Distributional pattern of oxytocin- and vasopressin-immunoreactivity in the neurohypophysis of the Djungarian hamster (Phodopus sungorus)

Summary The topography of oxytocin (OT)- and vasopressin (VP)-containing axons of the hypothalamo-neurohypophyseal system was studied in the neurohypophysis of the Djungarian hamster (Phodopus sungorus) by means of immunohistochemistry. Compared with other mammalian species, the neurohypophysis of Phodopus shows some peculiarities. Accumulations of OT-immunoreactivity around the distal vessels of the primary portal plexus can be observed in the distal median eminence and neural stem. This staining pattern indicates that OT is secreted into portal blood. In the neural lobe, OT- and VP-immunopositive fibers terminate in different areas. The vast majority of the OT-containing axons is distributed in the dorsal part of the neural lobe. In contrast, VP-containing axons are mainly found in the centre of the neural lobe up to the pars intermedia.     

Ultrastructural localization of neuropeptide FF, a new neuropeptide in the brain and pituitary of rats

The octapeptide FLFQPQRF-NH2 or neuropeptide FF ('F8Famide'; FMRFamide-like peptide'; 'morphine-modulating peptide') has been isolated from the bovine brain. In this study, the ultrastructural localization of neuropeptide FF-like immunoreactivity was examined with pre-embedding immuno-electron microscopy in the nucleus of the solitary tract and in the posterior lobe of the pituitary gland of an adult rat. Neuropeptide FF-like immunoreactivity was detected only in neuronal structures of the medial and commissural nuclei of the solitary tract and in the neurohypophysis. In the medulla, the peroxidase-antiperoxidase reaction product was localized in large (100 nm) dense-cored vesicles and in the cytoplasm of the neuronal perikarya, dendrites and axon terminals. In the labeled terminals, small (50 nm) clear vesicles rimmed with the peroxidase-antiperoxidase reaction product were seen. Synaptic contacts of labeled perikarya and dendrites with unlabeled axon terminals were observed. Labeled axon terminals formed contacts with unlabeled dendrites and perikarya. In the posterior lobe of the pituitary gland, neuropeptide FF-like immunoreactivity was localized in nerve terminals frequently associated with blood vessels. The results suggest that neuropeptide FF-like peptides are localized exclusively in neuronal structures and that they are synthesized in cell somata and released from axon terminals. In the brain, neuropeptide FF-like peptides may act as neuromodulators involved in the regulation of autonomic functions. The localization of neuropeptide FF-like immunoreactivity in the neurohypophysis suggests endocrine regulatory functions of these peptides.     

Glial cells positive for glial fibrillary acidic protein in the neurohypophysis of the Djungarian hamster (Phodopus sungorus)

Summary The presence and distribution of the glial fibrillary acidic protein (GFAP; an astrocytic marker protein associated with glial filaments) in the neurohypophysis of the Djungarian hamster (Phodopus sungorus) were investigated immunohistochemically. Our study revealed characteristic GFAP-staining patterns within the median eminence, infundibular stem and neural lobe. In the whole neurohypophysis, few glial cells showed immunoreactivity. In the neural lobe, immunopositive pituicytes appeared preferentially in the periphery. At the ultrastructural level, we found some pituicytes containing filaments, most notably in their processes. We thus demonstrated that, in contrast to the GFAP-immunoreactivity of cultured pituicytes, pituicytic GFAP-expression in vivo coincides with the presence of electron-microscopically detectable filaments.     

Distribution of subgroups of neuropeptide Y-immunoreactive and noradrenergic nerves in the female rat uterine cervix

