The effect of environmental factors of the coking plant on the enzymatic activity of rabbit oral mucosa.

Histochemical methods were used to investigate the activities of some intracellular enzymes in the oral mucosa of the rabbits which had been kept in selected work-stands of a coking-plant for 3 months. The findings were compared with the results for the enzymatic activity of the oral mucosa of control rabbits. The epithelium of the oral mucosa of the experimental rabbits was found to be proliferated acanthotically; moreover, there occurred some other morphological changes of the mucosa which often resembled precancerous states of leukoplakia type. In comparison with the control group, the activities of the studied enzymes, i.e. reduced NAD dehydrogenase (NADD), glucose-6-phosphate dehydrogenase (G6PD), lactate dehydrogenase (LDS), succinate dehydrogenase (SD), cytochrome oxidase (CO), and phosphorylase a+b in the epithelium and the connective-tissue cells of the studied mucosa of the experimental animals were as a rule markedly lowered, this decline being especially pronounced for the three last-mentioned enzymes. It was only the proliferating stratum basale of the experimental rabbit epithelium that frequently exhibited enhanced activities of NADD and LDS. Besides, the activities of NADD, G6PD and LDS were of a markedly diverse intensity in the cells of the chaotically proliferating stratum spinosum of the experimental rabbit mucosa. The results point to the noxious modifying effect of chemical and physical agents of the investigated environment on the oral mucosa of the animals studied.     

The activity of some intracellular oxidative enzymes in the thyroid follicular epithelium of Xenopus laevis Daud. in experimental long-term hypokinesia.

Histoenzymological methods were applied to examine the activities of previously little studied intracellular oxidative enzymes in the cells of the thyroid follicular epithelium of Xenopus laevis Daud. specimens kept in aquarium. Succinate, lactate, alpha-glycerophosphate, glucose-6-phosphate and reduced NAD and NADP dehydrogenases and cytochrome oxidase were studied. In comparison with other chordate species a very strong activity was revealed particularly by lactate dehydrogenase. The data obtained suggest that the metabolism in thyroid cells of the motionless Xenopus is based on glycolysis mainly.     

Activities of oxidative enzymes in thyroid follicles of Xiphophorin fishes.

The activity of some intracellular oxidative enzymes was studied histochemically in the cells of the thyroid follicles of teleost fishes of the genus Xiphophorus. The experimental material consisted of animals of the red swordtail and Mexican swordtail breeds of Xiphophorus helleri and of melanotic Xiphophorus maculatus fishes. Observations were carried out on adult specimens of both sexes, including pregnant femals of Mexican swordtail. Moreover, immature Mexican swordtails of both sexes were examined. Thyroid follicles were found to be present in the subpharyngeal region of all fishes studied. The distribution of these follicles as well as their number and form depended on sex, age and on the analysed stage of prenancy. A smaller number and size of thyroid follicles were characteristic of immature specimens, whereas they were most numerous in the thyroids of pregnant fishes. The follicles were arranged in characteristic dense aggregations, especially in the melanotic platyfish. The follicular eipthelium in the fishes under study was usually cubical, but pregnant and non-pregnant adult females also contained a considerable number of larger follicles with flattened epithelium. Besides, thyroid follicles of multilayer epithelium were rather frequently encountered, especially in male fishes, irrespective of their age. The thyroid follicle cells of these fishes demonstrated invariably high activities of reduced NAD and NADP dehydrogenases and of beta-hydroxybutyrate dehydrogenase, and a low activity of succinat dehydrogenase. The intensities of alpha-glycerophosphate and lactate dehydrogenases and of cytochrome oxidase varied with sex, age and breed of the studied fishes. The immature and pregnant fishes showed the most clearly pronounced differences in the intensity of enzymic activity, the thyroid follicles of immature specimens revealing a high activity of lactate dehydrogenase and low activity of cytochrome oxidase, an inverse picture being seen in pregnant fishes. The adult forms of both sexes exhibited an enhanced activity of cytochrome oxidase and a decline in that of lactate dehydrogenase. The observed differences in the intensities of enzymic acitivities in the thyroids of the studied fishes are related with functions of this gland which in the period of growth are different from those in the period of sexual maturity, and certainly also with individual metabolic characteristics of the studied fishes.     

