Crustacean pigment-dispersing hormones: chemistry, distribution and actions.
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Amino Acid Sequence↗
Biomedical subjects
K R Rao
Publications and source records attributed to K R Rao.
Pigment-dispersing hormone-immunoreactive neurons and their relation to serotonergic neurons in the blowfly and cockroach visual system.
The pigment-dispersing hormone (PDH) family of neuropeptides comprises a series of closely related octadecapeptides, isolated from different species of crustaceans and insects, which can be demonstrated immunocytochemically in neurons in the central nervous system and optic lobes of some representatives of these groups (Rao and Riehm 1989). In this investigation we have extended these immunocytochemical studies to include the blowfly Phormia terraenovae and the cockroach Leucophaea maderae. In the former species tissue extracts were also tested in a bioassay: extracts of blowfly brains exhibited PDH-like biological activity, causing melanophore pigment dispersion in destalked (eyestalkless) specimens of the fiddler crab Uca pugilator. using standard immunocytochemical techniques, we could demonstrate a small number of pigment-dispersing hormone-immunoreactive (PDH-IR) neurons innervating optic lobe neuropil in the blowfly and the cockroadh. In the blowfly the cell bodies of these neurons are located at the anterior base of the medulla. At least eight PDH-IR cell bodies of two size classes can be distinguished: 4 larger and 4 smaller. Branching immunoreactive fibers invade three layers in the medulla neuropil, and one stratum distal and one proximal to the lamina synaptic layer. A few fibers can also be seen invading the basal lobula and the lobula plate. The fibers distal to the lamina appear to be derived from two of the large PDH-IR cell bodies which also send processes into the medulla. These neurons share many features in their lamina-medulla morphology with the serotonin immunoreactive neurons LBO-5HT described earlier (see Nässel 1988). It could be demonstrated by immunocytochemical double labeling that the serotonin and PDH immunoreactivities are located in two separate sets of neurons. In the cockroach optic lobe PDH-IR processes were found to invade the lamina synaptic region and form a diffuse distribution in the medulla. The numerous cell bodies of the lamina-medulla cells in the cockroach are located basal to the lamina in two clusters. Additional PDH-IR cell bodies could be found at the anterior base of the medulla. The distribution and morphology of serotonin-immunoreactive neurons in the cockroach lamina was found to be very similar to the PDH-IR ones. It is hence tempting to speculate that in both species the PDH- and serotonin-immunoreactive neurons are functionally coupled with common follower neurons. These neurons may be candidates for regulating large numbers of units in the visual system.(ABSTRACT TRUNCATED AT 400 WORDS)
Amino Acid Sequence↗
Primary structure and relative potency of an analog of beta-PDH (pigment-dispersing hormone) from the crayfish Procambarus clarkii.
A pigment-dispersing hormone (PDH) from eyestalks of the crayfish Procambarus clarkii was purified by gel filtration, cation-exchange chromatography, partition chromatography, and reversed-phase HPLC. Based on automated sequencing and by the identical chromatographic behavior of the native PDH and the synthetic amidated form of the deduced sequence, the primary structure of Procambarus PDH has been established as: Asn-Ser-Glu-Leu-Ile-Asn-Ser-Ile-Leu-Gly-Leu-Pro-Lys-Val-Met-Asn-Glu-Ala- NH2. This peptide differs from beta-PDH of the fiddler crab Uca pugilator at a single position, Glu17 in place of Asp17. Because of this substitution, Procambarus PDH was 4 to 7-fold less potent than beta-PDH in causing pigment dispersion in the erythrophores, leucophores, and melanophores of Uca. In contrast, Procambarus PDH was 4-fold more potent than beta-PDH in eliciting pigment dispersion in the erythrophores of Procambarus. These peptides displayed less marked differences in potency in triggering leucophore pigment dispersion and light-adaptational distal eye pigment movement in Procambarus. These findings indicate that the structural requirements for PDH-receptor interactions vary with the species and with the target cell type within a given species.
Amino Acid Sequence↗
Hypopituitarism following snake bite.
A patient who developed hypopituitarism after viperine envenomation is described. Thrombosis as a part of disseminated intravascular coagulation may have been the cause. Hypopituitarism should be suspected in such cases especially when there is associated acute renal failure.