Summary Nerves in the uterine cervix of the rat were examined with regard to co-existence of markers for noradrenaline and neuropeptide Y, and differential tissue innervation by nerves containing different combinations of these markers. Immunohistochemical labeling of single and adjacent serial cryostat sections, and double labeling was employed. Some animals were treated with the noradrenergic neurotoxin, 6-hydroxydopamine. In control animals neuropeptide Y-immunoreactive fibers were numerous in the myometrium and around arteries; noradrenergic fibers were few in the myometrium and moderate in number around arteries. Myometrial neuropeptide Y-immunoreactive fibers were not decreased, but apparently increased, in 6-hydroxydopamine-treated rats; in contrast, perivascular neuropeptide Y-immunoreactive fibers were markedly reduced, but not totally absent. Noradrenergic fibers were absent in the myometrium and around arteries following 6-hydroxydopamine treatment. Labeling of adjacent sections and double labeling revealed coincident labeling of markers for neuropeptide Y and noradrenaline in perivascular, but not myometrial, nerves. We concluded that most myometrial neuropeptide Y-immunoreactive nerves did not contain noradrenaline since they were not sensitive to 6-hydroxydopamine and did not stain doubly; however, perivascular neuropeptide Y-immunoreactive fibers which degenerated after 6-hydroxydopamine treatment and did label doubly must co-store noradrenaline. Some neuropeptide Y-immunoreactive perivascular fibers may contain neuropeptide Y but not noradrenaline. Thus, it appears there is a differential innervation of tissues in the cervix by neuropeptide Y/noradrenergic nerves; this could reflect a differential regulation of tissues innervated by these nerves.     

正常猕猴与人视网膜血管的比较

目的比较正常猕猴与人视网膜血管的异同,为进一步利用猕猴建立动物模型来研究视网膜血管打下基础。方法取健康成年猕猴眼球6只和人角膜移植供体剩余眼杯8只的视网膜,用ADP酶法进行血管染色,对两者视网膜血管的走行、血管分级、毛细血管分层以及黄斑区血管拱环等进行比较,测量结果进行统计学检验。结果猕猴与人的视网膜铺片经ADP酶法染色后见视网膜血管自穿出视盘后的一级血管逐渐分支变细,直至五级血管即毛细血管;在视盘旁、赤道部、周边部两者血管面积百分比没有差异;视盘旁血管分为多层,赤道部有两层,且深浅层间相互交通,周边部仅见一层毛细血管且较稀疏;两者黄斑区毛细血管均较密集,有形态完整呈不规则状的血管拱环,血管面积百分比以及血管拱环的面积、周长和直径没有差异。结论猕猴与人在视网膜血管走行、分级、毛细血管分层以及黄斑区血管拱环等多方面有良好的相似性,可用作人类视网膜血管、尤其是黄斑区视网膜血管研究的良好动物模型。     

Localization and characterization of neuropeptide Y-like peptides in the brain and islet organ of the anglerfish (Lophius americanus)

Summary Results from a previous report demonstrate that more than one molecular form of neuropeptide Y-like peptide may be present in the islet organ of the anglerfish (Lophius americanus). Most of the neuropeptide Y-like immunoreactive material was anglerfish peptide YG, which is expressed in a subset of islet cells, whereas an additional neuropeptide Y-like peptide(s) was localized in islet nerves. To learn more about the neuropeptide Y-like peptides in islet nerves, we have employed immunohistochemical and biochemical methods to compare peptides found in anglerfish islets and brain. Using antisera that selectively react with either mammalian forms of neuropeptide Y or with anglerfish peptide YG, subsets of neurons were found in the brain that labelled with only one or the other of the antisera. In separate sections, other neurons that were labelled with either antiserum exhibited similar morphologies. Peptides from brains and islets were subjected to gel filtration and reverse-phase high performance liquid chromatography. Radioimmunoassays employing either the neuropeptide Y or peptide YG antisera were used to examine chromatographic eluates. Immunoreactive peptides having retention times of human neuropeptide Y and porcine neuropeptide Y were identified in extracts of both brain and islets. This indicates that peptides structurally similar to both of these peptides from the neuropeptide Y-pancreatic polypeptide family are expressed in neurons of anglerfish brain and nerve fibers of anglerfish islets. The predominant form of neuropeptide Y-like peptide in islets was anglerfish peptide YG. Neuropeptide Y-immunoreactive peptides from islet extracts that had chromatographic retention times identical to human neuropeptide Y and porcine neuropeptide Y were present in much smaller quantities. These results are consistent with the hypothesis that peptides having significant sequence homology with human neuropeptide Y and porcine neuropeptide Y are present in the nerve fibers that permeate the islet.     

