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Katsouni E, Sakkas P, Zarros A, Skandali N, Liapi C. The involvement of substance P in the induction of aggressive behavior. Peptides 2009; 30:1586-91. [PMID: 19442694 DOI: 10.1016/j.peptides.2009.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2009] [Revised: 05/03/2009] [Accepted: 05/04/2009] [Indexed: 10/20/2022]
Abstract
Aggression is a complex social behavior that involves a similarly complex neurochemical background. The involvement of substance P (SP) and its potent tachykinin receptor (NK1) in the induction of both defensive rage and predatory attack appears to be a consistent finding. However, an overall understanding of the nature of the SP involvement in the induction of aggressive behavior has not yet been fully achieved. The aim of this review is to summarize and present the current knowledge with regards to the role of SP in the induction of aggressive behavior and to synopsize: (a) its biochemical profile, and (b) the exact anatomical circuits through which it mediates all types of aggressive behavior. Future studies should seriously consider the potential use of this knowledge in their quest for the treatment of mood and anxiety disorders.
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Affiliation(s)
- Eleni Katsouni
- Department of Pharmacology, Medical School, National & Kapodistrian University of Athens, 75 Mikras Asias str, GR-11527, Athens, Greece
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Keire DA, Whitelegge JP, Bassilian S, Faull KF, Wiggins BW, Mehdizadeh OB, Reidelberger RD, Haver AC, Sayegh AI, Reeve JR. A new endogenous form of PYY isolated from canine ileum: Gly-extended PYY(1-36). ACTA ACUST UNITED AC 2008; 151:61-70. [PMID: 18501442 DOI: 10.1016/j.regpep.2008.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Revised: 03/21/2008] [Accepted: 04/01/2008] [Indexed: 11/30/2022]
Abstract
We purified and identified the peptide YY (PYY) forms present and determined their levels from a portion of the canine ileum directly adjacent to the cecum by a new extraction method designed to prevent and evaluate degradation of endogenous peptides. We used three reverse phase chromatography steps with radioimmunoassay of fractions for PYY-like-immunoreactivity (PYY-LI). The purified fractions underwent intact protein/peptide mass spectrometry identification and sequencing (i.e. "top-down" MS analysis). This analysis confirmed the identity of a new form of PYY, PYY(1-36)-Gly, which co-elutes with PYY(1-36)-NH(2) through all three of separation steps used. The PYY(1-36)-Gly form represents approximately 20% of the total PYY found in this region of the canine intestine. In addition, we also found that the PYY(3-36)-NH(2) form represents 6% of the total PYY in the canine ileo-cecal junction. The physiological implication of the Gly-extended form of PYY(1-36) warrants further investigation.
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Affiliation(s)
- David A Keire
- CURE: Digestive Diseases Research Center, VA GLAHS, Los Angeles, CA 90073 and Digestive Diseases Division, David Geffen School of Medicine at UCLA, Los Angeles, CA 90024, United States
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3
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Shigematsu N, Fukuda T, Yamamoto T, Nishioku T, Yamaguchi T, Himeno M, Nakayama KI, Tsukuba T, Kadowaki T, Okamoto K, Higuchi S, Yamamoto K. Association of cathepsin E deficiency with the increased territorial aggressive response of mice. J Neurochem 2008; 105:1394-404. [PMID: 18221376 DOI: 10.1111/j.1471-4159.2008.05242.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cathepsin E is an endolysosomal aspartic proteinase predominantly expressed in cells of the immune system, but physiological functions of this protein in the brain remains unclear. In this study, we investigate the behavioral effect of disrupting the gene encoding cathepsin E in mice. We found that the cathepsin E-deficient (CatE-/-) mice were behaviorally normal when housed communally, but they became more aggressive compared with the wild-type littermates when housed individually in a single cage. The increased aggressive response of CatE-/- mice was reduced to the level comparable to that seen for CatE+/+ mice by pretreatment with an NK-1-specific antagonist. Consistent with this, the neurotransmitter substance P (SP) level in affective brain areas including amygdala, hypothalamus, and periaqueductal gray was significantly increased in CatE-/- mice compared with CatE+/+ mice, indicating that the increased aggressive behavior of CatE-/- mice by isolation housing followed by territorial challenge is mainly because of the enhanced SP/NK-1 receptor signaling system. Double immunofluorescence microscopy also revealed the co-localization of SP with synaptophysin but not with microtubule-associated protein-2. Our data thus indicate that cathepsin E is associated with the SP/NK-1 receptor signaling system and thereby regulates the aggressive response of the animals to stressors such as territorial challenge.
