Centrally administered adrenomedullin 2 activates hypothalamic oxytocin-secreting neurons, causing elevated plasma oxytocin level in rats

2005 ◽  
Vol 289 (5) ◽  
pp. E753-E761 ◽  
Author(s):  
Hirofumi Hashimoto ◽  
Susumu Hyodo ◽  
Makoto Kawasaki ◽  
Takashi Mera ◽  
Lei Chen ◽  
...  
Keyword(s):  
Elevated Plasma ◽  
Brain Areas ◽  
Conscious Rats ◽  
In Situ Hybridization Histochemistry ◽  
Calcitonin Gene ◽  
Cgrp Antagonist ◽  
Oxytocin Level ◽  
Supraoptic Nuclei ◽  
Time Point

We examined the effects of intracerebroventricular (ICV) administration of adrenomedullin 2 (AM2) on plasma oxytocin (OXT) and arginine vasopressin (AVP) levels in conscious rats. Plasma OXT levels were markedly increased 5 min after ICV administration of AM2 (1 nmol/rat) compared with vehicle and remained elevated in samples taken at 10, 15, 30, and 60 min. By contrast, plasma AVP levels were not significantly elevated in samples taken between 5 and 180 min after ICV administration of AM2 except at the 30-min time point. Fos-like immunoreactivity (Fos-LI) was observed in various brain areas, including the paraventricular (PVN) and the supraoptic nuclei (SON) after ICV administration of AM2 (2 nmol/rat) in conscious rats (measured at 90 min post-AM2 infusion). Dual immunostaining for OXT/Fos and AVP/Fos showed that OXT-LI neurons predominantly exhibited nuclear Fos-LI compared with AVP-LI neurons in the PVN and the SON. In situ hybridization histochemistry showed that ICV administration of AM2 (0.2, 1, and 2 nmol/rat) caused marked induction of the expression of the c- fos gene in the PVN and the SON. This induction was significantly reduced by pretreatment with both the calcitonin gene-related peptide (CGRP) antagonist CGRP-(8–37) (3 nmol/rat) and the AM receptor antagonist AM-(22–52) (27 nmol/rat). These results suggest that centrally administered AM2 mainly activates OXT-secreting neurons in the PVN and the SON, at least in part through the CGRP and/or AM receptors with marked elevation of plasma OXT levels in conscious rats.

Centrally administered adrenomedullin 5 activates oxytocin-secreting neurons in the hypothalamus and elevates plasma oxytocin level in rats

2009 ◽  
Vol 202 (2) ◽  
pp. 237-247 ◽  
Author(s):  
Hiroki Otsubo ◽  
Susumu Hyodo ◽  
Hirofumi Hashimoto ◽  
Makoto Kawasaki ◽  
Hitoshi Suzuki ◽  
...  
Keyword(s):  
Systemic Circulation ◽  
Neurosecretory Cells ◽  
Brain Areas ◽  
Conscious Rats ◽  
Paraventricular Nuclei ◽  
Calcitonin Gene ◽  
The Brain ◽  
Cgrp Antagonist ◽  
Oxytocin Level

We examined the effects of i.c.v. administration of adrenomedullin 5 (AM5) on the brain of conscious rats. We used porcine AM5 in the present study because rat AM5 has not been detected. We observed Fos-like immunoreactivity (LI) in the hypothalamus and brainstem of conscious rats after i.c.v. administration of AM5 (2 nmol/rat). Fos-LI, measured at 90 min post-AM5 injection, was observed in various brain areas, including the supraoptic (SON) and the paraventricular nuclei (PVN). Dual immunostaining for Fos/oxytocin (OXT) and Fos/arginine vasopressin (AVP) revealed that OXT-LI neurones predominantly colocalized Fos-LI compared with AVP-LI neurones in the SON and the PVN. Plasma OXT levels were significantly increased 5 min after i.c.v. administration of AM5 (1 nmol/rat) compared with vehicle and remained elevated in samples taken at 15 and 30 min without changes in plasma AVP levels at any time. In situ hybridization histochemistry showed that i.c.v. administration of AM5 (0.2, 1 and 2 nmol/rat) caused a marked induction of the expression of the c-fos gene in the SON and the PVN. This induction was significantly but not completely reduced by pretreatment with both the calcitonin gene-related peptide (CGRP) antagonist CGRP-(8–37; 3 nmol/rat) and the AM receptor antagonist AM-(22–52; 27 nmol/rat). Although porcine AM5 has not been detected yet in the brain, these results suggest that centrally administered porcine AM5 may activate OXT-secreting neurosecretory cells in the hypothalamus partly through AM/CGRP receptors and elicit secretion of OXT into the systemic circulation in conscious rats.

