Immunodetection, immunoinhibition, immunoquantitation and biochemical analyses of cytochrome P-450IA1 in tissues of the ratoffceptus during the progression of organogenesis

Polyclonal antibodies raised against the adult form of rat hepatic cytochrome P-450IA1 were used to immunologically detect, inhibit and quantitate an analogous isozymic form(s) in various tissues of the rat conceptus during the progression of organogenesis. Tissues investigated were the embryo proper, the visceral yolk sac and the ectoplacental cone/chorioallantoic placenta. Studies were performed on conceptuses from day 10 (day of conception = day 0) to day 14 of gestation. Ethoxyphenoxazone deethylation, benzo[a]pyrene (BaP) hydroxylation, and ring- and N-hydroxylation of 2-acetylamino-fluorene (AAF) were utilized in assessments of cytochrome P-450IA1-dependent monooxygenase activities during the same gestational period. In untreated conceptuses, cytochrome P-450IA1 could not be detected immunologically in any of the three tissues at any stage of gestation investigated. The deethylation reaction was quantifiable in embryos and yolk sacs of untreated conceptuses, but was not inhibited by cytochrome anti-P-450IA1 antibodies, alpha-naphthoflavone or metyrapone. Treatment of pregnant rats with 40 mg/kg of 3-methylcholanthrene 48 hr prior to removal of the conceptuses resulted in marked increases in measured enzymatic activities as well as in readily immunodetectable cytochrome P-450IA1. Inducibility for the deethylase was greatest in the visceral yolk sac (3-8x), was evident in the embryo proper (2-3x) but was minimal in the ectoplacental cone (1.5-2x). Much greater induction (up to 70x) was observed with BaP and AAF as substrates. Induced activities were inhibited effectively (70-100% inhibition) by cytochrome anti-P-450IA1 antibodies and by alpha-naphthoflavone but not by metyrapone. Inducibility increased as a function of gestational age in the ectoplacental cone/chorioallantoic placenta but reached maxima on day 12 in the embryo and visceral yolk sac. A good correlation between antibody/alpha-naphthoflavone-inhibited enzymatic activities and quantities of immuno-detectable cytochrome P-450IA1 was also apparent. The results indicate that cytochrome P-450IA1, or a very closely related isoform(s), is both inducible and enzymatically functional in tissues of the conceptus throughout organogenesis and have important implications for the potential effects of bioactivatable proteratogens.

Immunohistochemical distribution and partial characterization of FLFQPQRFamidelike peptides in the central nervous system of rats

Two peptides that are structurally related to the molluscan tetrapeptide Phe-Met-Arg-Phe-NH2 (FMRF-NH2) were recently isolated from bovine brain extract (Yang et al.: Proc. Natl. Acad. Sci. USA 82:7757-7761, '85). These peptides have an attenuating effect on morphine-induced analgesia when injected intracerebroventricularly in rats. Antisera against the two peptides--an octapeptide, Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F8F-NH2), and an octadecapeptide, Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe- NH2 (A18F-NH2)--were raised in rabbits and characterized with standard radioimmunoassay and immunohistochemical blocking controls. This study was aimed at localizing neurons in the rat brain that contain immunoreactivity for these peptides. Cryostat sections of normal and colchicine-treated Sprague-Dawley rat brains were incubated with the specific antisera and the immunoreactivity was visualized by the PAP or the FITC method. Immunoreactive neurons were detected in the hypothalamus and nucleus of the solitary tract. Relatively dense networks of fibers and terminals were observed in the lateral parabrachial nucleus and in the nucleus of the solitary tract. Fibers and terminals were also seen in the lateral septum, amygdala, hypothalamus, neurohypophysis, thalamus, periaqueductal gray, and several medullary nuclei. In these areas the immunoreactivity was abolished when the antisera were incubated with the corresponding synthetic peptides F8F-NH2 and A18F-NH2. Preincubation of the antisera with neuropeptide Y (NPY) did not affect the staining. The results suggest that there are neurons in the rat brain that contain F8F-NH2- and A18F-NH2-like peptides. The neuronal system described here may have a role in the regulation of autonomic functions, such as hypothalamic control and respiratory functions. The neuronal connections of the cells containing F8F-NH2- and A18F-NH2-like peptides remain to be studied.

