• The Korean Journal of Physiology
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• v.24 no.1
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• pp.39-49
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• 1990

It has been reported that bombesin induces contraction of the smooth muscle of the gastrointestinal tract. Thus, the present investigation was undertaken to see an influence of bombesin on electrical activity of the gastric smooth muscle, since electrical activity is associated with contractile activity in the smooth muscle of the stomach. Smooth muscle strips $(5\;{\times}\;1.5\;cm)$ that included the corpus and antrum were prepared from the ventral and dorsal portion of the feline stomach along the greater curvature. Circular muscle strips $(1\;{\times}\;0.3\;cm)$ of the corpus were also obtained. Electrical activity of the corpus and antrum of the muscle strip was monophasically recorded by using Ag-AgCl capillary electrodes placed on the circular muscle layer. Contractile activity of the circular muscle strip was also recorded. The recordings were performed in Krebs-Ringer solution that was continuously aerated with $O_{2}$ containing 5% $Co_{2}$, and kept at $36^{\circ}C$. Dose-related responses of electrical activity and contractility to bombesin was studied after frequency of slow waves and contraction of each strip reached to a steady state. An action of $D-leu^{13}-{\psi}\;(CH_{2}NH)-D-leu^{14}-bombesin,\;D-pro^{2}-D-trp^{7,9}-substance\;P$, tetrodotoxin, hexamethonium, atropine, phentolamine or propranolol on the effect of bombesin was also observed. 1) Bombesin increased frequency of slow waves and contractions dose-dependently at concentrations from $10^{-9}\;M\;to\;3\;{\times}\;10^{-8}\;M$. 2) The bombesin analogue at a concentration of $3\;{\times}\;10^{-7}\;M$ antagonized the effect of bombesin on frequency of slow waves. 3) The effect of bombesin on frequency of slow waves was inhibited by tetrodotoxin $(10^{-6}\;M)$ and hexamethonium $(10^{-3}\;M)$ but unaffected by atropine $(10^{-6}\;M)$, phentolamine $(10^{-5}\;M)$ and propranolol $(10^{-5}\;M)$. 4) The effect of bombesin on frequency of slow waves was blocked by the substance P analogue at a concentration of $10^{-5}\;M$. 5) Substance P at a concentration of $10^{-5}\;M$ failed to change frequency of slow waves. It is concluded from the above results that bombesin increases the frequency of slow waves as well as contractions of the smooth muscle strip from the feline stomach, and the effect of bombesin might be mediated by non-cholinergic or non-adrenergic mechanism at neuromuscular junction. However, enteric nerves that have substance P as a neurotransmitter do not appear to participate in the action of bombesin on frequency of slow waves.

• The Korean Journal of Physiology and Pharmacology
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• v.2 no.5
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• pp.637-644
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• 1998

Previously, we have isolated authentic bombesin and another bombesin like peptide named bombesin like immunoreactivity (BLI)-K2 from the skin of Korean fire-bellied toad, Bombina orientalis. In the present study, we have newly purified three heterogeneous forms of BLI named BLI-K3, BLI-K4, and BLI-K5 from side fractions obtained in previous isolation of bombesin like peptide. The BLIs were separated into five peaks on a column of $C_{18}$ preparative HPLC. Among them, three minor peaks containing BLI-K3, K4, and K5 were purified by means of sequential chromatography on the columns of SP cation exchange HPLC and $C_{18}$ reverse phase HPLC. The purified BLI-K3 and K4 showed high binding affinity to an anti-bombesin serum (LBE 2G-2) with binding potency of 72 and 95%, respectively, relative to that of bombesin. However, they did not possess any distinctive biological activity of bombesin like peptide. On the contrary, the biological activity of BLI-K5 was similar to that of bombesin but its binding affinity to an anti-bombesin serum was low. The results indicate that three heterogeneous forms of BLI were coexpressed with bombesin and BLI-K2 in the skin of B. orientalis. All forms of the purified BLI in the present study were immunologically active but only BLI-K5 possessed the distinctive biological activity of bombesin like peptide.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.91-97
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• 1994