Histochemical studies of several "K"-cell enzymes in guinea pig thyroid glands]

The thyroid gland of guinea pigs were studied morphologically. Histochemical methods were used for detection of lactate dehydrogenase, succinic dehydrogenase, cholinesterase, alkaline phosphatase and acid phosphatase. The distribution of "C"-cells in normal thyroid glands was proved to be uneven. In the center of the gland they were more numerous. For statistical investigations the method of silver impregnation of "C"-cells is more practicable, since they can not be obviously distinguished from acinar cells on the basis of glycerophosphate dehydrogenase only. The activity of cholinestarase in "C"-cells and in some other cells of folliculi epithelium is very high. A supposition is made that there exist two kinds of the follicular lining thyrocytes, having different histochemical properties and histogenesis as well.     

Oxidative enzymes in the pancreatic islets of normal and obese-hyperglycemic mice

Summary Histochemical data are presented concerning distributions of succinic dehydrogenase (SD), lactic dehydrogenase (LD), diphosphopyridine nucleotide diaphorase (DPND), triphosphopyridine nucleotide diaphorase (TPND) and glucose-6-phosphate dehydrogenase (G-6-PD) in the pancreas from the American variety of obese-hyperglycemic mice (AO-mice) and their lean litter mates (AN-mice).A high LD activity was found in the exocrine parenchyma, while the reaction in the islet tissue and the duct epithelium was only weak. A considerable reaction for DPND was noted throughout the pancreas. SD activity was slightly more pronounced in the acinar tissue and duct epithelium as compared to the islet tissue, where only a moderate activity appeared. Strong reactions for TPND and G-6-PD were found in the islet cells and duct epithelium, while the activity in the exocrine parenchyma was less pronounced. The hyperactive islet B cells in the AO-mice showed no obvious differences in enzyme activity and distribution compared to that of the AN-mice. The enzyme pattern of the A cells could not be clearly distinguished from that in the B cells.The results suggest the existence at least in the B cells of the mice islet tissue of an active hexosemonophosphate shunt. The probable significance of the hexosemonophosphate shunt for insulin synthesis is briefly discussed.The following abbreviations are used DPN Diphosphopyridine nucleotide - DPND Diphosphopyridine nucleotide diaphorase - DPNH Diphosphopyridine nucleotide, reduced form - EM Embden-Meyerhof - G-6-PD Glucose-6-phosphate dehydrogenase - HMP Hexose monophosphate - LD Lactic dehydrogenase - MTT 3,5-diphenyl-2-(4,5-dimethyl-thiazol-2-yl) tetrazolium bromide - Nitro-BT 2,2-di-p-nitrophenyl-5,5-diphenyl-3,3-(3,3-dimethoxy-4,4-biphenylene)-ditetrazolium chloride - PVP Polyvinyl pyrrolidone (M. W. 11 000) - SD Succinic dehydrogenase - TPN Triphosphopyridine nucleotide - TPND Triphosphopyridine nucleotide diaphorase - TPNH Triphosphopyridine nucleotide, reduced form     

Stereoselective preparation of deuterated reduced nicotinamide adenine nucleotides and substrates by enzymatic synthesis.

A-Side (4-R)-(4-²H)-reduced nicotinamide adenine dinucleotide (NADD) was prepared by a stepwise oxidation of ethanol-d₆ to acetate in the presence of NAD, alcohol dehydrogenase, and aldehyde dehydrogenase. The B-side (4-S) isomer of NADD was prepared using the glucose dehydrogenase activity of glucose-6-phosphate dehydrogenase to oxidize to oxidize glucose-1-d in 40% dimethyl aulfoxide. Subsequent purifieation of the reduced nucleotides was achieved using a column of strongly basic polystyrene macroporous resin (AG MP-1) eluted with 0.2 m LiCl, pH 10, and applying the pooled NADD peak to a polyacrylamide gel (Bio-Gel P-2) column. The final $\text{A}{}_{260}\text{A}{}_{340}$ ratio obtained for these preparations was below 2.3. Preparation of the deuterated reduced nucleotides in this manner allows production of specifieally deuterated substrates by coupled enzymatic synthesis. L-Malate-2-d was prepared by coupled synthesis of A-side NADD to the reduction of oxaloacetate by the A-side enzyme malate dehydrogenase.     

