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H Y Yang

Publications and source records attributed to H Y Yang.

At least 145 records · Page 8Linked to original sources
PubMed1988

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.

Adrenal Glands↗
PubMed1988

[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.

Adenocarcinoma↗
PubMed1988

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.

Adrenal Glands↗
PubMed1988

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)

Animals↗
PubMed1987

A genetic analysis of clubfoot in Hawaii.

The roles of major genes and multifactorial inheritance in the etiology of clubfoot (talipes equinovarus) were investigated based on 365 nuclear families consisting of three major racial groups of Hawaiians, Caucasians, and Orientals in Hawaii. Complex segregation analysis was employed using the mixed model with four parameters: major gene displacement (t), degree of dominance (d), gene frequency (q), and heritability (H). Heterogeneity was evident among the racial groups in the pattern of segregation of clubfoot. The most plausible genetic model is the presence of major gene effects with the multifactorial component for the Hawaiian and Caucasian groups, whereas no major gene action is evident for the Oriental group.

Asian People↗
PubMed1987

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.

Animals↗
PubMed1987

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.

Adult↗
PubMed1987

Age- and function-related change in the quantity of high mobility group protein in chick oviduct.

We describe the investigation of the content of chromosomal high-mobility group 1 (HMG1) protein in three cellular fractions (cytosol, microsomal, and nuclear) of the magnum and shell gland of young and aged hen oviducts. In the magnum of the aged hen oviduct, the amount of the HMG1 protein (microgram protein/mg DNA) in the three fractions was 9.3 +/- 1.1, 0.18 +/- 0.03, and 2.4 +/- 0.4, respectively. Whereas the values were 11 +/- 1.2, 0.27 +/- 0.08, and 4.2 +/- 0.4, respectively, for the young hen. 12, 50, and 43% less were found in the aged hen magnum. In the shell gland of the functionally active hen oviduct, the protein in the three cellular fractions was 8.6 +/- 1.05, 0.42 +/- 0.06, and 3.9 +/- 0.55, respectively. In the shell gland of the functionally inactive aged hen, the values were 8 +/- 1.05, 0.28 +/- 0.09, and 0.85 +/- 0.12, and in the inactive shell gland of the young hen, they were 7.6 +/- 1.0, 0.27 +/- 0.09, and 1.75 +/- 0.22, respectively. The most significant difference was in the nuclear fraction, where the HMG1 protein in the functional hen shell gland was 123-359% higher than that of the inactive ones.

Aging↗
PubMed1987

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.

Acetylcholine↗
PubMed1987

Regional differences of effects of ethanol on canine blood vessels.

In vitro effects of ethanol (0.1-2.0%,v/v) on canine vasculer smooth muscle were studied. Ethanol dose-dependently produced inhibition in both the amplitude and frequency of the spontaneous rhythmic activity of the canine hepatic portal vein, and at concentration of 1.0 +/- 0.2% completely abolished the spontaneous activity. Ethanol evoked dose-dependent constriction, rather than dilatation, in all vascular smooth muscles tested, including femoral, renal, common carotid, and pulmonary arteries, and external jugular, splenic, pulmonary, femoral, renal, and hepatic portal veins. The vasoconstriction effect of ethanol was much stronger on arteries than on the corresponding veins. Based on the contractile tension developed by ethanol, the femoral artery or the external jugular vein appeared to be most sensitive to ethanol among the arteries or veins preparations tested. The present results suggested that ethanol, depending on concentration, may either enhance or decrease excitability of vascular smooth muscles. There were also regional differences of effects of ethanol on canine blood vessels.

Animals↗
PubMed1987

Neuroanatomy of morphine-modulating peptides.

