Estrogen modulation of neuropeptides: somatostatin, neurotensin and substance P, in the ventrolateral and arcuate nuclei of the female guinea pig

In the guinea pig, steroid target cells reside in the ventrolateral hypothalamic nucleus (VLH), an important site in the mediation of female receptive behavior, and in the arcuate nucleus (AR), a structure essential for stimulation effects of ovarian hormones on gonadotropin secretion. However, the mechanisms by which these steroid-dependent reproductive neuroendocrine processes occur are only partially understood. Estrogen is known to affect the hypothalamus content of certain neuropeptides. In the present study, we investigated the effects of estradiol benzoate (EB) on immunoreactivity of neurons containing one of three following neuropeptides: somatostatin (SOM), neurotensin (NT) and substance P (SP) in VLH and AR. The number of immunoreactive (IR)-neurons was quantified in anatomically matched sections through VLH and AR of ovariectomized (OVX), OVX + EB and OVX + oil-treated guinea pigs. Analysis of variance revealed that the number of SOM-IR and SP-IR neurons significantly increased in all regions of VLH of OVX + EB-treated guinea pigs as compared to OVX or OVX + oil-treated animals (P < 0.01) but showed no EB effect on the number of NT-IR neurons. Although the number of SOM-IR and NT-IR neurons slightly increased following treatment with EB in AR, analysis of variance revealed no significant change. The present results provide additional information relevant to possible involvement of these neuropeptides in facilitation of female typical sexual behavior.     

Effect of the neuropeptides beta-MSH, neurotensin, NPY, PHI, somatostatin and substance P on proliferation of lymphocytes in vitro

Various neuropeptides were tested in a wide dose range for an effect on lymphocyte-proliferation. The response of spleen cells to the mitogen phytohaemagglutinin (PHA) was stimulated by somatostatin in doses ranging from 10(-6) to 10(-18) M. The effect of somatostatin was only seen when the peptide was added at the start of incubation, indicating an effect on the inductive phase of mitogen stimulation. Weak stimulative effects were also seen of somatostatin (10(-6) M) on spontaneous proliferation of thymocytes and of beta-MSH on PHA-treated thymocytes and PHA-treated spleen cells when the peptide was added after 24 h of culture.     

颅脑外伤后局部脑组织中P物质和生长抑素的表达及意义

本文旨在分子水平探讨人脑外伤后神经肽的变化,为脑外伤后病理生理变化机制提供理论依据。采用免疫组织化学技术和多功能真彩色病理图像分析系统(CMIAS)对31例脑外伤患者局部脑损伤区和12例无脑损伤猝死患者相同脑区神经细胞中P物质(SP),生长抑素(SS)的表达进行了检测。结果得出脑伤患者局部伤区及周围神经细胞中SP、SS表达较尸检对照组明显减少并具时程特点。但与伤情及预后无显著关系。本实验表明SP、SS在颅脑损伤的病理生理过程中起了重要作用。     

Intestinal peristalsis associated with release of immunoreactive substance P

The release of immunoreactive substance P into the vascular bed of the isolated small intestine of the guinea-pig was investigated. Raising the intraluminal pressure to 5 mbar for 5 min initiated peristalsis and stimulated the release of substance P. The substance P releasing effect of pressure stimulation was reduced by 46% when hexamethonium (240 microM) was added to the perfusion solution. The ganglion stimulant drug dimethylphenylpiperazinium (32 microM) also stimulated the release of substance P; its effect was completely prevented by hexamethonium (240 microM). Intraarterial infusion of capsaicin (22 microM), a neurotoxin known to act on sensory substance P-containing neurones, stimulated the release of substance P and caused intestinal contractions. The motor effect of capsaicin in the gut can thus be explained by release of substance P from sensory nerve endings in the gut. Systemic pretreatment of the guinea-pigs with capsaicin abolished the release of substance P due to capsaicin, whereas that evoked by elevated intraluminal pressure or dimethylphenylpiperazinium was not reduced. This means that substance P released in the course of peristalsis or by dimethylphenylpiperazinium originates from neurones intrinsic to the intestine. These findings indicate that intestinal peristalsis is associated with the release of substance P from enteric neurones. Substance P is likely to be a neurotransmitter involved in the coordination of the peristaltic reflex.     