Rat brain regional distribution and spinal cord neuronal pathway of FLFQPQRF-NH2, a mammalian FMRF-NH2-like peptide

Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-NH2) is a peptide, originally detected by FMRF-NH2 antisera, and subsequently isolated from bovine brain. Using a specific radioimmunoassay for F-8-F-NH2, we have examined the regional distribution and characteristics of F-8-F-NH2 immunoreactivity (IR) in rat brain, spinal cord and pituitary gland. In CNS, F-8-F-NH2-IR is highly concentrated in the spinal cord, hypothalamus and pons-medulla (368, 202 and 136 fmol per mg protein, respectively); lowest values are in the cortex and hippocampus. A modest rostrocaudal gradient of F-8-F-NH2-IR was observed; levels in the sacral cord are 50% higher than in the cervical cord. Dorsal cord content is 8 times higher than in the ventral cord. Dorsal rhizotomy failed to change F-8-F-NH2-IR in the affected regions of the spinal cord while significantly reducing substance P levels. F-8-F-NH2-IR was significantly decreased caudal to a spinal transection, indicating the presence of a descending pathway within the spinal cord. The highest concentration of F-8-F-NH2-IR (1008 fmol per mg protein) was found in the neurointermediate lobe of the pituitary, while no F-8-F-NH2-IR could be detected in the anterior lobe. Immunohistochemically, F-8-F-NH2-IR was confined to nerve terminal-like structures in the neural lobe. The anterior and intermediate lobes were devoid of immunoreactive structures. HPLC characterization of F-8-F-NH2-IR in the dorsal spinal cord, medulla-pons and pituitary revealed one major immunoreactive peak which is more hydrophobic than bovine F-8-F-NH2. In addition to this material, the hypothalamus was found to contain another, more abundant F-8-F-NH2-immunoreactive peak. Analysis of F-8-F-NH2-IR from posterior pituitary with various antisera having differing affinities for F-8-F-NH2 and gamma 1-MSH indicates that the F-8-F-NH2-IR of rat pituitary is not due to gamma 1-MSH. The high concentration of F-8-F-NH2-like peptide in the dorsal spinal cord supports a role in mediating nociceptive transmission while the localization of F-8-F-NH2-IR in the posterior pituitary suggests an additional autonomic or endocrine function.

IgG from antiserum against endogenous mammalian FMRF-NH2-related peptides augments morphine- and stress-induced analgesia in mice

Two mammalian FMRF-NH2-like peptides have been isolated from bovine brain; an octapeptide with the structure Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-F-NH2) and an octadecapeptide, Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe- NH2 (A-18-F-NH2). In the present study determinations were made of the effects of intracerebroventricular administration of IgG prepared from antisera raised against these peptides on nociception and morphine- and immobilization-induced opioid analgesia in mice. Both F-8-F-NH2-IgG and A-18-F-NH2-IgG antisera increased nociception (thermal response latency) and significantly augmented morphine- and immobilization-induced analgesia in a naloxone reversible manner, with F-8-F-NH2-IgG antisera having a greater effect than A-18-F-NH2-IgG antisera. These results provide further evidence that mammalian FMRF-NH2-like peptides function as endogenous opiate antagonists and have a role in the mediation of antinociception.

[Clinical and radiological diagnosis of Fanconi's anemia]

This paper reported 4 cases of Fanconi's anemia, which is a rare disease usually seen in children under 10 years of age. Its clinical features comprise familial pancytopenia, hypoplasia of bone marrow, and conspicuous megakaryophthisis, with multiple malformations predominantly occurring in the skeleton and kidney. Some cases may be associated with abnormalities of the chromosome.