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Affiliation(s)
- Naoki Shigematsu
- Department of Pharmacology, Graduate School of Dental Science, Kyushu University, Fukuoka, Japan
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Cape SS, Rehm KJ, Ma M, Marder E, Li L. Mass spectral comparison of the neuropeptide complement of the stomatogastric ganglion and brain in the adult and embryonic lobster, Homarus americanus. J Neurochem 2007; 105:690-702. [PMID: 18088365 DOI: 10.1111/j.1471-4159.2007.05154.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Neuropeptides in the stomatogastric ganglion (STG) and the brain of adult and late embryonic Homarus americanus were compared using a multi-faceted mass spectral strategy. Overall, 29 neuropeptides from 10 families were identified in the brain and/or the STG of the lobster. Many of these neuropeptides are reported for the first time in the embryonic lobster. Neuropeptide extraction followed by liquid chromatography coupled to quadrupole-time-of-flight mass spectrometry enabled confident identification of 24 previously characterized peptides in the adult brain and 13 peptides in the embryonic brain. Two novel peptides (QDLDHVFLRFa and GPPSLRLRFa) were de novo sequenced. In addition, a comparison of adult to embryonic brains revealed the presence of an incompletely processed form of Cancer borealis tachykinin-related peptide 1a (CabTRP 1a, APSGFLGMRG) only in the embryonic brain. A comparison of adult to embryonic STGs revealed that QDLDHVFLRFa was present in the embryonic STG but absent in the adult STG, and CabTRP 1a exhibited the opposite trend. Relative quantification of neuropeptides in the STG revealed that three orcokinin family peptides (NFDEIDRSGFGF, NFDEIDRSGFGFV, and NFDEIDRSGFGFN), a B-type allatostatin (STNWSSLRSAWa), and an orcomyotropin-related peptide (FDAFTTGFGHS) exhibited higher signal intensities in the adult relative to the embryonic STG. RFamide (Arg-Phe-amide) family peptide (DTSTPALRLRFa), [Val(1)]SIFamide (VYRKPPFNGSIFa), and orcokinin-related peptide (VYGPRDIANLY) were more intense in the embryonic STG spectra than in the adult STG spectra. Collectively, this study expands our current knowledge of the H. americanus neuropeptidome and highlights some intriguing expression differences that occur during development.
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Affiliation(s)
- Stephanie S Cape
- School of Pharmacy and Department of Chemistry, University of Wisconsin, Madison, WI 53705-2222, USA
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Nomura H, Furuta A, Suzuki SO, Iwaki T. Dorsal horn lesion resulting from spinal root avulsion leads to the accumulation of stress-responsive proteins. Brain Res 2001; 893:84-94. [PMID: 11222996 DOI: 10.1016/s0006-8993(00)03291-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The aim of this study was to demonstrate acute to subacute molecular episodes in the dorsal horn following root avulsion using immunohistochemical methods with the markers for synapses, astrocytes and such stress-responsive molecules as heat shock proteins (Hsps) and p38 MAP kinase (p38). Among them, Hsp27 was accumulated selectively in the injured substantia gelatinosa 24 h after avulsion injury. The localization of Hsp27 in astrocytes within the substantia gelatinosa was confirmed by the double immunofluorescence method using anti-Hsp27 antibody and either anti-synaptophysin antibody or anti-glutamine synthetase antibody and by immunoelectron microscopy for Hsp27. The pattern of Hsp27 expression subsequently changed from glial pattern to punctate pattern by 7 days. Immunoelectron microscopy revealed that the punctate pattern in the subacute stage corresponded to distal parts of the astrocytic processes. Hsp27 immunoreaction was decreased 21 days after root avulsion. In the distal axotomy model, Hsp27 was accumulated later in the ipsilateral dorsal horn in a punctate pattern from 7 days after the axotomy. Phosphorylation of p38 was detected in microglia in the dorsal horn following both avulsion and axotomy. Substance P was slightly decreased in the injured substantia gelatinosa in both the avulsion and axotomy models around 14-21 days. We conclude that Hsp27 is a useful marker for demonstrating dorsal horn lesions following avulsion injury and that avulsion injury may induce Hsp27 in the dorsal horn more rapidly than distal axotomy.