In order to produce a specific bombesin antiserum far very sensitive radioimmunoassay, synthetic $[lys^3]-bombesin$ conjugated to bovine serum albumin was subcutaneously injected into guinea pigs. The conjugation was performed using either carbodiimide or gIutaraldehyde as a coupling agent. The antisera were characterized by analysis of Scatchard and Sips plots. The antiserum LBE 2G/2 raised by repeat injection of the immunogen conjugated with carbodiimide showed the titer of 1 : 188,000, very low cross-reactivity to bombesin-like peptides except bombesin, with high affinity constant $(1.64{\times}10^{11}\;M^{-1})$ and high heterogeneity index (0.91). The antiserum LBG 1G/2 produced by repeat injection of the immunogen conjugated with glutaraldehyde possessed the titer of 1 : 43,000, high cross-reactivity to some bombesin-like peptides, high affinity constant $(1.19{\times}10^{11}\;M^{-1})$ and high heterogeneity index (0.79). These results indicate that the antiserum LBE 2G/2 is specific only to bombesin and that the antiserum LBG IG/2 binds to some bombesin-like peptides such as alytesin, gastrin releasing peptide and neuromedin C. The antiserum LBE 2G/2 is sufficient for the very sensitive radioimmunoassay of bombesin.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.8 no.2
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• pp.129-137
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• 2022

Bombesin has a high binding affinity to gastrin-releasing peptide receptor (GRPR) and can be used as a targeting ligand in GRPR-related cancers. Because GRPR is overexpressed in prostate cancer, bombesin analogues have been investigated extensively for diagnosis and treatment of prostate cancer. In nuclear medicine, bombesin derivatives labeled with radiometals such as ^55/57Co, ⁶⁴Cu, ⁶⁸Ga, ^99mTc, and ¹⁷⁷Lu or radiohalogen such as ¹³¹I and ²¹¹At were developed as markers for early detection of tumors and theragnostic tool for cancer treatment. This review focuses on the introduction of bombesin-based radiopharmaceuticals that are studied in pre-clinical or clinical research.

• The Journal of Korean Physical Therapy
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• v.11 no.2
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• pp.115-122
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• 1999

This experiment was carried out to investigate the bombesin immunoreactivity in suprachiasmatic nucleus in rat and Mongolian gerbil hypothalamus after colchicine treatment and analyze the morphological difference between rat and Mongolian gerbil which is focused for experimental animal model of neuronal and circulatory diseases. The results were as followings. 1. The shape of suprachiasmatic nucleus was triangle in rat, but oval or kidney-shape in Mongolian gerbil 2. The suprachiasmatic nucleus devided into ventrolateral portion and dorsomedial portion in rat, but dorsolateral portion and ventromedial portion or superior portion and inferior portion in Mongolian gerbil. 3. The area of suprachiasmatic nucleus of rat was greater than one of Mongolian gerbil. 4. The bombesin immunoreactivity showed after colcichine treatment in rat and Mogolian gerbil suprachiasmatic nucleus. 5. The bombesin immunoreactivity was stronger in ventrolateral portion than in dorsomedial portion of suprachiasmatic nucleus in rat, but in ventromedial or inferior portion than in dorsolateral or superior portion of suprachiasmatic nucleus in Mongolian gerbil. 6. The bombesin immunoreactivity showed at the oval, ellipsoid or triangular neurons and varicose nerve terminals in ventrorateral portion of rat, and only nerve terminals in dorsomedial portion of rat suprachiasmatic nucleus. But the bombesin immunoreativity didn't show at neurons of Mongolian gerbil suprachiasmatic nucleus.