Virus-induced polyclonal cytotoxic T lymphocyte stimulation

Infections with a variety of viruses (lymphocytic choriomeningitis (LCMV), murine cytomegalovirus, Pichinde virus, vaccinia virus) stimulated C57BL/6 mice to generate allospecific CTL coincidental with the generation of virus-specific CTL. In C57BL/6 (H-2b) mice, LCMV-induced CTL with reactivity against cells from mice bearing gene products of the d, f, k, p, q, and s but not the b MHC loci. Studies with congenic mouse strains indicated that the MHC loci coded for the target of the allospecific killer cells. The targets of the allospecific CTL were further identified as class I MHC Ag by three criteria: 1) target cells from congenic strains of mice differing from effector cells only in the expression of class I Ag were sensitive to lysis; 2) fibroblasts expressing low levels of class I Ag were resistant to lysis but were rendered sensitive after treatment with IFN-beta, which induced higher expression of class I Ag; and 3) antibody specific for class I Ag expressed on the target cell blocked killing. Studies with congenic mouse strains also suggested that the ability to generate high levels of the virus-induced allospecific killer cells was also under MHC regulation, as H-2b mice generated high levels and H-2k mice low levels of the allospecific CTL. Both C3H/St and C57BL/6 mice immunized against LCMV developed detectable LCMV-specific CTL when later challenged with either murine cytomegalovirus, Pichinde virus, or vaccinia virus, indicating that a virus infection can stimulate the reappearance of memory CTL. Cold target competition studies indicated no cross-reactivities between these viruses or allogeneic cells at the CTL level. Both the allospecific CTL and the reactivated LCMV-specific CTL were found in blast-size lymphocyte preparations. Spleen cells taken from LCMV-infected C57BL/6 mice 5 days post-infection spontaneously generated into allospecific and virus-specific CTL after 2 days of culture. The generation of both was dependent on the presence of supernatant factors produced only in the presence of L3T4+ cells. These factors activated allospecific CTL in spleen cells from virus-primed mice but not from control mice. We suggest that lymphokines produced as a consequence of virus infection may act to stimulate the proliferation and activation of CTL not specific to the challenge virus, resulting in a virus-induced polyclonal CTL stimulation.

Virus-induced polyclonal cytotoxic T lymphocyte stimulation

Infections with a variety of viruses (lymphocytic choriomeningitis (LCMV), murine cytomegalovirus, Pichinde virus, vaccinia virus) stimulated C57BL/6 mice to generate allospecific CTL coincidental with the generation of virus-specific CTL. In C57BL/6 (H-2b) mice, LCMV-induced CTL with reactivity against cells from mice bearing gene products of the d, f, k, p, q, and s but not the b MHC loci. Studies with congenic mouse strains indicated that the MHC loci coded for the target of the allospecific killer cells. The targets of the allospecific CTL were further identified as class I MHC Ag by three criteria: 1) target cells from congenic strains of mice differing from effector cells only in the expression of class I Ag were sensitive to lysis; 2) fibroblasts expressing low levels of class I Ag were resistant to lysis but were rendered sensitive after treatment with IFN-beta, which induced higher expression of class I Ag; and 3) antibody specific for class I Ag expressed on the target cell blocked killing. Studies with congenic mouse strains also suggested that the ability to generate high levels of the virus-induced allospecific killer cells was also under MHC regulation, as H-2b mice generated high levels and H-2k mice low levels of the allospecific CTL. Both C3H/St and C57BL/6 mice immunized against LCMV developed detectable LCMV-specific CTL when later challenged with either murine cytomegalovirus, Pichinde virus, or vaccinia virus, indicating that a virus infection can stimulate the reappearance of memory CTL. Cold target competition studies indicated no cross-reactivities between these viruses or allogeneic cells at the CTL level. Both the allospecific CTL and the reactivated LCMV-specific CTL were found in blast-size lymphocyte preparations. Spleen cells taken from LCMV-infected C57BL/6 mice 5 days post-infection spontaneously generated into allospecific and virus-specific CTL after 2 days of culture. The generation of both was dependent on the presence of supernatant factors produced only in the presence of L3T4+ cells. These factors activated allospecific CTL in spleen cells from virus-primed mice but not from control mice. We suggest that lymphokines produced as a consequence of virus infection may act to stimulate the proliferation and activation of CTL not specific to the challenge virus, resulting in a virus-induced polyclonal CTL stimulation.