Role of peripheral capsaicin-sensitive neurons and CGRP in central vagally mediated gastroprotective effect of TRH

1994 ◽  
Vol 266 (5) ◽  
pp. R1610-R1614
Author(s):  
K. Kato ◽  
H. Yang ◽  
Y. Tache
Keyword(s):  
Monoclonal Antibody ◽  
Protective Effect ◽  
Sensory Neurons ◽  
Gastric Lesions ◽  
Conscious Rats ◽  
Calcitonin Gene ◽  
Efferent Pathways ◽  
Afferent Terminals ◽  
Cgrp Antagonist

We investigated in conscious rats the role of capsaicin-sensitive neurons and alpha-calcitonin gene-related peptide (CGRP), the form preferentially expressed in capsaicin sensory neurons, in mediating intracisternal thyrotropin-releasing hormone (TRH) analogue-induced vagal muscarinic gastroprotection against ethanol lesions. The TRH analogue RX-77368 (1.5 ng ic) reduced by 78 and 66% gastric hemorrhagic lesions induced by intragastric intubation of 60 and 80% ethanol, respectively. alpha-CGRP (1 nmol/kg iv) inhibited by 88% gastric lesions induced by 60% ethanol, and this peptide action was blocked by the CGRP antagonist, CGRP-(8-37) (128 nmol/kg iv). The protective effect of RX-77368 against 60% ethanol was completely abolished by the CGRP monoclonal antibody 4901 (4.8 mg/kg iv), CGRP-(8-37) (128 nmol/kg iv), and capsaicin pretreatment (125 mg/kg). Gastric lesions induced by 60% ethanol were not altered by the CGRP antagonist or antibody alone but were enhanced by capsaicin pretreatment. These results suggest that the gastroprotection induced by intracisternal TRH analogue involves an interaction between central vagal efferent pathways and splanchnic sensory afferent terminals containing CGRP.

scholarly journals Calcitonin Gene-Related Peptide Influences Bone-Tendon Interface Healing Through Osteogenesis: Investigation in a Rabbit Partial Patellectomy Model

2021 ◽  
Vol 9 (7) ◽  
pp. 232596712110039
Author(s):  
Huabin Chen ◽  
Hongbin Lu ◽  
Jianjun Huang ◽  
Zhanwen Wang ◽  
Yang Chen ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Bone Mineral ◽  
Calcitonin Gene Related Peptide ◽  
Control Group ◽  
Mineral Density ◽  
Related Peptide ◽  
Calcitonin Gene ◽  
Partial Patellectomy ◽  
Antagonist Group ◽  
Cgrp Antagonist

Background: Calcitonin gene-related peptide (CGRP), which has been shown to play an important role in osteogenesis during fracture repair, is also widely distributed throughout the tendon and ligament. Few studies have focused on the role of CGRP in repair of the bone-tendon interface (BTI). Purpose: To explore the effect of CGRP expression on BTI healing in a rabbit partial patellectomy model. Study Design: Controlled laboratory study. Methods: A total of 60 mature rabbits were subjected to a partial patellectomy and then randomly assigned to CGRP, CGRP-antagonist, and control groups. In the CGRP-antagonist group, the CGRP receptor antagonist BIBN4096BS was administered to block CGRP receptors. The patella–patellar tendon complex was harvested at 8 and 16 weeks postoperatively and subjected to radiographic, microlaser Raman spectroscopy, histologic, and biomechanical evaluation. Results: Radiographic data showed that local CGRP expression improved the growth parameters of newly formed bone, including area and volumetric bone mineral density ( P < .05 for both). Raman spectroscopy revealed that the relative bone mineral composition increased in the CGRP group compared with in the control group and the CGRP-antagonist group ( P < .05 for both). Histologic testing revealed that the CGRP group demonstrated better integration, characterized by well-developed trabecular bone expansion from the residual patella and marrow cavity formation, at the 8- and 16-week time points. Mechanical testing demonstrated that the failure load, ultimate strength, and stiffness in the CGRP group were significantly higher than those in the control group ( P < .05 for all), whereas these parameters in the CGRP-antagonist group were significantly lower compared with those in the control group at 16 weeks after surgery ( P < .05 for all). Conclusion: Increasing the local concentration of CGRP in the early stages of BTI healing enhanced osteogenesis in a rabbit partial patellectomy model and promoted healing of the BTI injury, whereas treatment using a CGRP antagonist had the opposite effect. However, exogenous CGRP expression did not induce novel bone remolding. Clinical Relevance: CGRP may have potential as a new therapy for BTI injuries or may be added to postoperative regimens to facilitate healing.