The Lympho-Hemopoietic Organs of the Anadromous Sea Lamprey,Petromyzon marinus. A Comparative Study throughout its Life Span

We have analyzed morphological changes affecting the lympho-hemopoietic organs of the anadromous sea lamprey, Petromyzon marinus throughout its life span. For this analysis, ammocoetes (2–4 years), premetamorphosing lampreys (nearly 5 years), metamorphosing lampreys, macrophtalmia stages (young adults) and parasitic adults (nearly 7 years) were used. The principal lympho-hemopoietic organs in the ammocoete are typhlosole, larval opisthonephros and nephros-associated adipose tissue. After metamorphosis, these organs degenerate, and their lympho-hemopoietic tissue is replaced by dense connective tissue. The supraneural body and to a lesser degree, the definitive opisthonephros, are the main blood-forming organs in adult lampreys. During larval life, lympho-hemopoietic cells appear in the branchial area, associated with pharyngeal epithelium. These loci are not morphologically homologous to the thymus gland of jawed vertebrates. These results are discussed, with special emphasis on the importance of cell microenvironments in eluciding changes in different blood-forming loci throughout the life cycle and their significance for the lamprey's immune capacity.     

Morphological changes in the thyroid gland of rats during various phases of the estral cycle]

The functional state of the thyroid gland and the concentration of thyroid hormones in the peripheral blood were studied in 20 mature female albino rats during their estral cycle. Evaluation of the thyroid functional state was made according to data of histological, morphological (the diameter of folliculi, the height of the thyroid epithelium) and histochemical analysis (determination of NAD and NADP-dehydrogenase, succinatedehydrogenase, lactate dehydrogenase, peroxydase, acid and alkaline phosphatase) as well as biochemical determination of iodine bound with protein (IBP) in the blood plasma and investigation of the ratio of the parameters in question under conditions of the sex cycle. The cyclic changes of the morphological state of the thyroid gland attended by the phases of the estral cycle were revealed. The activation of the organ was observed in proestrus and estrus which was evidenced by high levels of activity of the enzymes under study, high concentration of IBP in the blood and increased height of thyreocytes. A decreased function of the thyroid parenchyma was observed at the period of metaestrus-diestrus.     

Morphological and histochemical studies on the prostate gland of developing and adult Paramphistomum cervi (Digenea: Paramphistomatidae)

Morphological and histochemical studies have been made on the development of the prostate gland of the digenetic trematode, Paramphistomum cervi during the course of its infection in sheep; histochemical characterization of prostate gland secretion in adult worms and its functional relationship with the transport of spermatozoa have also been studied. In 6-wk-old worms, the terminal portion of the male genital duct is formed of what appears to be a syncytial epithelium containing a relatively large number of nuclei compared to the rest of the male duct. Cellular organization of the prostate gland becomes conspicuous in 8-wk-old worms and the prostate gland is fully developed by 16 wk. Two types of prostate gland cells, characteristic of the adult, become distinct in 16-wk-old worms which contain spermatozoa in the lumen of their vas deferens and pars prostatica. Adult worms show two types of prostate gland cells: type I containing mainly glycoprotein and type II mainly phospholipid granules. Weak-to-strong activities of acid phosphatase, alkaline phosphatase, esterase, lipase, adenosine triphosphatase, tetrazolium reductase, NAD-diaphorase, isocitrate dehydrogenase, glyceraldehyde dehydrogenase, α-glycerophosphate dehydrogenase and glucose-6-phosphate dehydrogenase have been observed in the prostate gland. The release of prostate gland secretion and the passage of spermatozoa through the lumen of pars prostatica appear to be synchronized events.     