Attitudes towards psychoses and psychotic patients in Beijing

The issue of public health education regarding mental illnesses has been relatively low profile in the People's Republic of China. A questionnaire study was carried out on 3,028 lay members of the Beijing population to ascertain their knowledge of opinions concerning and attitudes towards the mentally ill. Very few subjects had systematic knowledge about mental illness and nearly half had no acquired knowledge at all. On the whole they were sympathetic towards the mentally ill and towards provision of high quality mental health care. Despite this sympathy a small proportion still attributed mental illness either to 'ghosts', 'retribution for ancestors' evil deeds' or 'bad thoughts'. Superstitious ideas were clearly related to low educational attainment. The attitudes of family members of psychotic patients were explored in greater detail.

Biochemical characterization of FMRF-NH2-like peptides in spinal cords of various mammalian species using specific radioimmunoassays

Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-F-NH2) and Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe-NH2 (A-18-F-NH2), originally detected by FMRF-NH2 antiserum and subsequently isolated from bovine brain, were found to be highly localized in the bovine spinal cord. Using specific radioimmunoassays coupled with HPLC, F-8-F-NH2 and A-18-F-NH2 immunoreactivities in spinal cord of bovine, rat, mouse, guinea pig and human were studied. One major F-8-F-NH2 immunoreactivity was detected in the spinal cord of every species except in human, however, the retention time of F-8-F-NH2 immunoreactivity appears to vary from species to species. In the human spinal cord three major F-8-F-NH2 immunoreactivities are detected and one of them was eluted in the position of F-8-F-NH2. Two major A-18-F-NH2 immunoreactivities were detected in every species except guinea pig; one of these immunoreactivities can be identified as F-8-F-NH2 immunoreactivity due to the high affinity of the A-18-F-NH2 antiserum to F-8-F-NH2. F-8-F-NH2 and A-18-F-NH2 immunoreactivities can also be clearly detected by FMRF-NH2 antiserum, however, the quantities of these peptides can be grossly underestimated by the FMRF-NH2 RIA. These results confirm that there is a novel system of FMRF-NH2-like peptides in mammalian CNS and some of them are more closely related to the bovine peptides, F-8-F-NH2 and A-18-F-NH2 than to FMRF-NH2.

Cytochrome P-450-dependent biotransformation of a series of phenoxazone ethers in the rat conceptus during early organogenesis: evidence for multiple P-450 isoenzymes

Using highly sensitive probe-substrate analyses, investigations of drug biotransformation in tissues of the rat conceptus during an early stage of organogenesis revealed that three separate tissue components each contained P-450 isozymes capable of catalyzing the monooxygenation of foreign organic chemicals. Tissues of the embryo proper contained constitutive P450(s) that catalyzed readily measurable O-depentylation and O-debenzylation of pentoxyphenoxazone and benzyloxyphenoxazone, respectively, but no measurable O-demethylation of methoxyphenoxazone and barely detectable O-deethylation of ethoxyphenoxazone. Higher specific activities for the O-depentylation and O-debenzylation reactions were measured in preparations of the yolk sac and this organ also appeared to contain constitutive P450(s) for the readily detectable O-deethylation of ethoxyphenoxazone. The O-demethylation of methoxyphenoxazone could not be detected in the yolk sac. Only the O-debenzylation reaction could be detected in tissues of the ectoplacental cone. Treatment of conceptuses in utero with 3-methycholantherene (MC) resulted in significantly increased rates of O-deethylation reactions in preparations of yolk sac and embryo but not ectoplacental cone. Demethylation was not detectable in the same preparations. Treatment with phenobarbital, pregnenolone-16 alpha-carbonitrile, or isosafrole produced no observable effect on any of the reactions studied. Carbon monoxide (CO:O2 = 80:20 versus N2:O2 = 80:20) markedly inhibited all reaction rates and inhibition could be reversed by replacement of CO with N2. Deethylation and debenzylation were inhibited by anti-P450IA1 IgG after MC induction but were not affected by the same IgG fraction in untreated conceptuses. Depentylation reactions were not inhibited by anti-P450IA1 or anti-P450IIB1/2 antibodies under any of the conditions used. Deethylation was strongly inhibited by 1.0 microM 7,8-benzoflavone in tissues from MC-treated but not untreated conceptus. Metyrapone (0.1 mM) failed to significantly inhibit any of the measurable conceptus-catalyzed depentylation reaction. The results indicated the presence of four (or more) functional P450 isozymes in tissues of the conceptus during organogenesis, a constitutive depentylase(s) in the yolk sac and embryo, a constitutive deethylase(s) present in the yolk sac, an MC-inducible deethylase(s) in the embryo and yolk sac, and constitutive debenzylase(s) present in all three tissues. No O-demethylation was detectable in any of the three tissues, even after in utero exposure to inducers.(ABSTRACT TRUNCATED AT 400 WORDS)

