Preoperative bombesin administration can protect the rat small bowel allograft from ischemic reperfusion injury

Prenatal administration of neuropeptide bombesin promotes lung development in a rat model of nitrofen-induced congenital diaphragmatic hernia

BACKGROUND/PURPOSE

Fetal medical treatment to improve lung hypoplasia in congenital diaphragmatic hernia (CDH) has yet to be established. The neuropeptide bombesin (BBS) might play an important role in lung development. The present study aims to determine whether prenatally administered BBS could be useful to promote fetal lung development in a rat model of nitrofen-induced CDH.

METHODS

Pregnant rats were administered with nitrofen (100mg) on gestation day 9.5 (E9.5). BBS (50mg/kg/day) was then daily infused intraperitoneally from E14, and fetal lungs were harvested on E21. The expression of PCNA was assessed by both immunohistochemical staining and RT-PCR to determine the amount of cell proliferation. Lung maturity was assessed as the expression of TTF-1, a marker of alveolar epithelial cell type II.

RESULTS

The lung-body-weight ratio was significantly increased in CDH/BBS(+) compared with CDH/BBS(-) (p<0.05). The number of cells stained positive for PCNA and TTF-1 was significantly decreased in CDH/BBS(+) compared with CDH/BBS(-) (p<0.01). The TTF-1 mRNA expression levels were significantly decreased in CDH/BBS(+) compared with CDH/BBS(-) (p<0.05).

CONCLUSIONS

Prenatally administered BBS promotes lung development in a rat model of nitrofen-induced CDH. Neuropeptide BBS could help to rescue lung hypoplasia in fetal CDH.

Bombesin can minimize impairments of interstitial cells of Cajal induced by FK506 in small bowel transplantation

PURPOSE

Interstitial cells of Cajal (ICC) are known as intestinal pacemaker cells and express c-kit on their membrane. Previously, we reported that FK506 had neurotoxicity to enteric ganglia, and bombesin (BBS) preserved them against FK506. The aim of this study was to investigate whether ICC was impaired by FK506 and whether ICC was preserved by BBS against FK506.

METHODS

Twelve rats underwent allogeneic SBTx heterotopically and were divided into 2 groups as follows: group A underwent SBTx with FK506 and group B with FK506/BBS. All rats were administered FK506 daily. Either BBS or normal saline was infused continuously from day 14 to 28. Analysis of ICC was performed immunohistochemically with c-kit. Interstitial cells of Cajal were evaluated by counting the number of c-kit-positive clusters in each graft.

RESULTS

The expression of c-kit accumulated around 60% of PGP9.5-positive enteric ganglia. The number of c-kit-positive clusters in group A was 22.3 +/- 5.5 clusters per cross section (C/CS) and that in group B was 36.3 +/- 5.1 C/CS. Interstitial cells of Cajal were well preserved in group B. There was a significant difference between groups A and B (P <.001).

CONCLUSION

Interstitial cells of Cajal were impaired by FK506 in allografts, and BBS could minimize the impairment of ICC against FK506.

International Union of Pharmacology. LXVIII. Mammalian bombesin receptors: nomenclature, distribution, pharmacology, signaling, and functions in normal and disease states

The mammalian bombesin receptor family comprises three G protein-coupled heptahelical receptors: the neuromedin B (NMB) receptor (BB(1)), the gastrin-releasing peptide (GRP) receptor (BB(2)), and the orphan receptor bombesin receptor subtype 3 (BRS-3) (BB(3)). Each receptor is widely distributed, especially in the gastrointestinal (GI) tract and central nervous system (CNS), and the receptors have a large range of effects in both normal physiology and pathophysiological conditions. The mammalian bombesin peptides, GRP and NMB, demonstrate a broad spectrum of pharmacological/biological responses. GRP stimulates smooth muscle contraction and GI motility, release of numerous GI hormones/neurotransmitters, and secretion and/or hormone release from the pancreas, stomach, colon, and numerous endocrine organs and has potent effects on immune cells, potent growth effects on both normal tissues and tumors, potent CNS effects, including regulation of circadian rhythm, thermoregulation; anxiety/fear responses, food intake, and numerous CNS effects on the GI tract as well as the spinal transmission of chronic pruritus. NMB causes contraction of smooth muscle, has growth effects in various tissues, has CNS effects, including effects on feeding and thermoregulation, regulates thyroid-stimulating hormone release, stimulates various CNS neurons, has behavioral effects, and has effects on spinal sensory transmission. GRP, and to a lesser extent NMB, affects growth and/or differentiation of various human tumors, including colon, prostate, lung, and some gynecologic cancers. Knockout studies show that BB(3) has important effects in energy balance, glucose homeostasis, control of body weight, lung development and response to injury, tumor growth, and perhaps GI motility. This review summarizes advances in our understanding of the biology/pharmacology of these receptors, including their classification, structure, pharmacology, physiology, and role in pathophysiological conditions.

Bombesin can rescue the enteric ganglia from FK506 neurotoxicity on small bowel transplantation

BACKGROUND/PURPOSE

FK506 has been reported to have neurotoxic effects. The aim of this study was to investigate whether FK506 causes neurotoxic effects on the transplanted graft enteric ganglia (TGEG) and whether bombesin (BBS) can prevent such atrophy.

METHODS

Thirty rats heterotopically underwent small bowel transplantation and were divided into 5 groups as follows: group A, syngraft (SYN) alone; group B, SYN with FK506; group C, SYN with FK506 and BBS; group D allograft with FK506; group E, allograft with FK506 and BBS. From postoperative days 14 to 28, either BBS or normal saline was administered continuously. All recipients except for group A received FK506 daily. The ganglionic count was obtained by counting the number of protein gene product 9.5 immunohistochemically stained ganglia in the cross sections of each graft.

RESULTS

The number of TGEG in groups A, B, and C was 69.7 +/- 6.0, 51.5 +/- 7.7, and 84.8 +/- 10.2 ganglia per cross section, respectively. There was a significant difference between each group (P < .001). The number of TGEG in groups D and E was 44.6 +/- 7.5 and 65.1 +/- 9.5 ganglia per cross section, respectively. There was a significant difference between the 2 groups (P < .001).

CONCLUSIONS

FK506 causes severe neurotoxicity in transplanted grafts, and BBS protects graft enteric ganglia against the neurotoxic effects of FK506.