Kainic acid induced seizures: changes in somatostatin, substance P and neurotensin

The neuropeptides somatostatin, neurotensin and substance P were investigated in rats during and after limbic seizures induced by systemic injection of kainic acid (10 mg/kg, i.p.). Three hours after injection of the toxin, pronounced decreases (40-50%) in somatostatin-like immunoreactivity in frontal cortex, striatum, dorsal hippocampus and amygdala/pyriform cortex were observed. Concomitantly, neurotensin-like and substance P-like immunoreactivities were also reduced in the frontal cortex and the hippocampus. These early decreases in peptide levels may result from increased release and subsequent inactivation of the peptides during acute seizures. At later time intervals, 3, 10 and 30 days after injection of kainic acid, the initially decreased peptide levels were partially normalized. However, the reduction in somatostatin-like immunoreactivity in amygdala/pyriform cortex and striatum persisted up to 30 days. Neurotensin-like immunoreactivity remained decreased in the frontal cortex. On the other hand, neurotensin- and substance P-like immunoreactivities were increased in the striatum and substantia nigra 10-30 days after injection of kainic acid. These late changes in peptide levels may suggest destruction of peptidergic neurons or adaptive changes induced by the convulsions. Pretreatment of rats with cysteamine (100 mg/kg, i.p.), an agent which decreases brain somatostatin levels, had no effect on the intensity of kainic acid induced convulsions, although a slightly earlier onset of seizures was observed. The changes in peptide levels, especially the marked decreases in somatostatin content after systemic injection of kainic acid, suggest considerable acute and chronic alterations in peptidergic systems caused by limbic convulsions.     

Intrathecal somatostatin, somatostatin analogs, substance P analog and dynorphin A cause comparable neurotoxicity in rats.

Rats chronically implanted with intrathecal catheters received intrathecal injections (10 microliters followed by 10 microliters saline flush) of either saline (n = 5), somatostatin (100 micrograms, n = 10), the somatostatin analog BIM 23003 (100 micrograms, n = 5), the somatostatin analog SMS 201-995 (100 micrograms, n = 5), the substance P analog [D-Pro2, D-Trp7,9] SP (10 micrograms, n = 10), or dynorphin A (1-17) (20 nmol, n = 8). These doses (somatostatin, substance P and dynorphin A) were selected based on previous studies in which they caused significant motor deficits. Effects on thermal cutaneous nociception, behavior, motor function and spinal cord histopathology were evaluated. All peptides caused severe neurotoxicity, evidenced by flaccid hind leg paralysis and lumbar spinal neuronal degeneration, which was accompanied by an inflammatory reaction in meninges and spinal gray matter. Histopathological changes had developed within 24 h after injection of somatostatin, substance P analog and dynorphin A, showing mild to severe neuronal degeneration and mild inflammatory responses in spinal cord and meninges. Significant antinociceptive effects, due to severe neurotoxic effects, were only observed following intrathecal injection of SMS 201-995 and the substance P analog. Potential neurotoxic mechanisms of the different peptides are discussed.     

Immunohistochemical studies of substance P, cholecystokinin-octapeptide and somatostatin in dorsal root ganglia of the rat

Immunofluorescence histochemistry was used to determine the distribution of substance P, somatostatin and cholecystokinin-octapeptide-immunoreactive perikarya in C6, T6, T10, L2 and S1 dorsal root ganglia of rat. Five different categories of immunoreactive primary afferent neurons were distinguished on the basis of cell size, cytology and peptide immunoreactivities. The population of small cells (diameter less than 20 microns) included three groups which were identified as containing somatostatin, substance P, or substance P + cholecystokinin-octapeptide. Two groups of cells were identified in an intermediate size range (diameter 21-43 microns) as containing cholecystokinin-octapeptide or cholecystokinin-octapeptide + substance P. These categories may reflect four distinct populations of primary afferent neurons. The relative abundance of dorsal root ganglion cells containing substance P, cholecystokinin-octapeptide or somatostatin immunoreactivities was significantly different within segmental levels. More neurons were immunoreactive for cholecystokinin-octapeptide than substance P in ganglia C6, T6 and T10. Somatostatin-containing cells were fewest in number regardless of level. The number of immunoreactive cells also varied among spinal ganglia. L2 contained the greatest number of immunoreactive cells; S1 contained the fewest. These studies are relevant to our understanding of dorsal root ganglia in two ways. Firstly, the data document significant variation in the distribution of peptide-containing neurons among spinal ganglia associated with various cord levels. The variation in peptide-containing cell populations among spinal ganglia may reflect differences in populations of modality-specific primary afferent fibers as well as in populations of somatic and visceral primary afferent fibers at each level. Furthermore, the data indicate that the relative abundance of a population of peptide-containing primary afferent neurons cannot be extrapolated from the examination of spinal ganglia from a single level. Secondly, substance P and cholecystokinin-octapeptide did not co-exist in all spinal ganglion cells as previously reported. In conjunction with immunostaining characteristics and cell size, the differential distribution of the two peptides defined four cell types, raising the possibility that each cell type may mediate a different modality.     