Adult↗
Response of Ehrlich carcinoma and the small intestine of mouse to combined treatment with chlorpromazine and X-rays.
The effect of combined treatment with chlorpromazine (20 mg/kg body weight) and X-rays at different dose levels was tested on the growth of Ehrlich carcinoma tumor in solid or ascites form in mice. The radiation response of murine gut was also examined separately but under similar experimental conditions. The results obtained indicate that chlorpromazine did not influence the radiation response of all the test systems used in this study. The relevant literature, reviewed in short, shows that the interaction between chlorpromazine and X-rays can result in enhanced radiation response, non-interference or increased radiation tolerance. Therefore any combined effect of chlorpromazine and X-rays observed cannot be generalised.
Animals↗
Crystallization of a calcium-binding lysozyme from horse milk.
Crystals of the calcium-containing lysozyme from horse milk have been grown by precipitation with sodium phosphate. The crystals are orthorhombic space group P2(1)2(1)2(1) with cell dimensions a = 53.2, b = 57.1, and c = 38.2 A and contain a single molecule in the asymmetric unit. The crystals are suitable for high resolution x-ray structural analysis.
Amino Acid Sequence↗
Isolation and identification of a peptide from rat brain which inhibits [3H]TCP binding.
1. A stereospecific radioreceptor binding assay for the phencyclidine analogue [3H]TCP was utilized to screen for inhibitors of binding in extracts of rat brain. 2. Extracts were prepared from rat cortex and hippocampus by methods employing aqueous acid or acidified methanol. Samples were fractionated by reversed phase-HPLC (RP-HPLC) and tested for activity in the radioreceptor assay. Three zones of activity were detected. The most active fraction was further purified by high performance-size exclusion chromatography. 3. Size exclusion chromatography revealed two zones of activity, corresponding to mol. wts of 4000-8000 Da and 1000-2000 Da. Final purification of the lower molecular weight material was achieved by RP-HPLC. 4. Two well-separated peaks were shown to be homogeneous. Their amino acid sequences were determined by automated Edman degradation and data base searching identified these two peaks as the undecapeptide Substance P and its oxidized counterpart (Substance P sulfoxide). 5. Comparative HPLC of synthetic Substance P, or its sulfoxide, as well as spectral analysis confirmed the identity of the isolated peptides. 6. Synthetic Substance P inhibits specific [3H]TCP binding in the radioreceptor assay.
Amino Acid Sequence↗
Response of murine small intestine to combined treatment with fostriecin and X rays.
This radiobiological investigation was based on the measurements of crypt cell survival in mouse small intestine when the animals were injected with a single dose of fostriecin or streptomycin, and subsequently irradiated to the whole body with graded doses of X rays. The experimental data obtained indicated that fostriecin decreased the isoeffect dose to murine intestine by a factor of 2.3, whereas streptomycin did not influence the radiation response. The biological effects of fostriecin on various tumour cell systems in vitro and in vivo are briefly reviewed. The possible basic mechanisms involved in the radiosensitizing action of fostriecin and the implications of these results in the radiation protection of normal tissues are discussed.
Alkenes↗
Histological and functional correlation of thyroid carcinoma by immunohistochemistry.
40 cases of thyroid carcinoma comprising of 22 follicular, 11 papillary, 4 medullary, 2 anaplastic and 1 medullary carcinoma with focal areas of papillary differentiation were selected for this immunohistochemical study for the presence of thyroglobulin, calcitonin and somatostatin. As per the functional classification recommended by Otto L Jungberg, 22 cases were well differentiated, 13 were of intermediate differentiation with 3 poorly differentiated cases. 2 cases of anaplastic carcinoma were negative for all the 3 markers. Correlation between functional classification and histological pattern show 77% of the well differentiated type to be of follicular pattern with the rest consisting of papillary carcinoma. In the intermediate type 38.4% were follicular carcinoma, 15.3% medullary carcinoma and the rest, papillary carcinoma. Poorly differentiated type consisted of 2 medullary carcinomas. Contrary to previous reports, functional differentiation did not always correlate with histological pattern.
Adenocarcinoma↗
Recombinant bovine alpha-lactalbumin obtained by limited proteolysis of a fusion protein expressed at high levels in Escherichia coli.
