Satiety, hunger and regional brain content of cholecystokinin/gastrin and met-enkephalin immunoreactivity in sheep

Cholecystokinin (CCK) and met-enkephalin (MEK) related peptides have been shown to alter feeding behavior subsequent to their injection into the peripheral circulation or directly into the brains of several species. To evaluate the potential role of endogenous brain pools of these peptides in feeding, groups of sheep were sacrificed either immediately following a meal (satiated) or after various intervals of food deprivation (hungry). Content of CCK-gastrin immunoreactivity in the anterior hypothalami of satiated sheep was elevated compared to 2, 4, or 24 hours of food deprivation. Content of MEK increased progressively with longer intervals of fasting (4 and 24 hours) in the amygdala and basomedial hypothalamus, whereas olfactory bulb content decreased with a similar time course. The results support a potential role for anterior hypothalamic CCK/gastrin in behaviors of satiety, whereas MEK neurons of limbic/rhinencephalic regions appear to form part of a separate circuit gradually activated by increasing hunger. Results are discussed in terms of potential target regions of the peptides, as well as the regional levels and feeding response of sheep as compared to available data from other species.     

Leishmania tropica and Leishmania donovani: solid phase radioimmunoassay using leishmanial excreted factor

A radioimmunoassay for the quantitative determination of anti-leishmanial excreted factor (EF) antibody in rabbit sera was developed. The assay, using Leishmania tropica and Leishmania donovani promastigotes EF, purified by either extraction with phenol followed by fractionation on a Sephadex G-100 column or by the dissociation of EF antibody complexes, was shown to be sensitive and reproducible. Using monospecific anti-EF antibodies, levels of as low as 0.06-0.12 micrograms/ml of anti-EF IgG could be detected. The specificity of the assay was assessed by inhibition with homologous and heterologous EF. Only minor cross-reactivity with heterologous EF was observed, and as little as 2.5 micrograms/ml of EF could be detected. Sera from kala-azar patients showed only 1.8-3.1 times more anti-EF activity, as compared with uninfected controls. No specificity was observed with sera from kala-azar patients with regard to the type of EF used. Almost the same activity was obtained with both EF from L. tropica and L. donovani. No anti-EF antibodies were detected in sera from patients with cutaneous leishmaniasis.     

Chicken egg yolk antibodies for cytokinin analysis

The production, isolation, and purification of specific chicken immunoglobulins (Igs) against three main groups of naturally occurring cytokinins are reported. The specific Igs directed against, respectively, zeatin riboside, dihydrozeatin riboside, and isopentenyladenosine are extracted from the egg yolk and used in radioimmunoassays that allow the quantification in parallel of pmol of the cytokinins in plant extracts. As little as 50 fmol of zeatin riboside, 20 fmol of isopentenyladenosine, and 40 fmol of dihydrozeatin riboside can be detected. The levels of cytokinins measured in the radio-immunoassay correlate well with physicochemical analysis methods such as high performance liquid chromatography (HPLC) with UV spectrum detection and HPLC-coupled mass spectrometric detection. Cross-reactivity studies indicate that the assay is not affected by most of the structurally related compounds. The respective antibody preparations recognized zeatin riboside, dihydrozeatin riboside, and isopentenyladenosine and the corresponding free bases. The results obtained when analyzing crude plant extracts are expressed as zeatin riboside equivalents, dihydrozeatin riboside equivalents, and isopentenyladenosine equivalents.Abbreviations B binding activity - B ₀ maximal binding - B ₁ unspecific binding - GC gas chromatography - HPLC high performance liquid chromatography - LC-MS HPLC-coupled mass spectrometry - MOPS 4-morpholinepropanesulfonic acid - RIA radioimmunoassay - TBS Tris-buffered saline - (diH)Z dihydrozeatin - (diH) [9R]Z dihydrozeatin riboside - iP isopentenyladenine - [9R]iP isopentenyladenosine - Z zeatin - [9R]Z zeatin riboside - [9G]iP isopentenyladenine-9-glucoside - [9R-5P]iP isopentenyladenosine-5-monophosphate     