实验性大鼠肝脏癌变过程中生长抑素受体2表达的意义

目的：研究生长抑素受体2（SSTR2）在肝癌癌变过程中的表达和分布，探讨SSTR2在肝癌发生过程的作用。方法：二乙基亚硝胺溶液(DENA)诱发SD大鼠发生肝癌，RT-PCR和免疫组化检测肝硬化肝组织、肝癌中SSTR2的mRNA和蛋白表达，比较不同时期肝组织中SSTR2-mRNA和蛋白的表达。结果：DENA诱癌8周后，可见肝癌形成。诱癌8周时，癌旁肝组织SSTR2-mRNA明显高于正常肝脏（1.794±0.212 vs 0.950±0.138,P<0.05），随着诱癌时间的延长，SSTR2-mRNA的表达逐渐增强，到16周时到最高（2.053±0.169），随后逐步下降（22周时低至1.468±0.107），而肝癌组织SSTR2-mRNA表达只为1.219±0.249。免疫组化检测SSTR2蛋白表达发现，SSTR2主要位于胞浆和细胞膜，SSTR2蛋白表达的变化与SSTR2-mRNA的变化一致。结论：SSTR2在实验性肝硬化早期表达逐步升高，随着肝硬化的加重和肝细胞癌变的发生，SSTR2表达逐渐下降。SSTR2表达下降可能与肝细胞癌发生、发展密切相关。     

Developmental changes in bombesin,substance P,somatostatin and vasoactive intestinal polypeptide in the rat brain

The regional distribution of the 4 neuropeptides, bombesin, substance P, somatostatin and vasoactive intestinal polypeptide (VIP) were investigated in the developing rat brain. Specific radioimmunoassay and immunocytochemistry were employed. VIP and bombesin were undetectable in the foetal brain whereas substance P and somatostatin were shown to be present in all regions as early as 14 days postcoitus. There was a dramatic postnatal increase in all 4 peptides in most regions. These results are discussed and compared with results of previous investigations of the ontogeny of the classic neurotransmitters.     

Effect of substance P and somatostatin on migration of polymorphonuclear (PMN) cells in vitro

The effects of the two neuropeptides, substance P (SP) and somatostatin (SOM), on the migration of polymorphonuclear cells derived from 13 volunteers were investigated. The neuropeptides were applied in concentrations between 10^–12 and 10^–6 M. Only at a concentration of 10^–6 M SP did the chemotaxis of PMN cells increase slightly but slatistically significantly. In contrast to SP, SOM showed a significant dose-dependent stimulation of chemotaxis, which was first traceable at 10^–10 M and increased up to 10^–6 M. Although it is uncertain whether in vivo SP and SOM contribute directly to the invasion of PMN cells into the joint cavity, the influence of these neuropeptides on PMN migration in vitro is a further indication of the neuropeptide involvement in the genesis of inflammation.     

Co-expression of neuropeptides in the cat's striatum: an immunohistochemical study of substance P, dynorphin B and enkephalin.

The expression of tachykinin-like and opioid-like peptides was studied in medium-sized neurons of the caudate nucleus in tissue from adult cats pretreated with colchicine. Two methods, a serial thin-section peroxidase-antiperoxidase technique and a two-fluorochrome single-section technique, were applied. Quantitative estimates were made mainly with the peroxidase-antiperoxidase method. The numbers of neurons expressing substance P-like, dynorphin B-like, and enkephalin-like immunoreactivity were recorded in regions identified, respectively, as striosomes and extrastriosomal matrix. Striosomes were defined by the presence of clustered substance P-positive and dynorphin B-positive neurons and neuropil. Tests for the co-existence of enkephalin-like peptide and glutamate decarboxylase-like immunoreactivity were also made with the peroxidase-antiperoxidase method. Co-expression of substance P-like and dynorphin B-like immunoreactivities was the rule both in striosomes and in the matrix. In striosomes, substance P-like immunoreactivity was found in 96% of dynorphin B-immunoreactive neurons, and in the matrix 89% of dynorphin B-positive cells contained substance P-like immunoreactivity. Substance P/dynorphin B-positive neurons corresponded to over half (57%) of the neurons in striosomes but only 39% of the neurons in the matrix. Both in the matrix and in striosomes, about two-thirds of all neurons (63% and 65%, respectively) were identified as enkephalin-positive. Among all substance P/dynorphin B-positive medium-sized neurons, 76% also contained enkephalin-like antigen. The enkephalin-positive neurons characterized by triple peptide co-existence (enkephalin/substance P/dynorphin B) represented a mean of 63% of striosomal enkephalin-positive neurons (41% of all striosomal neurons) and 35% of matrical enkephalin-positive neurons (26% of all matrical neurons). Finally, nearly all enkephalin-positive neurons were immunoreactive for glutamate decarboxylase, and therefore probably GABAergic, but only about half the glutamate decarboxylase-positive population was enkephalin-immunoreactive. These findings suggest that neuropeptides from three distinct precursors may be co-localized in single medium-sized neurons in the striatum, and that the differential patterns of co-expression of substance P-like, dynorphin B-like, and enkephalin-like peptides may confer functional specializations upon subpopulations of GABAergic neurons giving rise to the efferent projections of the striatum. The linked expression of substance P-like and dynorphin B-like peptides in single neurons both in striosomes and matrix suggests that some regulatory mechanisms controlling peptide expression apply regardless of compartment.(ABSTRACT TRUNCATED AT 400 WORDS)     