Antisera against two mammalian peptides related to the molluscan cardioexcitatory peptide Phe-Met-Arg-Phe-NH2 were used to locate immunoreactive neurons in the rat brain, nerve fibres and terminals in the spinal cord, sympathetic ganglion cells and adrenal chromaffin cells. Immunoreactivity for the newly characterised octa- and octadecapeptide was detected in nerve cell bodies in the hypothalamic area, including parts of the dorsomedial, periventricular and paraventricular nuclei, and in the nucleus tractus solitarii. Nerve terminals in the superficial laminae of the spinal cord were also immunoreactive for these peptides, while the sensory ganglia were nonreactive. Some principal ganglion cells in the superior cervical ganglia exhibited bright immunofluorescence for the peptides, and a few adrenal medullary cells were immunoreactive. The presence of these peptides in the substantia gelatinosa of the spinal cord suggests that they may be involved in sensory neurotransmission, especially in the mechanisms mediating pain. In the hypothalamo-hypophysial system these peptides may be involved in the regulation of hormonal systems. They may also act as co-transmitters in the sympathetic nervous system.

Adrenal Medulla↗
PubMed1986

Changes in dynorphin, enkephalin and cholecystokinin content of hippocampus and substantia nigra after amygdala kindling.

Amygdaloid kindling of rats produced an increase in hippocampal Met5-enkephalin-Arg6-Gly7-Leu8 and cholecystokinin immunoreactivities and simultaneously a decrease in dynorphin A1-8 content. In substantia nigra Met5-enkephalin-Arg6-Gly7-Leu8 was increased and no change was observed in dynorphin A1-8 content. These data suggest that specific alterations of neuropeptides in limbic and extrapyramidal circuits are prominent manifestations of the kindling process or kindled seizures.

Amygdala↗
PubMed1986

Analgesic activity and release of [MET5]enkephalin-Arg6-Gly7-Leu8 from rat spinal cord in vivo.

Rat spinal cord contains the opioid peptide including [Met5]enkephalin-Arg6-Gly7-Leu8 (YGGFMRGL) and a higher molecular weight (HMW) immunoreactive peptide which is an N-terminal extended molecular form of YGGFMRGL. Since a high proportion of tissue immunoreactivity resides in the HMW component we have determined whether this form is released during perfusion of the spinal cord subarachnoid space in vivo while (1) electrically stimulating the sciatic nerves bilaterally or (2) superfusing with substance P. We have found that YGGFMRGL and the HMW immunoreactivity are released by both types of stimuli. The HMW material appeared to be the more stable of the two species of immunoreactivity; its presence in the superfusate was more consistently observed than that of YGGFMRGL itself. Injection of YGGFMRGL into the spinal subarachnoid space in chronically catheterized rats produced a suppression of the tail-flick response. This effect of YGGFMRGL was reversed by naloxone suggesting an action mediated by spinal opiate receptors. These data suggest that YGGFMRGL plays an integral role in the neurotransmission process between spinal neurons storing enkephalin and other neurons. The possibility that enkephalin-mediated neurotransmission includes multiple chemical signals can be entertained.

Analgesics↗
PubMed1986

Peripheral and central origin of Phe-Met-Arg-Phe-amide immunoreactivity in rat spinal cord.

Phe-Met-Arg-Phe-amide immunoreactivity (FMRF-NH2-IR) is highly concentrated in the dorsal horn of rat spinal cord, and particularly in nerve terminals of lamina I. In order to establish the location of the cell bodies of the lamina I terminals containing FMRF-NH2-IR, we measured by radioimmunoassay the FMRF-NH2-IR in sensory ganglia and in spinal roots. FMRF-NH2-IR was found in both tissues, and reverse-phase HPLC analysis revealed that both tissues contain the same molecular forms that are also present in the spinal cord. Lumbo-sacral rhizotomy induced a 50% decrease of FMRF-NH2-IR in the lumbar segment of the spinal cord suggesting that at least a portion of the FMRF-NH2-IR present in this tissue is of peripheral origin. Transection of the spinal cord at the midthoracic level induced a 20-50% decrease of FMRF-NH2-IR in the lumbar segment of the spinal cord suggesting also the presence of FMRF-NH2-IR in descending pathways.

Animals↗