Distribution of immunoreactive somatostatin in the primate hypothalamus

Immunocytochemical methods were used to compare the localization of somatostatin (SRIF) in the human and rhesus monkey hypothalamus. The distribution of SRIF-containing cell bodies and fibers is similar in the two species. Perikarya are located predominantly in the periventricular region and to a lesser extent in the ventromedial nucleus. Fibers occur in dense clusters within the periventricular region, ventromedial nucleus, arcuate nucleus, median eminence, and pericommissural area of both species. Analysis of serial sections suggests that fibers originate from cells in the periventricular region, extend ventrally through the ventromedial and arcuate nuclei to terminate around the portal vessels of the infundibular stalk, and thereby participate in the regulation of anterior pituitary function. Somatostatinergic fibers are also found surrounding non-immunoreactive perikarya in the ventromedial nucleus and periventricular region of both primates. This arrangement may support somatostatin's postulated role as a neurotransmitter or neuromodulator. The strong similarity between the localization of hypothalamic SRIF in the human and rhesus monkey supports the use of the rhesus monkey as a model for the study of somatostatin as a neuroendocrine regulatory in the human.     

Immunocytochemical localization of LHRH in the median eminence,infundibular stalk,and neurohypophysis

Summary The distribution of luteinizing hormone-releasing hormone (LHRH) was studied by light-microscopic immunocytochemistry in the hypothalamo-pituitary complex of humans, monkeys, ferrets, bats, and rats. LHRH-immunoreactive fibers were identified in the median eminence of all these species, but the precise location of these fibers varied. In rats, the vast majority of LHRH fibers in the median eminence was confined to the external zone. In contrast, in bats, most of the LHRH fibers were located in the internal zone. While these two species represent opposite extremes in distribution of LHRH fibers within the median eminence, intermediate conditions were found in humans, monkeys, and ferrets, as considerable numbers of fibers occurred in both internal and external zones. In addition to fibers in the median eminence, large numbers of LHRH-immunoreactive fibers were identified traversing the infundibular stalk and entering the neural lobe of the pituitary in all species examined except the rat. In rats, only occasional fibers were observed in the infundibular stalk, and they did not project into the neural lobe. However, in humans, monkeys, ferrets, and bats, groups of LHRH-immunoreactive fibers extended well into the substance of the posterior pituitary. Most of these fibers appeared to terminate near the adenohypophysis, but others coursed away from the anterior lobe and penetrated deeper portions of the neural lobe. These observations, made in several mammalian species, indicate that multiple routes may exist in the median eminence/stalk/pituitary complex for the delivery of LHRH to the anterior pituitary.     

Occurrence of bombesin-like immunoreactivity in the brain of the cartilaginous fish,Scyliorhinus canicula

Summary The presence and distribution of bombesin-like material were investigated in the brain of the cartilaginous fishScyliorhinus canicula using conventional immunocytochemical techniques. Perikarya containing bombesin-like immunoreactivity were identified in the hypothalamus, within the magnocellular component of the preoptic nucleus. Some immunopositive elements appeared to be of cerebrospinal fluid-contacting type. Beaded immunoreactive fibers were seen crossing the ventral telencephalon and the whole hypothalamus. An important tract of fibers was found in the infundibular floor and in the median eminence, in close contact with the vascular system of the pituitary portal plexus. A moderate number of positive fibers innervated the habenular complex and the dorsal wall of the posterior tuberculum. These findings indicate that a neuropeptide strictly related to amphibian bombesin is located in specific hypothalamic neurons ofS. canicula. The distribution of the immunoreactive fibers and terminals suggests that, in fish, this peptide, may be involved in neuroendocrine and neuromodulator functions.     

Distribution of peptidyl-glycine alpha-amidating monooxygenase immunoreactivity in the brain,pituitary and islet organ of the anglerfish (Lophius americanus)