Manifestations of cell damage after freezing and thawing

The nature of the primary lesions suffered by cells during freezing and thawing is unclear, although the plasma membrane is often considered the primary site for freezing injury. This study was designed to investigate the nature of damage immediately after thawing, by monitoring several functional tests of the cell and the plasma membrane. Hamster fibroblasts, human lymphocytes, and human granulocytes were subjected to a graded freeze-thaw stress in the absence of cryoprotective compound by cooling at -1 degree C/min to a temperature between -10 and -40 degrees C, and then were either warmed directly in water at 37 degrees C or cooled rapidly to -196 degrees C before rapid warming. Mitochondrial function in the cells was then assessed using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide (MTT), fluorescein diacetate (FDA), colony growth, and osmometric response in a hypertonic solution. Cells behaved as osmometers after cooling at -1 degree C/min to low temperatures at which there were no responses measured by other assays, indicating that the plasma membrane is not a primary site for injury sustained during slow cooling. These results also indicate that the FDA test does not measure membrane integrity, but reflects the permeability of the channels through which fluorescein leaves the cells. Fewer cells could respond osmotically after cooling under conditions where intracellular freezing was likely, implying that the plasma membrane is directly damaged by the conditions leading to intracellular freezing. A general model of freezing injury to nucleated mammalian cells is proposed in which disruption of the lysosomes constitutes the primary lesion in cells cooled under conditions where the cells are dehydrated at low temperatures.

Age-related bidirectional changes in neuropeptide Y peptides in rat adrenal glands, brain, and blood

Age-related changes in neuropeptide Y (NPY) regulation were studied in rat adrenal glands, brains, and blood by radioimmunoassay and biochemical characterization using reversed phase HPLC and gel filtration chromatography. NPY immunoreactivity (pmol/g tissue +/- SEM) in rat adrenal glands increased from 7 +/- 1 (6 weeks old) to 1,500 +/- 580 (69 weeks old). Biochemical characterization by HPLC showed that this increase was due to those of NPY and methionine sulfoxide NPY. In contrast, in rat brain, NPY content decreased in an age-dependent manner specifically in striatum, hippocampus, medulla oblongata, and spinal cord and the sulfoxide form was not detected. In rat blood, the circulating level of NPY was high (3-5 pmol/ml plasma +/- SEM) but did not change significantly with age or by adrenal demedullation. Only a small increase of the sulfoxide form of NPY was observed in aged rat plasma. The age-dependent changes in regulation and modification of NPY in adrenal glands and in specific brain areas may have physiological relevance in the regulation of catecholamine release from adrenal glands and some brain functions during aging.

Rat neuropeptide Y precursor gene expression. mRNA structure, tissue distribution, and regulation by glucocorticoids, cyclic AMP, and phorbol ester

Rat brain neuropeptide Y precursor (prepro-NPY) cDNA clones were isolated and sequenced in order to study regulation of the prepro-NPY gene. Rat prepro-NPY (98 amino acid residues) contains a 36-residue NPY sequence, followed by a proteolysis/amidation site Gly-Lys-Arg, followed by a 30-residue COOH-terminal sequence. The strong evolutionary conservation of rat and human sequences of NPY (100%) and COOH-terminal peptide (93%) suggests that both peptides have important biological functions. In the rat central nervous system, prepro-NPY mRNA (800 bases) is most abundant in the striatum and cortex and moderately abundant in the hippocampus, hypothalamus, and spinal cord. The rat adrenal, spleen, heart, and lung have significant levels of prepro-NPY mRNA. Regulation of the prepro-NPY mRNA abundance was studied in several rodent neural cell lines. PC12 rat pheochromocytoma and N18TG-2 mouse neuroblastoma cells possess low basal levels of prepro-NPY mRNA, while NG108-15 hybrid cells possess high levels. Treatment of PC12 cells with a glucocorticoid such as dexamethasone or elevation of cAMP by forskolin increased the prepro-NPY mRNA level 2-3-fold or 3-10-fold, respectively. In N18TG-2 cells dexamethasone and forskolin synergistically increased prepro-NPY mRNA 7-fold. Treatment of PC12 cells with the protein kinase C activator phorbol 12-myristate 13-acetate alone elevated prepro-NPY mRNA marginally, but the phorbol ester plus forskolin elicited 20-70-fold increases, which were further enhanced to over 200-fold by dexamethasone and the calcium ionophore A23187. These results indicate that NPY gene expression can be positively regulated by synergistic actions of glucocorticoids, cAMP elevation, and protein kinase C activation.

