PubMed Health⌕ Search

Biomedical subjects

S I Churkina

Publications and source records attributed to S I Churkina.

15 recordsLinked to original sources

[The effect of bombesin and its analogs on the secretion of gastric juice and its content of pepsin and hydrochloric acid].

I.V. Infusion of bombesine after eating raw meat inhibited for 30-60 min the secretion of gastric juice and hydrochloric acid in dogs. Within 90-120 min of simultaneous infusion of pentagastrin and bombesine, the amount of secreted juice and its acidity decreased and then the secretion of gastric parietal cells increased. Simultaneous infusion of histamine and bombesine increased the response of gastric parietal cells during the whole experiment as compared with the histamine effect alone. Microapplication of bombesine into cerebral structures also decreased the secretory response of the parietal cells.

Animals↗

[Amphibian bombesin and its analog alytesin].

A convenient route of synthesis of amphibian bombesin and bombesin-like peptide alytesin was found. These tetradecapeptides were obtained by assembling the 1-5 and 6-14 fragments by means of DCC-HONB or mixed anhydrides methods. Structure of the tetradecapeptides was confirmed by high resolution NMR spectroscopy data. The bombesin and alytesin synthesized potently decrease body temperature and stimulate pancreatic juice secretion.

Amino Acid Sequence↗

[Active analog of the inactive "sleep peptide"].

Delta Sleep-Inducing Peptide (DSIP) was not previously found to possess hypnogenic properties. Its analogue (D-TrpI)DSIP was more stable against aminopeptidases. Its intracerebrovascular administration in doses of 0.7, 7 and 70 micrograms/kg body weight induced a significant increase in slow wave sleep (by 40%; p less than 0.01, U-test) and rectal temperature elevation (by 0.9 degrees C; p less than 0.01) within the following 3 day-light hours, as compared to the control rabbits treated with physiologic saline. Intravenous injections of the DSIP analogue increased slow wave sleep by 25% in a narrow dose range (30-70 micrograms/kg).

Animals↗

[Physiological effects of bombesin].

Central or peripheral administration of bombesin--tetradecapeptide obtained from amphibian skin, acted upon the nervous system, behaviour, thermoregulation and gastro-intestinal tract. New experimental data on synthesis, immunohistochemistry and physiological effects of bombesin and related peptides are presented.

Animals↗

[Effect of bombesin, its various fragments and their analogs on thermoregulation in rabbits].

Out of synthetic tetradecapeptide bombesin, its fragments C-terminal nonapeptide and N-terminal pentapeptide and their analogues ( Val7 , D- Ala11 ), ( Ala7 , D- Ala11 ), (Leu7, D- Ala11 ) and ( Pro6 , Gly7 , D- Ala11 ), the first two, being injected into the lateral ventricle of the brain in rabbits, affected the body temperature in cold environment (+ 10 degrees C). The analogues exerted a lesser effect on the body temperature. N-terminal pentapeptide was ineffective both in cold (+ 10 degrees C) and warm (+ 30 degrees C) environment.

Animals↗

[The effect of regulatory peptides on water absorption in the large intestine of the frog].

Preparation of isolated large intestine of the frog was filled with Ringer's solution diluted with distilled water (1:5) and was placed into the glass with normal Ringer's solution. The preparation was weighed within every 30 min and the osmotic permeability was determined for water of the mucous and serous layers of the intestine. Then one of the peptides was added to Ringer's solution and the experiment continued. It is stated that bombesin, neurotensin, encephalins, substance P, somatostatin, pituitrin are able to change liquid absorption from the large intestine cavity when the concentration of Ringer's solution in the cavity and from its serous surface is the same. Bombesin and neurotensin inhibited while encephalins stimulated liquid absorption and these effects depended on the transport of ions. Liquid absorption by the osmotic gradient decreased using bombesin, substance P and increased using somatostatin. More complex peptide-peptide relations are observed if using pituitrin and other peptides. cAMP is shown to participate in bombesin effects.

Animals↗