Peptidyl-glycine alpha-amidating monooxygenase (PAM; EC 1.14.17.3) is an enzyme that catalyzes conversion of glycine-extended peptides to alpha-amidated bioactive peptides. Two peptides that are processed at their carboxyl-termini by this enzyme are neuropeptide Y and anglerfish peptide Y, both of which possess a C-terminal glycine that is used as a substrate for amidation. Results from previous reports have demonstrated that neuropeptide Y-like and anglerfish peptide Y-like immunoreactivities are present in the brain of anglerfish (Lophius americanus). Furthermore, neuropeptide Y-like peptides, namely anglerfish peptide Y and anglerfish peptide YG (the homologues of pancreatic polypeptide) are present in the islet organ of this species. Neuropeptide Y has also been localized in the anterior, intermediated and posterior lobes of the pituitary gland in a variety of species. In order to learn more about the distribution of the enzyme responsible for alpha amidation of these peptides in the brain and pituitary and to specifically investigate the relationship of this enzyme to peptide synthesizing endocrine cells of the anglerfish islet, we performed an immunohistochemical study using several antisera generated against different peptide sequences of the enzyme. PAM antisera labeled cells in the islet organ, pituitary and brain, and fibers in the brain and pituitary gland. The PAM staining pattern in the brain was remarkably similar to the distribution of neuropeptide Y immunoreactivity reported previously. Clusters of cells adjacent to vessels in the anterior pituitary displayed punctate PAM immunoreactivity while varicose fibers were observed in the pituitary stalk and neurohypophysis. Endocrine cells of the islet organ were differentially labeled with different PAM antisera. Comparison of the staining patterns of insulin, glucagon, and anglerfish peptide Y in the islet organ to PAM immunoreactivity suggests a distribution of forms of PAM enzyme in insulin and anglerfish peptide Y-containing cells, but no overlap with glucagon-producing cells. The results also indicate that PAM immunoreactivity is widely distributed in the brain, pituitary and islet organ of anglerfish in cells that contain peptides that require presence of a C-terminal glycine for amidation.     

Neuropeptide Y immunoreactivity in the mammalian liver: pattern of innervation and coexistence with tyrosine hydroxylase immunoreactivity

Summary The distribution of nerve fibers displaying neuropeptide Y immunoreactivity in relationship to the catecholaminergic innervation of rat, guinea pig, and rabbit liver was investigated by single- and double-label immunofluorescence methods. In all three species, neuropeptide Y-immunoreactive fibers are prominent in association with the vasculature, biliary pathway, and stromal compartment. The neuropeptide Y innervation of the parenchyma, on the other hand, differs among the three species in term of density. It is quite sparse in the rat and rabbit, particularly in the former species. In the guinea pig liver, numerous single, varicose neuropeptide Y-containing nerve fibers innervate the hepatic parenchyma; often, thin processes surround single hepatocytes and lie close to sinusoids. The immunoreactive pattern of tyrosine hydroxylase, a marker for catecholaminergic neurons and fibers, is comparable to that of neuropeptide Y. Most neuropeptide Y-containing nerve fibers also contain tyrosine hydroxylase immunoreactivity, in all three species, with the exception of the rabbit parenchyma, where a substantial proportion of catecholaminergic fibers lack immunoreactivity for neuropeptide Y. Finally, systemic administration of the sympathetic neurotoxin, 6-hydroxydopamine, in rats and guinea pigs resulted in virtually complete elimination of both neuropeptide Y- and tyrosine hydroxylase-immunoreactive fibers. These findings are consistent with the hypothesis that neuropeptide Y-containing nerve fibers form a subpopulation of the sympathetic innervation of the mammalian liver, which is likely to originate from prevertebral sympathetic ganglia.     

The appearance of monoamines in the adult and developing neurohypophysis of Gallus gallus

Summary Most of the specific monoamine fluorescence of the fowl neurohypophysis is found in the eminentia mediana and the infundibular stem. The densest accumulation of fluorescent structures is located to the zona externa and the subependymal layer, whereas generally only scattered fluorescence is demonstrable in the fiber layer. The neural lobe tissue is provided with very fine smooth fibers often difficult to distinguish. Spectrofluorimetric determinations have shown that noradrenaline is the major catecholamine in the chick neurohypophysis. From the embryological studies it is evident that the monoamine fluorescence first appears in the subependymal layer, the fiber layer and the neural lobe (after about 15 days of incubation). The zona externa fluorescence is not visible until just before hatching. 10 days after hatching the fluorescence intensity of the chick neurohypophysis is similar to that of the adult. Some comparisons are also made with the appearance of monoamines in the mouse.The authors take great pleasure in expressing their warmest thanks for laboratory facilities and good advice provided by Dr. Bengt Falck at the Institute of Histology, Lund, Sweden.This work was supported by grants from the Swedish Natural Science Research Council (project no. 99-35 and 2180-16), from the United States Public Health Service (NB-06701-02) and from the Swedish Medical Research Council (B-69-14 x -56-05 C).     

Postnatal development of sympathetic and sensory innervation of the rhesus monkey ovary.