The Regional Distribution of N-Acetylaspartylglutamate (NAAG) and Peptidase Activity Against NAAG in the Rat Nervous System

Abstract: N -Acetylaspartylglutamate (NAAG), a prevalent peptide in the vertebrate nervous system, may be hydrolyzed by extracellular peptidase activity to produce glutamate and N -acetylaspartate. Hydrolysis can be viewed as both inactivating the peptide after synaptic release and increasing synaptic levels of ambient glutamate. To test the hypothesis that NAAG and the peptidase activity that hydrolyzes it coexist as a unique, two-stage system of chemical neurotransmission, 50 discrete regions of the rat CNS were microdissected for assay. In each microregion, the concentration of NAAG was determined by radioimmunoassay and the peptidase activity was assayed using tritiated peptide as substrate. The NAAG concentration ranged from 2.4 nmol/mg of soluble protein in median eminence to 64 in thoracic spinal cord. Peptidase activity against NAAG ranged from 54 pmol of glutamate produced per milligram of membrane protein per minute in median eminence to 148 in superior colliculus. A linear relationship was observed between NAAG peptidase and NAAG concentration in 46 of the 50 areas, with a slope of 2.26 and a correlation coefficient of 0.45. These data support the hypothesis that hydrolysis of NAAG to glutamate and N -acetylaspartate is a consistent aspect of the physiology and metabolism of this peptide after synaptic release. The ratio of peptide concentration to peptidase activity was >0.3 in the following four areas: ventrolateral medulla and reticular formation where the peptide is concentrated in axons of passage, thoracic spinal cord, where NAAG is concentrated in ascending sensory tracts as well as motoneuron cell bodies, and ventroposterior thalamic nucleus.     

Existence and Functions of Neurotens in Human Early Placental Villi

ＥｘｉｓｔｅｎｃｅａｎｄＦｕｎｃｔｉｏｎｓｏｆＮｅｕｒｏｔｅｎｓｉｎＨｕｍａｎＥａｒｌｙＰｌａｃｅｎｔａｌＶｉｌｌｉＺＨＡＮＧＣｈｏｎｇ－ｌｉ（张崇理）;ＣＨＥＮＧＬｉ－ｒｅｎ（程丽仁）,ＳＨＥＮＷｅｉ－ｂｉｎ（沈卫斌）;ＹＩＮＨｏｎｇ（殷红）;ＨＵ...     

苦瓜和瓜蒌体内皮质醇含量的测定

利用灵敏度高,专一性强的放射免疫法（ＲＩＡ）测定了苦瓜和瓜萎不同器官中皮质醇的含量。结果表明：苦瓜和瓜萎各器官均含有皮质醇,且含量在５０～４５０ｎｇ／ｇ．ＦＷ;顶芽中含量最高,其次是花器官;苦瓜和瓜篓雌花皮质醇含量明显高于雄花,且雌花在授粉后当天含量最高,说明皮质醇可能在植物的生长发育过程中起某种作用。     

Pro-enkephalin gene derived peptides in the porcine stomach: cellular distribution and molecular forms

Antisera to the enkephalin variants Met-enk Arg6Phe7 and Met-enk Arg6Gly7Leu8 have been used in immunohistochemistry and radioimmunoassay studies of hog stomach. In the mucosa of the antrum, but not fundus, there was identified a population of immunoreactive endocrine-like cells. When extracts of antral mucosa were fractionated by gel filtration on Sephadex G50 the predominant immunoreactive forms of Met-enk Arg6Phe7 and Met-enk Arg6Gly7Leu8 were found to elute before the standards, and were compatible with N-terminally extended variants. In the muscle layers of both antrum and fundus, immunoreactive nerve fibers were found, these were especially numerous in the myenteric plexus. In extracts of the antral muscle, 50-60% of both Met-enk Arg6Phe7 and Met-enk Arg6Gly7Leu8 immunoreactivity eluted in the position of the standards and the remainder had the properties of N-terminally extended variants. In the fundus muscle the variants accounted for 70-80% of total activity. The results indicate that the proenkephalin gene is expressed in neurones and endocrine cells of the hog stomach. The different patterns of molecular forms found in different regions of the stomach suggest that the precursor is processed by different pathways in different populations of endocrine cells and neurones.     

