In vivo investigations of neurotensin receptors in adipocytes, hepatocytes and enterocytes of rat.
BACKGROUND
Atherosclerotic vascular disease is currently the biggest threat and the highest cause of death worldwide, approaching almost 60%.The development of atherosclerosis is affected by ecological factors associated with industry and pollution of the environment. Neurotensin (NT) is a peptide acting via 3 kinds of neurotensin receptors (NTR) localized in target tissues. In several studies, the presence of its receptors has been shown in chicken liver, and the influence of NT on the metabolism of this organ was confirmed (glycogenolysis stimulation through sympathetic nervous system, enterohepatic circulation of bile acids, metabolism of lipoproteins).


METHODS
Healthy male WISTAR rats weighing 300}30 grams, were used for the experiments. The animals were divided into 4 groups: 1) control group, to which 0.9% NaCl was administrated (i.p.); 2) the second group was given levocabastine 1mg/kg i.p.; 3) the third group received SR 48692 0.4 mg/; 4) the fourth group was given NT analog [D-Trp 11]-neurotensin 15 nM/kg. Plasmatic membranes of liver, small intestine and adipose tissue were prepared according to the method of Havrankova. Analysis of results obtained in the investigation of NT receptors was performed using the Scatchard method from LIGAND-Pc, v. 3.1 software.


RESULTS
The investigation of antigenity of I125NT showed proper antigen-antibody reaction. No binding of the I125NT with plasmatic membranes of adipocytes or enterocytes was observed. Unspecific binding of I125NT with 10 μmol/L of free NT was observed in the plasmatic membranes of hepatocytes.


CONCLUSIONS
The presence of NT receptors only in the membranes of hepatocytes may suggest their role in the regulation of lipid metabolism via receptor – ligand way.
Department of Physiology, University of Medical Sciences, Poznań, Poland. drpiatek@interia.eu
Jacek
J
Piątek
Paweł
P
Maćkowiak
Hanna
H
Krauss
Dorota
D
Nowak
Paweł
P
Bogdański
D017667:Adipocytes / Q000378:metabolism; D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D000937:Antigen-Antibody Reactions; D002462:Cell Membrane / Q000378:metabolism; D020895:Enterocytes / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism; D039563:Histamine H1 Antagonists, Non-Sedating / Q000494:pharmacology*; D007421:Intestine, Small / Q000378:metabolism; D007457:Iodine Radioisotopes / Q000737:chemistry; D007553:Isotope Labeling / Q000662:veterinary; D008099:Liver / Q000378:metabolism; D008297:Male; D009496:Neurotensin / Q000031:analogs & derivatives* / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology*; D011720:Pyrazoles / Q000494:pharmacology*; D011804:Quinolines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018028:Receptors, Neurotensin / Q000037:antagonists & inhibitors* / Q000378:metabolism*
D039563:Histamine H1 Antagonists, Non-Sedating; D007457:Iodine Radioisotopes; D010880:Piperidines; D011720:Pyrazoles; D011804:Quinolines; D018028:Receptors, Neurotensin; C079087:SR 48692; D009496:Neurotensin; C024309:neurotensin, Trp(11)-; C047340:levocabastine