We have used immunofluorescence to study the postnatal development of the sympathetic and sensory innervation to the rhesus monkey (Macaca mulatta) ovary. Sympathetic nerves were identified as adrenergic by their content of tyrosine hydroxylase (TH)-like immunoreactivity and as peptidergic by the presence of neuropeptide Y (NPY). Fibers containing substance P (SP) or calcitonin gene-related peptide (CGRP)-like immunoreactivity were considered as sensory, whereas vasoactive intestinal peptide (VIP)-positive fibers were only defined as peptidergic because VIP may be present in both sympathetic and sensory nerves. Ovaries from neonatal (2-mo-old), juvenile (9-18-mo-old), peripubertal (3-3.5-yr-old), adult (9-14-yr-old), and senescent (20-27-yr-old) monkeys were studied. At all ages, with the exception of senescence, TH-, NPY-, and VIP-containing fibers were associated with follicles in different developmental stages. In peripubertal and adult animals, some primordial follicles were found to be selectively innervated by VIPergic fibers that almost completely encircled each follicle. Both sympathetic and VIP fibers were also detected in the interstitial tissue and associated with the ovarian vasculature at all ages. The number of sympathetic and VIP fibers increased significantly (p < 0.01) between 2 mo and 9-18 mo of age, and again increased (p < 0.01) around the age of puberty (approximately 3 yr of age). After this time, the number of NPY and TH fibers remained constant. Conversely, the number of VIP fibers decreased (p < 0.05) by 9-14 yr of age, but remained constant thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparative study of the ultrastructure of the median eminence,infundibular stem and neural lobe of the hypophysis of the rat

Summary The ultrastructure of the infundibulum has been studied and compared with that of neural lobe in normal rats. The neurohemal areas of the median eminence are similar to those of the stem but differ from those of neural lobe. The infundibular axons which end around the primary capillaries of the portal system are of a significantly finer caliber. Secondly they contain a different vesicle population. They lack the large (1500 Å–2100 Å) neurosecretory vesicles so abundant in neural lobe axon terminals but contain a smaller (less than 1000 Å) type of vesicle with an osmiophilic center. These dense-core vesicles are consistently present in the many infundibular levels examined, although they are not as numerous as the neurosecretory ones of neural lobe. They are outnumbered by vesicles of the synaptic type, whereas in neural lobe the neurosecretory ones predominate. Another difference involves the electron lucent, neurosecretory vesicle. These are abundant in neural lobe axons, but comparable aggregations of them have not been seen in infundibular axon endings of the neurohemal areas. In contrast, the internal zone of median eminence and the interior of the stem display, in addition to the fine axons, many large fibers which by size and content match the ones of neural lobe. However, careful study indicates that these are axis cylinders and not axon endings.These observations lead to the conclusion that the small calibered axons which terminate around the infundibular capillaries of the portal system constitute a separate group, and are clearly distinguishable at the ultrastructural level from the large supraoptico-neurohypophyseal axons. The latter normally traverse the infundibulum but terminate in neural lobe.This investigation was supported by U.S.P.H.S. Research Grant 5 RO 1 NB 02321-05, National Institute of Neurological Diseases and Blindness. — The author is particularly indebted to Mrs. Nora Tong for her excellent technical assistance throughout the course of this study.     

The development of the hypophysial portal system in the White-crowned Sparrow,Zonotrichia leucophrys gambelii