[Carcinoma of the extrahepatic bile duct--report of 13 patients]

13 patients with extrahepatic bile duct carcinoma treated in our institute from 1960 to 1986 are reported. All were proven by pathology. There were 10 moderately differentiated or mucin adenocarcinomas, 2 poorly differentiated and 1 undifferentiated cancers. There were 9 males and 4 females with an average age of 60.6 years. Progressive obstructive jaundice was the most common presenting symptom (11/13). Hepatomegaly was found in 7 patients, distended gallbladder in 4 and gallstone in 2. Before operation, 10 patients were misdiagnosed as hepatitis, cholecystitis or cholelithiasis. During operation, regional lymph node metastasis was observed in the majority of patients. Palliative operation was performed in 10 patients and radical surgery in 3. Three received operation plus postoperative radiotherapy. None survived more than two years. The lesions occurred frequently in the upper bile duct (8 patients). The middle bile duct and diffuse type carcinomas comprised 2 each. One was not recorded clearly. The prognosis is related to the gross type of the tumor and differentiation degree. Finally, carcinogenesis is discussed briefly.

Neuropeptide Y inhibits the nicotine-mediated release of catecholamines from bovine adrenal chromaffin cells

The possible role of neuropeptide Y (NPY) in catecholamine secretion was studied by using bovine adrenal chromaffin cells. NPY produced a concentration-dependent inhibition of nicotine-stimulated norepinephrine and epinephrine release from bovine chromaffin cells with IC50 (concentration of NPY which inhibits 50% of maximum release of catecholamines) values of 1.8 x 10(-9) M and 1.7 x 10(-9) M, respectively. Catecholamine release induced by 56 mM KCl was not inhibited by NPY at these concentrations but was inhibited by high concentration (2 x 10(-6) M) of NPY. This inhibition was not affected by the concentration of nicotine used for catecholamine release or the presence of alpha, beta adrenergic and muscarinic antagonists. A structurally related peptide, human pancreatic polypeptide, showed a similar inhibitory effect on catecholamine release, but peptide YY or avian pancreatic polypeptide had little or no effect. N-propionyl[3H]NPY binds to a single class of saturable binding sites on bovine adrenal medulla membranes with a KD = 0.32 +/- 0.07 nM and Bmax = 63 +/- 16 fmol/mg of protein. The rank order of potency of NPY and other structurally similar peptides to displace N-propionyl[3H]NPY from binding is human pancreatic polypeptide greater than or equal to NPY much greater than peptide YY greater than avian pancreatic polypeptide, and is correlated with their potency to inhibit catecholamine release. These results suggest a modulatory role for NPY through a specific NPY receptor in the secretion of catecholamine from the adrenal.

Neuropeptide Y release from the adrenal medulla after cholinergic receptor stimulation

