, Functional,Magnetic Resonance Images,Resonance Image, Magnetic,Scan, MRI,Scans, MRI,Shift Imaging, Chemical,Shift Imagings, Chemical,Spin Echo Imagings,Steady State Free Precession MRI
D008297	Male		Males
D008325	Mammary Neoplasms, Experimental	Experimentally induced mammary neoplasms in animals to provide a model for studying human BREAST NEOPLASMS.	Experimental Mammary Neoplasms,Neoplasms, Experimental Mammary,Experimental Mammary Neoplasm,Mammary Neoplasm, Experimental,Neoplasm, Experimental Mammary
D009368	Neoplasm Transplantation	Experimental transplantation of neoplasms in laboratory animals for research purposes.	Transplantation, Neoplasm,Neoplasm Transplantations,Transplantations, Neoplasm
D010087	Oxides	Binary compounds of oxygen containing the anion O(2-). The anion combines with metals to form alkaline oxides and non-metals to form acidic oxides.	Oxide
D010179	Pancreas	A nodular organ in the ABDOMEN that contains a mixture of ENDOCRINE GLANDS and EXOCRINE GLANDS. The small endocrine portion consists of the ISLETS OF LANGERHANS secreting a number of hormones into the blood stream. The large exocrine portion (EXOCRINE PANCREAS) is a compound acinar gland that secretes several digestive enzymes into the pancreatic ductal system that empties into the DUODENUM.
D010195	Pancreatitis	INFLAMMATION of the PANCREAS. Pancreatitis is classified as acute unless there are computed tomographic or endoscopic retrograde cholangiopancreatographic findings of CHRONIC PANCREATITIS (International Symposium on Acute Pancreatitis, Atlanta, 1992). The two most common forms of acute pancreatitis are ALCOHOLIC PANCREATITIS and gallstone pancreatitis.	Acute Edematous Pancreatitis,Acute Pancreatitis,Pancreatic Parenchyma with Edema,Pancreatic Parenchymal Edema,Pancreatitis, Acute,Pancreatitis, Acute Edematous,Peripancreatic Fat Necrosis,Acute Edematous Pancreatitides,Acute Pancreatitides,Edema, Pancreatic Parenchymal,Edematous Pancreatitides, Acute,Edematous Pancreatitis, Acute,Fat Necrosis, Peripancreatic,Necrosis, Peripancreatic Fat,Pancreatic Parenchymal Edemas,Pancreatitides, Acute,Pancreatitides, Acute Edematous,Parenchymal Edema, Pancreatic,Peripancreatic Fat Necroses
D011916	Rats, Inbred F344	An inbred strain of rat that is used for general BIOMEDICAL RESEARCH purposes.	Fischer Rats,Rats, Inbred CDF,Rats, Inbred Fischer 344,Rats, F344,Rats, Inbred Fisher 344,CDF Rat, Inbred,CDF Rats, Inbred,F344 Rat,F344 Rat, Inbred,F344 Rats,F344 Rats, Inbred,Inbred CDF Rat,Inbred CDF Rats,Inbred F344 Rat,Inbred F344 Rats,Rat, F344,Rat, Inbred CDF,Rat, Inbred F344,Rats, Fischer
D011949	Receptors, Cholecystokinin	Cell surface proteins that bind cholecystokinin (CCK) with high affinity and trigger intracellular changes influencing the behavior of cells. Cholecystokinin receptors are activated by GASTRIN as well as by CCK-4; CCK-8; and CCK-33. Activation of these receptors evokes secretion of AMYLASE by pancreatic acinar cells, acid and PEPSIN by stomach mucosal cells, and contraction of the PYLORUS and GALLBLADDER. The role of the widespread CCK receptors in the central nervous system is not well understood.	CCK Receptors,Caerulein Receptors,Cholecystokinin Octapeptide Receptors,Cholecystokinin Receptors,Pancreozymin Receptors,Receptors, CCK,Receptors, Caerulein,Receptors, Pancreozymin,Receptors, Sincalide,Sincalide Receptors,CCK Receptor,CCK-4 Receptors,CCK-8 Receptors,Cholecystokinin Receptor,Receptors, CCK-4,Receptors, CCK-8,Receptors, Cholecystokinin Octapeptide,CCK 4 Receptors,CCK 8 Receptors,Octapeptide Receptors, Cholecystokinin,Receptor, CCK,Receptor, Cholecystokinin,Receptors, CCK 4,Receptors, CCK 8