Summary The development of the hypophysial portal system has been studied in 35 embryos and 45 nestlings of the White-crowned Sparrow. The primordium of the hypophysis is vascularized by the infundibular (primary) capillary plexus, supplied by the right and left infundibular arteries, which, in the embryo, are constant branches of the right and left internal carotid arteries.The cellular proliferation and differentiation of the pars distalis into rostral and caudal lobes is accompanied by a penetration of portal vessels from the infundibular (primary) capillary plexus into these lobes beginning on the fifth day of incubation. The cellular proliferation of the rostral lobe of the pars distalis and development of the rostral group of the portal vessels precedes that of the caudal lobe of the pars distalis and the development of the caudal group of the portal vessels.The periglandular vessels, which originate in younger embryos from the infundibular (primary) capillary plexus, apparently become a part of the portal vessels.The portal vessels are the sole blood supply to the developing pars distalis of the White-crowned Sparrow; there is no evidence of a direct arterial supply at anytime during embryonic development. The neural-lobe artery appears at the end of incubation as a secondary branch of the right and left infundibular arteries. The rostral and caudal groups of the portal vessels are well-developed at the end of incubation (17–29 mm CRL) when aldehyde-fuchsin positive neurosecretory material first appears in the supraoptic and paraventricular nuclei, in the median eminence and in the neural lobe.The differentiation of the median eminence into rostral and caudal divisions begins at the end of the nestling period although its adult form is not achieved until later. The formation of the portal zone begins at the end of incubation (17–29 mm CRL) and is completed by the time of fledging.Dedicated to Professor Dr. W. Bargmann in honor of his 60th birthday.The investigations reported herein were supported by a research grant (HE 07240 NEUA) from the National Institutes of Health to Professor Vitums, by funds for biological and medical research made available by State of Washington Initiative Measure No 171 to Professor Vitums, by a research grant from the Deutsche Forschungsgemeinschaft to Professor Oksche, by aresearch grant (NB 01353) from the National Institutes of Health to Professor Farner, and by a Research Career Development Award from the National Institute of Arthritis and Metabolic Diseases (5 K 3 AM-18,370) to Professor King. We are grateful to Professor Bargmann for his generosity in making available the facilities of the Anatomisches Institut Kiel for this investigation. We wish to thank Frau Karin Graap and Mrs. Dianne Reno for technical assistance and Miss Janice Austin for the preparation of the drawings.     

实验猕猴肺部CT影像断层初步观察

目的应用CT技术对成年实验猕猴胸部肺窗进行断层扫描观察,探讨CT技术对猕猴肺部疾病的临床诊断意义,建立正常猴肺部CT断层扫描图谱,为CT技术在猕猴解剖学的研究、疾病的临床诊断及科学实验方面的应用,提供影像学的基础资料。方法经过触诊、叩诊、听诊、体温、呼吸率、心率、呼吸运动、血液常规等检查,选择健康猴10只,雌雄各半,年龄分别为5～10岁,进行肺部CT断层扫描检测。试验猴全身麻醉后,置于CT诊断床上,取头前尾后仰卧位进行肺部扫描,获取肺窗扫描图像。对具有解剖意义的扫描图像的每个层面的主要结构（肺叶、气管、动脉血管、静脉血管等）进行标注。结果 （1）获得具有解剖意义的肺窗扫描图像13张。（2）在断层扫描的图像中,肺、气管、较大血管等组织器官界面清晰。肺为左右两侧,左肺分为上叶、中叶、下叶,右肺分为上叶、中叶、下叶、奇叶四部分。不同的断层面分别可见肺部左主支气管、右主支气管、支气管、血管等组织。（3）肺部较小或细小的血管、神经组织界面不清晰。结论 （1）应用CT获得的正常猕猴胸部肺窗断层扫描图像表明,正常健康猴双肺纹理清晰,走行自然,肺野透光度良好,双肺无异常实质病变影像。（2）获得了健康猕猴肺部的CT影像学资料,为猕猴肺部疾病的诊断,提供了一种安全、方便又准确的新依据,建立了成年健康猕猴肺部CT断层解剖研究的背景资料。     

Serum dehydroepiandrosterone sulfate concentrations across the life span of laboratory-housed rhesus monkeys

Cross-sectional studies of humans have shown that dehydroepiandrosterone sulfate (DHEAS) peaks shortly after sexual maturation and declines thereafter, suggesting that the progressive reduction in DHEAS may play a role in the aging process and in the development of age-related morbidity. The present study examines changes in DHEAS concentrations across the life span of rhesus monkeys as part of the development of this primate model for studies of aging. Serum concentrations of DHEAS were measured in 792 laboratory-housed rhesus monkeys (Macaca mulatta) aged 0.5-36 years (527 females, 265 males). DHEAS concentrations in all monkeys were used to formulate an equation that describes two levels of decline of DHEAS with age. The most rapid decline occurs from infancy until approximately 5 years of age. The decline then occurs gradually with increasing age. There were no signs of an andrenarche just prior to sexual maturation, as is seen in humans or the great apes. This equation can be used to predict the expected mean serum DHEAS concentration and normal ranges of male or female rhesus monkeys at any age greater than 5 months.     