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Affiliation(s)
- H Nomura
- Department of Neuropathology, Neurological Institute, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
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Gregg TR, Siegel A. Brain structures and neurotransmitters regulating aggression in cats: implications for human aggression. Prog Neuropsychopharmacol Biol Psychiatry 2001; 25:91-140. [PMID: 11263761 DOI: 10.1016/s0278-5846(00)00150-0] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
1. Violence and aggression are major public health problems. 2. The authors have used techniques of electrical brain stimulation, anatomical-immunohistochemical techniques, and behavioral pharmacology to investigate the neural systems and circuits underlying aggressive behavior in the cat. 3. The medial hypothalamus and midbrain periaqueductal gray are the most important structures mediating defensive rage behavior, and the perifornical lateral hypothalamus clearly mediates predatory attack behavior. The hippocampus, amygdala, bed nucleus of the stria terminalis, septal area, cingulate gyrus, and prefrontal cortex project to these structures directly or indirectly and thus can modulate the intensity of attack and rage. 4. Evidence suggests that several neurotransmitters facilitate defensive rage within the PAG and medial hypothalamus, including glutamate, Substance P, and cholecystokinin, and that opioid peptides suppress it; these effects usually depend on the subtype of receptor that is activated. 5. A key recent discovery was a GABAergic projection that may underlie the often-observed reciprocally inhibitory relationship between these two forms of aggression. 6. Recently, Substance P has come under scrutiny as a possible key neurotransmitter involved in defensive rage, and the mechanism by which it plays a role in aggression and rage is under investigation. 7. It is hoped that this line of research will provide a better understanding of the neural mechanisms and substrates regulating aggression and rage and thus establish a rational basis for treatment of disorders associated with these forms of aggression.
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Affiliation(s)
- T R Gregg
- Department of Neurosciences, University of Medicine and Dentistry of New Jersey, Newark 07103, USA
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Abstract
This study examines the role of carboxypeptidase E (CPE) in processing pro tachykinin to form the final bioactive amidated undecapeptide, substance P (SP) in various rat brain regions. Cpe(fat)/Cpe(fat) mice brain tissue was analyzed for total SP forms (including intermediates), and final amidated SP was compared to Cpe+/Cpe+ and Cpe+/Cpe- controls. In all brain regions tested by radioimmunoassay, amidated fully processed SP was more than fivefold lower in Cpe(fat)/Cpe(fat) mice than in controls whereas total SP species levels were unchanged. This demonstrates that CPE is required for normal SP proteolytic processing. Substance P has numerous functions in the brain; therefore, SP deficiency due to the CPE mutation may contribute to the obese phenotype or even to other phenotypes not yet described in Cpe(fat)/Cpe(fat) mice.
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Affiliation(s)
- M D Perloff
- Department of Pharmacology and Experimental Therapeutics, Tufts University School of Medicine, Boston, MA 02111, USA
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Maggi CA. Tachykinins and calcitonin gene-related peptide (CGRP) as co-transmitters released from peripheral endings of sensory nerves. Prog Neurobiol 1995; 45:1-98. [PMID: 7716258 DOI: 10.1016/0301-0082(94)e0017-b] [Citation(s) in RCA: 345] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- C A Maggi
- Department of Pharmacology, A. Menarini Pharmaceuticals, Florence, Italy
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Marchand JE, Wurm HW, Kato T, Kream RM. Altered tachykinin expression by dorsal root ganglion neurons in a rat model of neuropathic pain. Pain 1994; 58:219-231. [PMID: 7816489 DOI: 10.1016/0304-3959(94)90202-x] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The experiments described in the present study approached nerve injury from both a biochemical and anatomical perspective by monitoring changes in expression of preprotachykinin (PPT) mRNA encoding the prototypic tachykinin substance P and related peptide species in neurons of the rat dorsal root ganglia (DRG) following unilateral chronic constriction injury of the sciatic nerve. In situ hybridization histochemistry (ISHH) analyses in conjunction with computer-assisted image processing were employed to quantify levels of PPT mRNA distributed in DRG neurons. Injury-induced changes in PPT mRNA expression by affected DRG neurons included: (1) at early postoperative times, generally increased levels of PPT mRNA associated with small and intermediate-size B cells exhibiting normal morphology, (2) at late postoperative times, markedly decreased levels of PPT mRNA associated with degenerating B cells, and (3) induction of PPT gene expression by large A cells which is highly correlated with degenerative morphological changes. The significant aspects of these changes are discussed with special emphasis on the contribution of altered transmitter expression by DRG neurons to the pathophysiology of causalgia. In particular, the induction of PPT gene expression by many of the large neurons undergoing degenerative changes may represent an important biochemical parameter which is associated with the development and persistence of experimental allodynia.