5-HT、生长抑素及 P物质在海洛因依赖大鼠直肠的定位和表达

目的 探讨海洛因依赖期间大鼠直肠内5-HT、生长抑素(SS)和P物质(SP)免疫反应(IR)细胞的形态学改变.方法 选取成年SD大鼠,分为海洛因依赖组(30只)、盐水对照组(30只)和正常对照组(6只),皮下注射海洛因建立大鼠海洛因依赖模型.取直肠组织用免疫组织化学SABC法及图像分析法进行研究.结果 与正常组及盐水对照组比较,海洛因依赖组大鼠直肠5-HT、SS及SP免疫反应细胞的细胞数均增多(P<0.05). 5-HT、SS、 SP-IR细胞免疫染色增强,图像分析显示,海洛因依赖期间大鼠直肠内5-HT、SS及SP 免疫反应细胞的平均灰度值均低于正常组及盐水对照组(P<0.05);其中5-HT、SS-IR细胞以31d时间组最低(P<0.05),SP-IR细胞以38d时间组最低(P<0.01).结论 海洛因依赖期间直肠5-HT、SS和SP-IR细胞的细胞数及平均灰度值均发生变化,提示5-HT、SS和SP合成和分泌增多.     

Effect of heroin dependence on 5-hydroxytryptamine, somatostatin and substance P immunoreactive cells in the rat ileum

目的:探讨海洛因依赖对大鼠回肠5-羟色胺(5-HT)、生长抑素(SS)和P物质(SP)免疫反应(IR)细胞的影响.方法:选取成年SD大鼠,分为正常对照组、盐水对照组和海洛因依赖组,建立大鼠海洛因依赖模型,取回肠组织用免疫组织化学SABC法及图像分析法进行研究.结果:与正常及盐水对照组比较,海洛因依赖组大鼠回肠5-HT免疫反应细胞增多,SS及SP免疫反应细胞数无明显变化.5-HT、SS-、SP-IR细胞免疫显色增强,图像分析显示海洛因依赖期间大鼠回肠内5-HT、SS及SP-IR细胞的平均灰度值均低于正常及盐水对照组.结论:海洛因依赖期间,回肠5-HT、SS和SP-IR细胞的5-HT、SS和SP表达增加.     

I-J expression is not associated with murine chromosome 4

I-J originally mapped within the murine major histocompatibility complex (H-2) between the EB and Ea loci using intra-H-2 recombinants. Cloning of this segment of H-2 shows no DNA that can be ascribed to I-J. Various hypotheses have attempted to explain this dilemma. One hypothesis attributes a chromosome 4 locus with I-Jk expression. This hypothesis requires the AKR/J and A/WySn mouse strains to be I-Jk negative. In the present report we show that AKR/J spleen cells express I-Jk surface molecules and that both the AKR/J and A/WySn mouse strains produce functional I-Jk-bearing suppressor factors to poly(Glu50Tyr50). Our data imply that mapping of I-J-determining genes to chromosome 4 may be premature.     