A cDNA clone containing the entire coding region for bovine pre-alpha-lactalbumin (LA) together with 27 base pairs of 5'-noncoding and 268 base pairs of 3'-noncoding sequences was isolated from a bovine mammary cDNA plasmid library in the Okayama-Berg vector system using a synthetic oligonucleotide probe and sequenced. The coding segment for mature LA was subcloned into the T7 expression system of Studier and co-workers (Studier, F.W., and Moffatt, B.A. (1986) J. Mol. Biol. 189, 113-130; Rosenberg, A.H., Lade, B.N., Chui, D.S., Lin, S.W., Dunn, J.J., and Studier, F.W. (1987) Gene (Amst.) 56, 125-135) and expressed as a 21-kDa fusion protein that consisted of the mature bovine LA sequence connected to the NH2-terminal 50 residues of human cathepsin D by a linker sequence containing protease cleavage sites. This fusion protein was expressed in an insoluble form and accumulated to about 50% of the total bacterial protein within 3 h after induction of T7 RNA polymerase synthesis. The protein was solubilized, purified by gel filtration, and converted to an active form by treatment with mixtures of reduced and oxidized glutathione in the presence of Ca2+. The maximum specific activity of the fusion protein was about 25% of that of native LA, suggesting that the attachment of an NH2-terminal extension sterically hinders but does not prevent the interaction with galactosyltransferase. The extension also does not block the binding of the regulatory Ca2+ ion that is required for folding from the reduced denatured state. Trypsin cleaved the folded fusion protein specifically at a Lys-Glu bond at the junction with the mature LA sequence to give a product indistinguishable in structure and activity from native LA.
Amino Acid Sequence↗
Calcium regulates folding and disulfide-bond formation in alpha-lactalbumin.
Refolding and disulfide bond formation in reduced denatured bovine alpha-lactalbumin is shown to be Ca2+-dependent. Whereas in the absence of Ca2+ only about 2% of the native active protein is regenerated, in the presence of Ca2+, almost quantitative renaturation is obtained. A close coupling between Ca2+-binding and native disulfide bond formation is also indicated by spontaneous disulfide scrambling in the apoprotein in the presence of low concentrations of thiols. This phenomenon is not found in other disulfide-containing proteins including the homologous chicken lysozyme. It is proposed that the alpha-lactalbumin Ca2+-binding site has the in vivo function of imposing Ca2+ regulation on the folding of nascent alpha-lactalbumin and thereby on lactose synthesis.
Animals↗
Combined action of carbaryl and phenthoate on the sensitivity of the acetylcholinesterase system of the fish, Channa punctatus (Bloch).
Inhibition of acetylcholinesterase (AChE) and accumulation of acetylcholine were observed in tissues of fish, Channa punctatus, during carbaryl and/or phenthoate toxicity. Carbaryl in combination with phenthoate exerted synergism on the AChE system during their interaction.
Acetylcholinesterase↗
Long-term experience with 1 per cent topical silver sulphadiazine cream in the management of burn wounds.
Three hundred and forty-two patients with 10-50 per cent body surface area burns were studied prospectively over the 5-year period from 1982 to 1986 for the effectiveness of topical 1 per cent silver sulphadiazine. Various parameters were studied including: (i) healing time of deep partial skin thickness burns, (ii) eschar separation time, (iii) conversion rate of deep dermal burns to full skin thickness burns, (iv) burn wound surface bacterial flora and their changing pattern over the years, (v) incidence of invasive sepsis and (vi) overall mortality. There was a remarkable decrease in the time taken for the healing of deep dermal burns, and the conversion rate of deep dermal burns to full skin thickness was significantly reduced. Eschar separation was delayed considerably. There was a total change in the predominent surface micro-organisms from Staph. aureus, which was predominant in 1982, to pseudomonas species and klebsiella in 1986. Moreover, there was the emergence of a new variety of micro-organism within the last 2 years. The incidence of invasive infection and overall mortality was significantly reduced.
Administration, Topical↗
Delayed hemolytic transfusion reactions in sickle cell anemia.