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Affiliation(s)
- James E Marchand
- Anesthesia Research, Department of Anesthesiology, Tufts University School of Medicine, New England Medical Center, Boston, MA 02111, USA
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Davis BJ, Kream RM. Distribution of tachykinin- and opioid-expressing neurons in the hamster solitary nucleus: an immuno- and in situ hybridization histochemical study. Brain Res 1993; 616:6-16. [PMID: 7689413 DOI: 10.1016/0006-8993(93)90185-p] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In several sensory systems, tachykinin- and opioid-expressing neurons functionally interact and influence the processing of afferent information. To determine whether a similar relationship exists for the processing of general and special (gustatory) visceral afferent information, the present study mapped the distributions of these two neuronal phenotypes within the nucleus of the solitary tract (NST) of the hamster by employing a combination of immuno- and in situ hybridization histochemistry (ISHH). The hamster was chosen because it is frequently used as a model in taste studies, yet there is a relative dearth of data about peptide expression or the classical neurotransmitters in the brainstem of this animal. The immunohistochemical analyses employed 2 highly selective antisera directed towards the prototypical tachykinin and opioid peptides, i.e. substance P (SP) and methionine enkephalin (ENK), respectively. Intense staining of fibers and preterminal/terminal puncta was concentrated in the rostral pole or gustatory zone of the NST. SP-, but not ENK-like immunoreactivity was also observed in long courses of axon bundles traversing the brainstem enroute to the NST. Local application of colchicine engendered the appearance of a moderate number of SP-positive somata that were mostly clustered in the medial, central and intermediate subnuclei, as well as being scattered throughout the remainder of the NST, including the gustatory zone. A low number of isolated ENK-positive somata were also observed throughout the NST. The somal areas of the SP- and ENK-positive somata averaged 86.3 and 81.8 microns 2, respectively. The ISHH studies were performed using 2 selective oligodeoxynucleotide probes with complementary sequences to mRNAs encoding gamma-preprotachykinin (PPT) and preproenkephalin (PPE) molecules. Overall, the cellular expression of PPT mRNA within the NST corresponded both in distribution and in number to those identified by immunohistochemical analyses using anti-SP serum. In contrast, ISHH analyses monitored a significantly greater number of PPE-expressing somata in the medial, central, intermediate and ventrolateral nuclei than were ENK immunoreactive. These findings indicate that tachykinin and opioid peptide phenotypes are represented in neurons throughout the hamster NST and suggest a functional role for PPT- and PPE-related peptide forms in the modulation of afferent general visceral and gustatory information.