Sensory neuropeptides (substance P) and 4-11 SP enhance human neutrophils chemiluminescence; the role of L-arginine

Investigations on the effect of a naturally occurring neuropeptide, substance P (SP) and one of its synthetic analogues, 4-11 SP, on luminol-enhanced chemiluminescence (CL) of human polymorphonuclear leukocytes (PMN) are presented. Both peptides elicited a strong burst of CL with different time course and dose-response curves. SP- and tuftsin-induced CL were similar, both peptides sharing a Lys-Pro-Arg terminal; 4-11 SP, which lacks the terminal arginine, peaked earlier than the natural peptide. Surprisingly when PMN were pre-incubated with L-arginine (L-Arg) this enhancing effect was abolished or diminished. L-Arg and an L-Arg synthetic derivative (PCF-39) were also evaluated; PCF-39 strongly increased the PMN CL, while L-arginine showed a significant CL enhancement only in 43% of the donors tested. Peptide- and arginine-induced CL were Ca++/MG++ dependent.     

A survey of substance P, somatostatin, and neurotensin levels in aging in the rat and human central nervous system

Levels of the neuropeptides substance P, somatostatin, and neurotensin were measured by radioimmunoassay in regions of the rat and human central nervous system (CNS) in aging. Somatostatin levels were significantly lower only in the corpus striatum of older rats. Substance P levels and neurotensin levels were generally stable with aging as were levels of somatostatin in regions other than the corpus striatum. In post-mortem human CNS tissues, no significant negative correlations of levels of the three peptides were observed with time to refrigeration or time to freezer for the samples. In the human CNS, there were no significant age-related alterations in substance P levels in frontal cortex, thalamus, hypothalamus, caudate nucleus, globus pallidus, or substantia nigra. There was a significant age-related decrease in substance P levels in the human putamen. This age-related decrease was not present in tissues from victims of Huntington's disease nor was there any striking difference in substance P levels as a function of duration of the disease. There were no significant age-related changes in somatostatin levels in human frontal cortex, caudate nucleus, putamen, medial globus pallidus, or substantia nigra. Among these same regions, there was a significant age-related decrease in neurotensin levels only in the pars compacta and pars reticulata of the human nigra. These results implicate neuropeptides in aging processes in certain regions of the CNS. There are differences between rats and humans with respect to neuropeptides in the aging process in the CNS. Deterioration of some neuropeptide pathways in and to human basal ganglia may be involved in the suspected functional deterioration of parts of the extrapyramidal system in aging.     

A survey of substance P, somatostatin, and neurotensin levels in aging in the rat and human central nervous system

Levels of the neuropeptides substance P, somatostatin, and neurotensin were measured by radioimmunoassay in regions of the rat and human central nervous system (CNS) in aging. Somatostatin levels were significantly lower only in the corpus striatum of older rats. Substance P levels and neurotensin levels were generally stable with aging as were levels of somatostatin in regions other than the corpus striatum. In post-mortem human CNS tissues, no significant negative correlations of levels of the three peptides were observed with time to refrigeration or time to freezer for the samples. In the human CNS, there were no significant age-related alterations in substance P levels in frontal cortex, thalamus, hypothalamus, caudate nucleus, globus pallidus, or substantia nigra. There was a significant age-related decrease in substance P levels in the human putamen. This age-related decrease was not present in tissues from victims of Huntington's disease nor was there any striking difference in substance P levels as a function of duration of the disease. There were no significant age-related changes in somatostatin levels in human frontal cortex, caudate nucleus, putamen, medial globus pallidus, or substantia nigra. Among these same regions, there was a significant age-related decrease in neurotensin levels only in the pars compacta and pars reticulata of the human nigra. These results implicate neuropeptides in aging processes in certain regions of the CNS. There are differences between rats and humans with respect to neuropeptides in the aging process in the CNS. Deterioration of some neuropeptide pathways in and to human basal ganglia may be involved in the suspected functional deterioration of parts of the extrapyramidal system in aging.     

Sequential expression of functions during macrophage differentiation in murine bone marrow liquid cultures

In the presence of a colony-stimulating factor, murine bone marrow cells proliferate and differentiate into macrophages. This culture system was taken as a model to study the expression of various functions by macrophages in the course of maturation. Several tests were performed daily and in parallel from the same batch of cells. It was found that certain functions were expressed early and were also characteristic for mature macrophages such as Fc receptors, phagocytosis of latex beads and unspecific esterase activity. Other functions appeared and disappeared in an ordered sequence, such as the response to macrophage migration inhibitory factor and chemotactic factor as well as the production of interferon and of plasminogen activator. The time course of functional expression was strongly dependent on proliferation of precursor cells as well as proliferation of differentiated macrophages. It is suggested that the phenotypic expression of functions during differentiation is the basis for the functional heterogeneity of macrophages.