Delayed hemolytic transfusion reaction (DHTR) developed in three patients with sickle cell anemia seen over an 18-month period at Cook Country Hospital. The DHTR was associated with severe pain crisis, with spherocytic hemolytic anemia, a positive direct antiglobulin test result, previously undetected erythrocyte alloantibodies, and disappearance of Hb A on cellulose acetate electrophoresis. Delayed hemolytic transfusion reactions may be more common than is generally recognized and should be considered when a patient has a sickle cell pain crisis shortly after receiving a transfusion.
Adult↗
Toxic effects of garlic extract and garlic oil in rats.
Significant rise in urea and D-aspartate aminotransferase and inhibition of alkaline phosphatase in serum were observed in rats fed garlic extract (2 ml/100 g body wt, intragastrically) for 10 days. The liver showed histological changes. Garlic oil feeding (10 mg/100 g body wt, intragastrically) after 24 hr fasting was found lethal. The cause of death appears to be acute pulmonary oedema. On histological examination, all the organs of the dead rats revealed severe congestion. However, similar feeding of garlic oil was well tolerated by rats in the fed state. Also, 24 hr fasted rats could tolerate this dose of garlic oil, provided they were previously adapted to garlic oil feeding.
Alkaline Phosphatase↗
Isolation of two neuropeptides in the AKH/RPCH-family from horseflies (Diptera).
Two neuropeptides (DCCI and DCCII) in the adipokinetic/red pigment concentrating hormone-family have been isolated and purified from the corpora cardiaca of horseflies (Diptera : Tabanidae). Both peptides were purified by a sequence of three reversed phase-high performance liquid chromatographic steps. Amino acid analysis of the purified peptides indicated the following composition for DCCI: Glx(l), Gly(1), Leu(1), Phe(1), Pro(1), Thr(2) and for DCCII: Glx(1), Gly(2), Leu(1), Phe(1), Pro(1), Thr(2), and Tyr(1). Photodiode array ultraviolet spectroscopy indicated the presence of tryptophan in both DCCI and II. Both DCCI and II had red pigment concentrating hormone activity in the crab, Uca pugilator.
Amino Acids↗
Sickle cell heart disease. Two-dimensional echo and Doppler ultrasonographic findings in the hearts of adult patients with sickle cell anemia.
Sickle cell anemia (SCA) is a commonly diagnosed condition in the black population in the United States. With better medical management, patients with SCA are living longer and what were previously uncommon sequelae are being recognized frequently, including those involving the cardiovascular system. Previous reports on the cardiovascular effects of SCA have focused predominantly on children, but the conclusions remain controversial. To study this question further, 40 adult patients with documented SCA were examined using two-dimensional and Doppler cardiac ultrasound. Valvular structures were normal despite an increased incidence of flow murmurs. Abnormalities were found more frequently in the left heart than the right, as manifested primarily by increased left ventricular mass, and left ventricular and left atrial dilatation with preservation of systolic function. Pulmonary hypertension, which was present in two thirds of the sample, was minimal to moderate as assessed by our Doppler technique. The effects of SCA on the heart seem to be minimal and similar to those of other anemias, predominantly confined to the left atrium and ventricle with passive elevation of pulmonary pressures. Clinical murmurs were most often physiologic; there was no association with myxomatous valvular degeneration or mitral valve prolapse.
Adult↗
Pigment-dispersing hormones: a novel family of neuropeptides from arthropods.
This report summarizes recent work on the chemistry and structure-activity relationships of crustacean chromatophorotropic pigment-dispersing hormones (PDHs) and the identification of structurally related peptides from insects. So far, the primary structures of crustacean alpha-PDH and beta-PDH and of a pigment-dispersing factor (PDF) from the grasshopper Romalea microptera have been deduced. Additionally, 17 of the 18 residues of a PDF from the cricket Acheta domesticus were identified. In the PDH/PDF family, the chain length (18 residues), terminal residues (N-terminal Asn and C-terminal Ala-NH2), and at least 50% of the amino acid sequence appear to be conserved. The functions of these peptides in insects are unknown. Detailed studies of structure-activity relationships of crustacean PDHs have been conducted, leading to the tentative identification of the message sequence, preparation of hyperpotent oxidation-resistant analogs, and synthesis of bioactive tyrosinated analogs for radioiodination. Antisera were raised against PDHs, and immunoreactive soma and fibers have been localized in the crustacean eyestalk neurosecretory system. This progress is expected to stimulate more intensive research on the PDH family.
Amino Acid Sequence↗