Expression of transforming growth factor alpha during development

1988 ◽  
Vol 66 (8) ◽  
pp. 1113-1121 ◽  
Author(s):  
V. K. M. Han ◽  
A. J. D'Ercole ◽  
D. C. Lee
Keyword(s):  
In Situ Hybridization ◽  
Growth Factor ◽  
Mrna Expression ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Alpha ◽  
Egf Receptors ◽  
Hybridization Histochemistry ◽  
In Situ Hybridization Histochemistry ◽  
Factor Alpha

Transforming growth factors (TGFs) are polypeptides that are produced by transformed and tumour cells, and that can confer phenotypic properties associated with transformation on normal cells in culture. One of these growth-regulating molecules, transforming growth factor alpha (TGF-α), is a 50 amino acid polypeptide that is related to epidermal growth factor (EGF) and binds to the EGF receptor. Previous studies have shown that TGF-α is expressed during rodent embryogenesis between 7 and 14 days gestation. To investigate the cellular sites of TGF-α mRNA expression during development, we have performed Northern analyses and in situ hybridization histochemistry on the conceptus and maternal tissues at various gestational ages. Contrary to previous reports, both Northern analyses and in situ hybridization histochemistry indicate that TGF-α mRNA is predominantly expressed in the maternal decidua and not in the embryo. Decidual expression is induced following implantation, peaks at day 8, and declines through day 15 when the decidua is being resorbed. In situ hybridization revealed that expression of TGF-α mRNA is highest in the region of decidua adjacent to the embryo and is low or nondetectable in the uterus, placenta, and embryo. In addition, we could not detect TGF-α mRNA expression in other maternal tissues, indicating that the induction of TGF-α transcripts in the decidua is tissue specific, and not a pleiotropic response to changes in hormonal milieu that occur during pregnancy. The developmentally regulated expression of TGF-α mRNA in the decidua, together with the presence of EGF receptors in this tissue, suggests that this peptide may stimulate mitosis and angiogenesis locally by an autocrine mechanism. Because EGF receptors are also present in the embryo and placenta, TGF-α may act on these tissues by a paracrine or endocrine mechanism.

scholarly journals Expression and localization of the mRNA for DNA (cytosine-5)- methyltransferase in mouse seminiferous tubules.

1994 ◽  
Vol 42 (9) ◽  
pp. 1271-1276 ◽  
Author(s):  
M Numata ◽  
T Ono ◽  
S Iseki
Keyword(s):  
In Situ Hybridization ◽  
Significant Role ◽  
Meiotic Prophase ◽  
Oligonucleotide Probe ◽  
Mouse Testis ◽  
Seminiferous Tubules ◽  
Hybridization Histochemistry ◽  
In Situ Hybridization Histochemistry

DNA (cytosine-5)-methyltransferase (DNA MTase) is the only enzyme known to be involved in the methylation of mammalian DNA. Although the expression of DNA MTase gene is abundant in the testis, little is known about the role of this enzyme during spermatogenesis. We examined the distribution of DNA MTase mRNA in mouse testis by in situ hybridization histochemistry with an oligonucleotide probe. The mRNA signal was observed in the seminiferous tubules and was localized predominantly in spermatogonia and spermatocytes, particularly during the earlier steps of meiotic prophase I, with maximal intensity in the early pachytene cells. These results suggest some significant role for DNA MTase in spermatogenesis.

scholarly journals Localization of CGRP and VEGF mRNAs in the mouse superior cervical ganglion during pre- and postnatal development

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Kazuyuki Mitsuoka ◽  
Yoko Miwa ◽  
Takeshi Kikutani ◽  
Iwao Sato
Keyword(s):  
In Situ Hybridization ◽  
Postnatal Development ◽  
Blood Supply ◽  
Superior Cervical Ganglion ◽  
Prenatal Development ◽  
Antisense Probe ◽  
Calcitonin Gene ◽  
Cervical Ganglion ◽  
Endothelial Growth Factor