Peripheral nerves as well as chromaffin cells have been shown to contain neuropeptide Y (NPY), a 36 amino acid peptide that exhibits potent stimulatory actions on vascular smooth muscle. Because NPY-like immunoreactive material (NPY-IR) is stored in chromaffin granules we chose to investigate, using the retrogradely perfused bovine adrenal gland, whether nicotinic cholinergic receptor stimulation results in the secretion of this material. In addition we monitored the release of [Met5]-enkephalin-like immunoreactive material (ME-IR), which has been demonstrated to be released from the bovine adrenal medulla. NPY-IR and ME-IR were measured using antisera prepared from hemocyanin conjugates of the peptides. Increasing concentrations of acetylcholine (1 X 10(-6) M-5 X 10(-5) M), infused in the presence of 1 X 10(-5) M physostigmine, produced significant increases in NPY-IR and ME-IR release. Hexamethonium (5 X 10(-4) M) antagonized the release of both of these substances, whereas atropine (5 X 10(-7) M) did not. The role of the nicotinic cholinergic receptor in this process was established further by examining the effects of 1,1-dimethyl-4-phenylpiperazinium. Increasing concentrations of 1,1-dimethyl-4-phenylpiperazinium (1 X 10(-6) M-5 X 10(-5) M) also stimulated the release of NPY-IR and ME-IR. Analysis of the perfusate by reverse phase liquid chromatography revealed the presence of four peaks of NPY-IR. A major peak coeluted with authentic NPY. These data demonstrate that NPY-IR can be released through stimulation of the nicotinic cholinergic receptor. The adrenal medulla appears to be one of the sources for circulating NPY-IR.

Neural tube defects in Beijing-Tianjin area of China. Urban-rural distribution and some other epidemiological characteristics

Records in the obstetric wards and nurseries of 18 hospitals were reviewed and studied epidemiologically, covering about 210,000 deliveries and 1000 cases of neural tube defects (NTD). All live and still births occurred in the period 1970-84. Following the NTD classification used by Koch (1984), our case series consisted of anencephalus 50.3%, spina bifida 44.2%, and NTD with other system defects 5.5%. Overall NTD prevalence rate at birth was 4 per thousand, obviously higher than those in most other countries. Marked urban-rural differences in NTD prevalence rate at birth were observed. The rate in rural areas after correction for selection bias was still as high as 7.25 per thousand. As compared with cities and suburbs, the relative risk of NTD born to mothers in rural regions was 2.4. The male-to-female ratios were much less than 1 for various kinds of NTD. Looking at the effect of maternal age and birth order simultaneously in 12 different settings, it can be seen that prevalence of NTD was moderately higher among second and third births to women aged less than or equal to 24 and those greater than or equal to 35 years of age.

Distribution and characterization of two putative endogenous opioid antagonist peptides in bovine brain

Highly sensitive radioimmunoassays were developed and used in studies of the distribution and chromatographic properties of two mammalian FMRF-NH2-like peptides recently isolated from bovine brain; an octapeptide with the structure Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-F-NH2) and on octadecapeptide, Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe-NH2 (A-18-F-NH2). F-8-F-NH2 and A-18-F-NH2 immunoreactivities are unevenly distributed in bovine brain. The highest concentrations (pmol g-1) of F-8-F-NH2 and A-18-F-NH2 are found in dorsal spinal cord (9.8 and 16.4 respectively), periaqueductal grey (8.6 and 6.8) and pons medulla (7.0 and 8.9); lowest quantities are in cortex, cerebellum and striatum. HPLC analysis coupled with radioimmunoassay reveals that the major immunoreactivities are identical to synthetic F-8-F-NH2 and A-18-F-NH2 while there are additional immunoreactive materials, distinct from NPY, whose structures still remain to be determined. The enrichment of these peptides in dorsal cord and periaqueductal grey, areas important in opioid-mediated pain perception, suggest that they may play a role in mediating antinociception.

Elevation of arterial pressure in rats by two new vertebrate peptides FLFQPQRF-NH2 and AGEGLSSPFWSLAAPQRF-NH2 which are immunoreactive to FMRF-NH2 antiserum

We found that two recently characterized neuropeptides Phe-Leu-Phe-Gln-Pro-Gln-Arg-Phe-NH2 (F-8-F-NH2) and Ala-Gly-Glu-Gly-Leu-Ser-Ser-Pro-Phe-Trp-Ser-Leu-Ala-Ala-Pro-Gln-Arg-Phe-NH2 (A-18-F-NH2) elevate mean arterial blood pressure (MAP) in conscious, unrestrained rats. The pressor activities of both agents were attenuated, but not abolished, by prior treatment with guanethidine or prazosin. These results suggest that F-8-F-NH2 and A-18-F-NH2 elevate MAP in rats by potentiating the release of catecholamines and by mechanisms independent of catecholamine release.