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.363-375
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• 1990

The present investigation was performed to purify bombesin-like immunoreactivity (BBS-LI) from the skin of frogs, B. orientalis inhabiting Korea. For extraction of BBS-LI, the fresh skin of 360 g from frogs was immersed in 1,800 ml of 100% methanol and then kept at $4^{\circ}C$ for 5 days. BBS-LI was partially purified by liquid chromatography using an alkaline alumina column followed by a Sephadex G-10 column. BBS-LI was further purified by using sequential HPLC of reversed phase C18 preparation, gel permeation, SP-ion exchange and reversed phase C18 analysis. BBS-LI in fractions of each step was monitored by radioimmunoassay for which bombesin antiserum with a titer of 1 : 188,800 was raised in a guinea pig. Eventually, two different BBS-LI were successfully purified and each BBS-LI showed the following character. 1) BBS-LI was well separated into two peaks in SP-ion exchange HPLC. One (BBS-LI-K1) bound to the column while the other (BBS-LI-K2) did not. 2) BBS-LI-K1, 73.8% of total BBS-LI, was not differentiated from synthetic bombesin in reversed phase C18 analytical and gel permeation HPLC. 3) BBS-LI-K2, 26.2% of total BBS-LI, eluted later than synthetic bombesin in reversed phase C18 analytical HPLC, but it eluted with a retention time identical to that of synthetic bombesin in gel permeation HPLC. 4) The two forms of BBS-LI and synthetic bombesin identically stimulated gastrin release and pancreatic exocrine secretion including volume, protein output and amylase output in anesthetized rats. It is concluded from the above results that the skin of B. orientalis contains two different forms of BBS-LI which are very identical to bombesin immunologically and biologically. In comparison with synthetic bombesin containing 14 amino acid residues, the major form shows quite similar pattern in all HPLC used in the present study, but the minor form exhibits quite different pattern in SP-ion exchange and reversed phase C18 analytical HPLG.

• The Korean Journal of Physiology
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• v.28 no.1
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• pp.105-111
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• 1994

The present study was carried out to determine the effects of intracisternal administration of three doses of bombesin $(0.001,\;0.01\;and\;0.1\;{\mu}g)$ on afferent somatosensory transmission in single neurons of the spinal trigeminal nucleus of anesthetized rats. Lower doses $(0.001\;{\mu}g)$ of bombegin did not change the afferent sensory transmission. Medium doses $(0.01\;{\mu}g)$ of bombesin significantly (p p<0.01) facilitated afferent sensory transmission in the 6 to 30 min post-drug period, but higher doses $(0.1\;{\mu}g)$ inhibited responsiveness of spinal trigeminal neurons in the 16 to 35 min post-drug period. The results indicate that endogenous bombesin-like peptide present in the spinal trigeminal nucleus may participate in the processing of the somatosensory information arising from the face.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1033-1037
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• 1999

This study was carried out to compare the distribution pattern of the bombesin immunoreactive neurons of the hypothalamic nucleus in the rat and Mongolian gerbil. The bombesin immunoreactive neurons in the rat were located in the dorsal part of the dorsomedial hypothalamic nucleus, but in the Mongolian gerbil in the compact part of dorsomedial hypothalamic nucleus. From this results, we could get an evidence that there were some differences in the distribution of peptide between rat and Mongolian gerbil.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.127-134
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• 2013

Bombesin receptors are overexpressed in many kinds of human tumors. In particular, the gastrin releasing peptide receptor (GRPR) which is also called bombesin receptor subtype 2, has been identified in prostate cancer. In the present study, we developed a bombesin antagonist-based $^{177}Lu$-labeled peptide, $^{177}Lu$-DOTA-$Ala(SO_3H)$-Aminooctanoyl-Gln-Trp-Ala-Val-N methyl Gly-His-Statine-Leu-$NH_2$ (DOTA-sBBNA). DOTA-sBBNA was prepared using a solid phase synthesis method. It was labeled with $^{177}Lu$ by a high radiolabeling yield (>98%), and its Log P value was -2.05. The radiolabeled peptide was highly stable in serum incubation at $37^{\circ}C$ for 48 hr. A competitive displacement of $^{125}I-[Tyr^4]$-Bombesin on the PC-3 human prostate carcinoma cells revealed that the $IC_{50}$ value of the peptide was 6.76 nM indicating a highly nanomolar binding affinity for GRPR. These results suggest that $^{177}Lu$-DOTA-sBBNA can be a potential candidate for targeting prostate cancer, and further studies to evaluate its biological characteristics are needed.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.195-196
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• 1989