The neuropeptide calcitonin gene-related peptide (CGRP) mediates inflammation and head pain by influencing the functional vascular blood supply. CGRP is a well-characterized mediator of receptor-regulated neurotransmitter release. However, knowledge regarding the role of CGRP during the development of the superior cervical ganglion (SCG) is limited. In the present study, we observed the localization of CGRP and vascular endothelial growth factor (VEGF-A) mRNAs during prenatal development at embryonic day 14.5 (E14.5), E17.5 and postnatal day 1 (P1) using in situ hybridization. The antisense probe for CGRP was detected by in situ hybridization at E14.5, E17.5, and P1, and the highest levels were detected at E17.5. In contrast, the antisense probe for VEGF-A was detected by in situ hybridization in gradually increasing intensity from E14.5 to P1. The differences in the expression of these two markers revealed specific characteristics related to CGRP concentration and release compared to those of VEGF-A during development. The correlation between CGRP and VEGF-A may influence functional stress and the vascular blood supply during prenatal and postnatal development.

Expression of the mRNAs for the Kv3.1 potassium channel gene in the adult and developing rat brain

1992 ◽  
Vol 68 (3) ◽  
pp. 756-766 ◽  
Author(s):  
T. M. Perney ◽  
J. Marshall ◽  
K. A. Martin ◽  
S. Hockfield ◽  
L. K. Kaczmarek
Keyword(s):  
In Situ Hybridization ◽  
Rat Brain ◽  
K Channel ◽  
Rnase Protection ◽  
Hybridization Histochemistry ◽  
Adult Rat ◽  
In Situ Hybridization Histochemistry ◽  
Adult Rat Brain ◽  
Developing Rat

1. The gene for a mammalian Shaw K+ channel has recently been cloned and has been shown, by alternative splicing, to give rise to two different transcripts, Kv3.1 alpha and Kv3.1 beta. To determine whether these channels are associated with specific types of neurons and to determine whether or not the alternately spliced K+ channel variants are differentially expressed, we used ribonuclease (RNase) protection assays and in situ hybridization histochemistry to localize the specific subsets of neurons containing Kv3.1 alpha and Kv3.1 beta mRNAs in the adult and developing rat brain. 2. In situ hybridization histochemistry revealed a heterogeneous expression pattern of Kv3.1 alpha mRNA in the adult rat brain. Highest Kv3.1 alpha mRNA levels were expressed in the cerebellum. High levels of hybridization were also detected in the globus pallidus, subthalamus, and substantia nigra reticulata. Many thalamic nuclei, but in particular the reticular thalamic nucleus, hybridized well to Kv3.1 alpha-specific probes. A subpopulation of cells in the cortex and hippocampus, which by their distribution and number may represent interneurons, were also found to contain high levels of Kv3.1 alpha mRNA. In the brain stem, many nuclei, including the inferior colliculus and the cochlear and vestibular nuclei, also express Kv3.1 alpha mRNA. Low or undetectable levels of Kv3.1 alpha mRNA were found in the caudate-putamen, olfactory tubercle, amygdala, and hypothalamus. 3. Kv3.1 beta mRNA was also detected in the adult rat brain by both RNase protection assays and by in situ hybridization experiments. Although the beta splice variant is expressed at lower levels than the alpha species, the overall expression pattern for both mRNAs is similar, indicating that both splice variants co-expressed in the same neurons. 4. The expression of Kv3.1 alpha and Kv3.1 beta transcripts was examined throughout development. Kv3.1 alpha mRNA is detected as early as embryonic day 17 and then increases gradually until approximately postnatal day 10, when there is a large increase in the amount of Kv3.1 alpha mRNA. Interestingly, the expression of Kv3.1 beta mRNA only increases gradually during the developmental time frame examined. Densitometric measurements indicated that Kv3.1 alpha is the predominant splice variant found in neurons of the adult brain, whereas Kv3.1 beta appears to be the predominant species in embryonic and perinatal neurons. 5. Most of the neurons that express the Kv3.1 transcripts have been characterized electrophysiologically to have narrow action potentials and display high-frequency firing rates with little or no spike adaptation.(ABSTRACT TRUNCATED AT 400 WORDS)

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