Isolation and characterization of rat vasoactive intestinal peptide

We have used gel filtration, ion exchange chromatography, affinity chromatography and reversed-phase HPLC to isolate vasoactive intestinal peptide from rat intestine. Microsequence analysis of 1 nmole peptide indicated that the sequence was identical to the porcine octacosapeptide VIP. In radioimmunoassay with four antisera and in the turkey pancreas bioassay, rat VIP was equipotent with highly purified preparations of porcine, human and canine VIP. A less basic rat VIP-variant was also isolated and the N-terminal decapeptide region that was sequenced was identical with that of porcine VIP.     

Immunochemical study on PHI/PHM with use of synthetic peptides

We have synthesized PHI and PHM (human PHI) as well as their fragments, PHI (1-6), PHI (1-15), PHI (14-19), PHI (14-27), PHI (20-27), PHM (1-15) and PHM (13-27), by the solution or solid-phase method for peptide synthesis. Using the highly purified synthetic peptides as immunogens or haptenic immunogens, five kinds of PHI/PHM specific antisera were produced. The major antibody-recognition sites of the five antisera were located respectively in the PHI C-terminal (R8201), in the PHI N-terminal (R8403), in the PHM C-terminal (R8502), and in the PHM whole molecule (R8702 and R8703). Radioimmunoassays (RIAs) with antisera R8201, R8403 and R8502, respectively, showed a wide distribution of immunoreactive (IR) PHI/PHM in porcine and human gastrointestinal and brain tissues. The concentrations of IR-PHI in the porcine gastrointestinal tissues, however, differed between the R8201 and R8403 RIAs employed for measurement. By using these two different PHI RIAs, the IR-PHI in the porcine brain tissue extract was shown to be almost a single component coeluting with synthetic PHI in gel filtration. The IR-PHI in the extract of porcine lower intestine on the other hand, contained, besides a PHI-like component, unidentified component(s) eluting immediately after synthetic PHI in gel filtration; this crossreacted with the PHI C-terminal specific R8201 antiserum but not with the N-terminal specific R8403 antiserum, suggesting the presence of the C-terminal-related fragment(s) of PHI in the tissues.     

Localisation and measurement of VIP in the genitourinary system of man and animals

VIP is present in the genitourinary system of man and animals. In man the highest concentrations are found in the penis, the uterus and vagina and in the urinary bladder. VIP nerves heavily innervate the erectile tissue of the male external genitalia, the uterine smooth muscle and blood vessels, the seromucous glands of the cervix, and the lamina propria and vaginal epithelium. In the urinary bladder, VIP nerves are located beneath the transitional epithelium, in the lamina propria and in the smooth muscle. Other areas well innervated by VIP nerves include the prostate, seminal vesicles and vasa deferentia. Chemical (phenol- and 6-OHDA) or surgical (hypogastric or pelvic nerve section) extrinsic denervation fail to deplete the genitourinary system of its VIP content, supporting the view that VIP-containing nerves originate from local ganglion cells. Indeed, neuronal cell bodies containing VIP are seen in the paracervical ganglia of the female genitalia, the para- or intramural bladder ganglia and scattered through the base of the cavernosum body, the neck of the bladder and the prostate. The finding of elevated levels of VIP in the local circulation after induced penile erection in man and mammals and the ability of VIP to relax the detrusor muscle of the bladder suggests that the peptide may be involved in penile erection and bladder relaxation, as does the marked VIP depletion in the penis or bladder in patients suffering from diabetic impotence or bladder instability.