Polypeptide YY- and neuropeptide Y-immunoreactive cells and nerves in the endocrine and exocrine pancreas of some vertebrates: An onto- and phylogenetic study

Summary The occurrence of polypeptide YY- and neuropeptide Y-immunoreactive cells and nerves in the pancreas of some species from all the eight main vertebrate groups (cyclostomes, cartilaginous fish, bony fish, amphibia, reptiles, birds, and mammals) was investigated. In addition, an ontogenetic study of these neurohormonal peptides was performed, using the rat pancreas. The distribution of these two peptides was compared with that of the structurally closely related pancreatic polypeptide.Polypeptide YY-immunoreactive cells were found to occur in the endocrine pancreas and neuropeptide Y-immunoreactivity was observed both in neurons and nerve fibres. The polypeptide YY-immunoreactive cells were limited to mammals and reptiles only. Neuropeptide Y-immunoreactive neurons and nerves were observed in reptiles, birds, and mammals only. One reptilian species (out of three) and one mammalian (out of six) failed to show any kind of immunoreactivity for the polypeptide or neuropeptide. Pancreatic polypeptide-immunoreactive cells were found in all the species examined except in the hagfish islet.In rat foetuses, polypeptide YY-immunoreactive cells and neuropeptide Y-immunoreactive nerve elements were first demonstrated at the seventeenth day of gestation, whereas pancreactic peptide-immunoreactive cells did not appear until postnatally, namely in two day-old rats. The polypeptide-containing cells, a new cell type in the endocrine pancreas, are rare. In contrast to the pancreatic peptide cells, they do not seem to have any kind of regional distribution.     

GnRH-prohormone-containing neurons in the primate brain: immunostaining for the GnRH-associated peptide

The structure of the prohormone for mammalian gonadotropin releasing hormone (proGnRH) includes the GnRH decapeptide followed by a 56 amino acid GnRH-associated peptide (GAP). In this study, we compared immunostaining of brain neurons and fibers for GAP and GnRH in fetal rhesus monkeys and juvenile baboons. We used antisera against different portions of human and rat GAP (proGnRH 14-24, proGnRH 40-53, and proGnRH 52-66) or against GnRH and the PAP technique. Liquid phase absorption with GAP or GnRH confirmed the specificity of these antisera. Major accumulations of GAP immunoreactive (GAP+) perikarya occurred in the medial septal and preoptic areas and the nucleus of the diagonal band of Broca (44.6% in rhesus, 49.6% in baboon), supraoptic region including the area dorsal to the optic tract (21.9% in rhesus, 23.0% in baboon), and the medial basal hypothalamus (15.7% in rhesus, 16.4% in baboon), especially at the infundibular lip. Occasional cell bodies were scattered throughout the hypothalamic and forebrain regions studied. GAP+ fibers were widely distributed, but formed well-defined pathways such as the periventricular and ventral hypothalamic tract. In addition, GAP+ nerve terminals with various densities occurred in the lamina terminalis, the zona externa of the infundibulum, and behind the infundibular stalk. Fetal rhesus macaques had more GAP+ cell bodies, denser fiber networks, and more distinct pathways than juvenile baboons. However, fiber and terminal immunostaining was somewhat less intense for GAP than GnRH in comparable regions. These results indicate that proGnRH (GAP) is present in the same population of neurons as GnRH in the primate brain. They also suggest that post-translational products of proGnRH are present in perikarya, axons and terminals, and that GnRH and GAP and/or further cleavage products are consecreted into hypophysial portal blood in the primate.     

Corticotrophic cells in the rostral zone of the pars intermedia and in the adjacent neurohypophysis of the rat and mouse

Summary In the mouse, the rostral zone of the pars intermedia is almost exclusively composed of typical corticotrophic cells. They are located around and even within the neural stalk, at the level of transition between stalk and neural lobe. In the rat, the corticotrophic cells of the rostral zone are found in scattered islets among the MSH producing cells, and also in the neural lobe. In both the rat and mouse, these cells are in direct contact with various types of nerve terminals. Synaptoid contacts with aminergic and neurosecretory nerve fibers are observed. Furthermore they are also closely related to the hypophysial portal vessels. Following adrenalectomy, the cells located in the neurohypophysis always react more intensely than tose in the rostral zone. The functional significance of these corticotrophic cells which are subject to both humoral and neural regulation remains as yet hypothetical. Their participation in neurogenic stress response seems probable.