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Affiliation(s)
- B J Davis
- Department of Cell Biology, University of Alabama, Birmingham 35294
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Abstract
The last decade has witnessed major breakthroughs in the study of tachykinin receptors. The currently described NK-1, NK-2, and NK-3 receptors have been sequenced and cloned from various mammalian sources. A far greater variety of tachykinin analogues are now available for use as selective agonists and antagonists. Importantly, potent nonpeptide antagonists highly selective for the NK-1 and NK-2 receptors have been developed recently. These improved tools for tachykinin receptor characterization have enabled us to describe at least three distinct receptor types. Furthermore, novel antagonists have yielded radioligand binding and functional data strongly favoring the existence of putative subtypes of NK-1 and especially NK-2 receptors. Whether these subtypes are species variants or true within-species subtypes awaits further evidence. As yet undiscovered mammalian tachykinins, or bioactive fragments, may have superior potency at a specific receptor class. The common C terminus of tachykinins permits varying degrees of interaction at essentially all tachykinin receptors. Although the exact physiological significance of this inherent capacity for receptor "cross talk" remains unknown, one implication is for multiple endogenous ligands at a single receptor. For example, NP gamma and NPK appear to be the preferred agonists and binding competitors at some NK-2 receptors, previously thought of as exclusively "NKA-preferring." Current evidence suggests that tachykinin coexistence and expression of multiple receptors may also occur with postulated NK-2 and NK-1 receptor subtypes. Other "tachykinin" receptors may recognize preprotachykinins and the N terminus of SP. In light of these recent developments, the convenient working hypothesis of three endogenous ligands (SP, NKA, and NKB) for three basic receptor types (NK-1, NK-2, and NK-3) may be too simplistic and in need of amendment as future developments occur (Burcher et al., 1991b). In retrospect, the 1980s contributed greatly to our understanding of the structure, function, and regulation of tachykinins and their various receptors. The development of improved, receptor subtype-selective antagonists and radioligands, in addition to recent advances in molecular biological techniques, may lead to a more conclusive pharmacological and biochemical characterization of tachykinin receptors. The 1990s may prove to be the decade of application, where a better understanding of the roles played by endogenous tachykinins (at various receptor subtypes) under pathophysiological conditions will no doubt hasten the realization of clinically useful therapeutic agents.
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Affiliation(s)
- C J Mussap
- School of Physiology and Pharmacology, University of New South Wales, Sydney, Australia
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Kream RM, Kato T, Shimonaka H, Marchand JE, Wurm WH. Substance P markedly potentiates the antinociceptive effects of morphine sulfate administered at the spinal level. Proc Natl Acad Sci U S A 1993; 90:3564-8. [PMID: 7682711 PMCID: PMC46341 DOI: 10.1073/pnas.90.8.3564] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The undecapeptide substance P and the alkaloid morphine sulfate are two agents previously thought to have opposite roles in the mediation of spinal nociceptive processes. The present report, however, demonstrates that low doses of substance P when coadministered with marginally effective doses of morphine sulfate into the rat subarachnoid space produce a markedly enhanced analgesic response, as monitored by the tail-flick test. This pharmacological effect is blocked by prior treatment with the opioid antagonist naloxone, indicating that the potentiated analgesic response is mediated by opioid-responsive neurons. In addition, the putative immediate precursor form of substance P (i.e., substance P-glycine) may substitute for the mature compound in the potentiated pharmacological effect. Moreover, the described synergism is unaffected by transection of the spinal cord, demonstrating the lack of supraspinal modulation of the observed phenomenon. Based on these observations, we are now able to dissociate opioid-potentiating and analgesic properties of substance P from traditional hyperalgesic effects realized at significantly higher concentrations. Consistent with previous biochemical data, a likely mechanism underlying the peptide-mediated enhancement of opioid analgesia may center on the ability of substance P to release endogenous opioid peptides within the local spinal cord environment. Finally, the pharmacological relationship of coadministered substance P and morphine sulfate established here supports the hypothesis that spinal tachykinin and opioid systems have a direct functional interaction in the modulation of local nociceptive responses.
