Disease relevance of Litorine

• Four dogs with chronic gastric fistulas were give intravenous bombesin nonapeptide (B9), ranatensin, and litorin by constant infusion for 90 min at 1.2 micrograms x kg-1 on separate days [1].
• Litorine is active in vitro against Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Microsporum canis [2].

Psychiatry related information on Litorine

• Ranatensin and litorin, like bombesin, proved to inhibit drinking and feeding behavior [3].
• Litorin shares with bombesin structural features and pharmacological actions that include the suppression of food intake in a manner that mimics natural satiation [4].
• However, the volume of food intake in the hour following 24 h food deprivation was lower in rats immunized with conjugated litorin than in the control groups [5].

High impact information on Litorine

• Bombesin and litorin may provide useful model peptides for studies on the mechanism(s) by which extracellular ligands control cell proliferation [6].
• For Bn receptor agonists the relative potencies were: NMB (1.7 nM) approximately equal to litorin (3 nM) greater than ranatensin (8 nM) greater than Bn (19 nM) greater than neuromedin C (NMC) (210 nM) greater than GRP (500 nM) [7].
• The BBS analogs ranatensin, litorin, and [Tyr4]BBS, each at a concentration of 100 nM, caused the same stimulation of PRL release as maximal concentrations of BBS itself [8].
• 2 The order of potency of agonists was determined with several naturally occurring peptides of the bombesin series, namely bombesin (BBS), litorin (Lit), neuromedin B (NMB), the gastrin-releasing peptide (GRP 18-27), neuromedin C (NMC) and with some bombesin fragments [9].
• A litorin-like peptide, with high affinity for this kind of receptor, has already been described in mammalian spinal cord and named neuromedin B [10].

Biological context of Litorine

• For testing on food intake in fasted rats the peptides were injected intraperitoneally (i.p.) and intracerebroventricularly (i.c.v.) and their activity compared with that of bombesin (BN) and litorin (LIT) [11].
• While an approximate 100-fold lower binding affinity was displayed by the binding site for neuromedin B (Ki; 6.15 +/- 28.2 nM), litorin was highly effective in displacing radiolabeled BBS binding (Ki; 1.469 +/- 0.427 nM) [12].
• Parallel bioassay of litorin and Glu(OMe)2-litorin on smooth muscle preparations and blood pressure [13].
• Litorin and litorin-albumin conjugate as effective regulators of body temperature in rats [5].
• These results suggest that litorin is involved in the physiological regulation of thermal homeostasis [5].

Anatomical context of Litorine

• 2 Litorin proved to be more potent than bombesin on isolated smooth muscle preparations and on the urinary bladder in situ [14].
• 5 In its effects on the myo-electric activity of the dog duodenum (inhibition of spikes and increase in frequency of pacesetter potentials leading to the appearance of a sequence of slow and small potentials) litorin possessed approximately 50 to 70% of the activity of bombesin [14].
• These findings suggest that litorin acts on the hypothalamus to inhibit TRH release, and that its effects are modified by amines of the central nervous system [15].
• 1. Low levels of bombesin-like immunoreactivity (less than 1.10 pmol/g tissue), eluting at the same position as synthetic bombesin and litorin, have been measured in muscle and mucosa of the gastrointestinal canal of the cod, Gadus morhua [16].
• In dispersed acini prepared from guinea pig pancreas, peptides isolated from amphibian skin (caerulein, bombesin, litorin, and physalaemin) as well as eledoisin, a peptide isolated from the posterior salivary gland of a Mediterranean octopod, caused a significant increase in amylase release [17].

Gene context of Litorine

• B9 released significantly more PP than either litorin of ranatensin (P less than 0.01) [1].
• Bombesin caused significantly greater release of gastrin than a meal, litorin or ranatensin (P less than 0.01) [1].
• 3 Gastrin release and acid secretion produced by litorin was more rapid in onset but less intense and less sustained than that elicited by bombesin [14].
• 4 Gall bladder contraction stimulated by litorin was probably caused by a double action of the peptide, directly on the bladder smooth muscle, and indirectly by cholecystokinin release [14].
• The hypothalamic immunoreactive TRH (ir-TRH) content increased significantly after litorin injection, whereas its plasma concentration tended to decrease, but not significantly [15].

Analytical, diagnostic and therapeutic context of Litorine

• Parallel bioassay of bombesin and litorin, a bombesin-like peptide from the skin of Litoria aurea [14].
• In spite of the marked structural analogy between bombesin and litorin, their EEG effects differ [18].
• Intraperitoneal injection of the bombesin-like peptide litorin (0.5 ml of a 10(-5) M solution) led to a short-lived decrease in the body temperature (maximum of 0.9 degrees C) of laboratory rats [5].

References