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Affiliation(s)
- R M Kream
- Department of Anesthesiology, Tufts University School of Medicine, New England Medical Center, Boston, MA 02111
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Maggi CA, Patacchini R, Rovero P, Giachetti A. Tachykinin receptors and tachykinin receptor antagonists. JOURNAL OF AUTONOMIC PHARMACOLOGY 1993; 13:23-93. [PMID: 8382703 DOI: 10.1111/j.1474-8673.1993.tb00396.x] [Citation(s) in RCA: 516] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- C A Maggi
- Pharmacology and Chemistry Department, A. Menarini Pharmaceuticals, Florence, Italy
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14
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Marchand JE, Zaccheo TS, Connelly CS, Kream RM. Selective in situ hybridization histochemical analyses of alternatively spliced mRNAs encoding beta- and gamma-preprotachykinins in rat central nervous system. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1993; 17:83-94. [PMID: 8381913 DOI: 10.1016/0169-328x(93)90076-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The present study describes the development of an in situ hybridization histochemistry (ISHH) procedure which was employed to selectively monitor cellular distributions of the 2 major alternatively spliced beta- and gamma-species of mRNA encoding preprotachykinin (PPT) molecules found in rat CNS. For these purposes, 2 custom-designed oligodeoxynucleotide probes were synthesized corresponding to complementary sequences of beta- and gamma-PPT mRNAs. In particular, the gamma-selective probe was demonstrated to hybridize to the contiguous regions of RNA flanking the splice site formed by exclusion of exon 4. Initially, Northern blot analyses performed in conjunction with appropriate specificity controls demonstrated selective hybridization of the 32P-labeled beta- and gamma-selective probes to single bands of approximately 1.2-1.3 kilobases in size, consistent with previously established values for rat brain beta- and gamma-PPT mRNAs. In anatomical studies, results obtained from absorptions using competing nonradiolabeled oligonucleotides defined the specificity and selectivity of both probes for targeting their respective species of mRNA immobilized within sections of brain tissue. Extensive ISHH analyses using both beta- and gamma-selective probes demonstrated similar patterns of cellular labeling in all of the examined CNS areas. In addition, data obtained from analyses of adjacent thin sections of the dorsal root ganglia (DRG) indicated that beta- and gamma-PPT mRNAs were colocalized within individual DRG neurons, thereby suggesting generalized coexpression at the cellular level of both forms of mRNA. These data were complemented by semi-quantitative analyses which yielded cellular or intrinsic molar ratios of beta- to gamma-PPT mRNA of approximately 1:2-1:3, consistent with those values previously determined by nuclease protection analyses. In sum, a reasonable hypothesis evolving from the anatomical studies in combination with previous biochemical data supports the existence of a strong homeostatic mechanism involved in the maintenance of relatively constant intrinsic molar ratios of beta- to gamma-PPT mRNA by tachykinin-expressing neurons. The biological relevance of this putative fundamental relationship is discussed in the context of posttranslational processing of PPT molecules and of expression of mature tachykinins.
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Affiliation(s)
- J E Marchand
- Department of Anesthesiology, Tufts University School of Medicine, Boston, MA 02111
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15
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Shimonaka H, Marchand JE, Connelly CS, Kream RM. Development of an antiserum to the midportion of substance P: applications for biochemical and anatomical studies of substance P-related peptide species in CNS tissues. J Neurochem 1992; 59:81-92. [PMID: 1377229 DOI: 10.1111/j.1471-4159.1992.tb08878.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This report describes the generation and biochemical characterization of a high-affinity antiserum that recognizes an epitope contained in the midportion sequence of substance P, i.e., substance P4-10. Designated A47, this reagent bound a variety of related peptide species containing the substance P4-10 sequence with apparent equipotency. A double radioimmunoassay procedure was developed that utilized A47, in combination with a traditional high-affinity COOH-terminally directed anti-substance P serum, to provide quantification of mature and immature forms of substance P in CNS tissues. Across most rat CNS areas, levels of substance P-like immunoreactivity were consistently 15% higher when monitored by analyses using A47 versus anti-substance P serum. In the dorsal root ganglia, an apparent enhancement in levels of substance P-like immunoreactivity of approximately 40%, when quantified by analyses using A47 versus anti-substance P serum, was observed; this most likely reflected the presence of an active biosynthetic pool of intermediate processing forms of substance P in this tissue. Coordinated HPLC/radioimmunoassay analyses of extracted dorsal root ganglia tissues demonstrated multiple peaks of immunoreactivity corresponding to mature substance P and to several of its precursor forms found in the normal biosynthetic pathway. Of the total recovered HPLC-fractionated immunoreactivities, that corresponding to the putative immediate precursor to substance P, i.e., substance P-glycine, was the predominant peak. In an additional series of HPLC/radioimmunoassay analyses, selective decreases in immunoreactive peaks corresponding to precursor forms of substance P were observed in dorsal root ganglia tissues from rats treated with the neurotoxic agent capsaicin. These results indicated decreased turnover of substance P as a consequence of drug treatment. Finally, initial immunohistochemical analyses employing affinity-purified A47 produced an unusual pattern of labeling characterized by well defined punctate terminal elements within the superficial aspects of the dorsal horn of the spinal cord.
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Affiliation(s)
- H Shimonaka
- Anesthesia Research, Tufts University School of Medicine, Boston, Massachusetts 02111
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