Suppressive subtractive hybridisation transcriptomics provides a novel insight into the functional role of the hypobranchial gland in a marine mollusc

The hypobranchial gland present in gastropods is an organ whose function is not clearly understood. Involved in mucus production, within members of the family Muricidae it is also the source of the ancient dye Tyrian purple and its bioactive precursors. To gain further insights into hypobranchial gland biology, suppressive subtractive hybridisation was performed on hypobranchial gland and mantle tissue from the marine snail Dicathais orbita creating a differentially expressed cDNA library. 437 clones were randomly sequenced, analysed and annotated and 110 sequences had their functions putatively identified. Importantly this approach identified a putative gene involved in Tyrian purple biosynthesis, an arylsulphatase gene. Confirmation of the upregulation of arylsulphatase in the hypobranchial gland compared to the mantle was demonstrated using quantitative real-time PCR. Other genes identified as playing an important role in the hypobranchial gland were those involved in mucus protein synthesis, choline ester regulation, protein and energy production. This study confirms that the hypobranchial gland is involved in the production of mucus secretion and also identifies it as a site of chemical interaction and biosynthesis. This study lays the foundation for a better understanding of the enzymatic production of Tyrian purple precursors within the gland.     

Sex dimorphism in the thyroid gland. IV. Cytologic aspects of sex dimorphism in the rat thyroid gland

This study was designed to explain whether the sex-dependent differences in the structure of the thyroid gland of adult male and female rats depend on quantitative or qualitative changes in the thyroid follicular cells. Absolute thyroid gland weight was similar in male and female rats, but its relative weight was markedly higher in females however. Volume fractions of epithelium and stroma were higher and that of colloid lower in male than in female rats and the epithelium/colloid ratio was higher in the males. Also absolute the volumes (in mm3) of epithelium and stroma were higher in the males; the thyroid gland of females contained more colloid. The average volume of a thyroid follicular cell, estimated by stereology, was higher in males than in females, although the thyroid gland contained similar numbers of follicular cells in both sexes. Also, thyroid glands from both male and female rats contained a similar DNA quantity. Results of the present study show that the sex dimorphism in the rat thyroid depends upon a difference in the mean volume of thyroid follicular cells, with males having larger cells than females. However, in both sexes the thyroid gland contains a similar quantity of these cells.     

Posttranslational regulation of glucose-6-phosphate dehydrogenase activity in tongue epithelium.

Expression of glucose-6-phosphate dehydrogenase (G6PD) activity is high in tongue epithelium, but its exact function is still unknown. It may be related either to the high proliferation rate of this tissue or to protection against oxidative stress. To elucidate its exact role, we localized quantitatively G6PD activity, protein and mRNA using image analysis in tongue epithelium of rat and rabbit, two species with different diets. Distribution patterns of G6PD activity were largely similar in rat and rabbit but the activities were twofold lower in rabbit. Activity was two to three times higher in upper cell layers of epithelium than in basal cell layers, whereas basal layers, where proliferation takes place, contained twice as much G6PD protein and 40% more mRNA than upper layers. Our findings show that G6PD is synthetized mainly in basal cell layers of tongue epithelium and that it is posttranslationally activated when cells move to upper layers. Therefore, we conclude that the major function of G6PD activity in tongue epithelium is the formation of NADPH for protection against oxidative stress and that diet affects enzyme expression in this tissue.     

Differential effects of short-term β agonist and growth hormone treatments on expression of myosin heavy chain IIB and associated metabolic genes in sheep muscle

Growth hormone (GH) and β agonists increase muscle mass, but the mechanisms for this response are unclear and the magnitude of response is thought to vary with age of animal. To investigate the mechanisms driving the muscle response to these agents, we examined the effects of short-term (6 day) administration of GH or cimaterol (a β2-adrenergic agonist, BA) on skeletal muscle phenotype in both young (day 60) and mature (day 120) lambs. Expression of myosin heavy chain (MyHC) isoforms were measured in Longissimus dorsi (LD), Semitendinosus (ST) and Supraspinatus (SS) muscles as markers of fibre type and metabolic enzyme activities were measured in LD. To investigate potential mechanisms regulating the changes in fibre type/metabolism, expression or activity of a number of signalling molecules were examined in LD. There were no effects of GH administration on MyHC isoform expression at either the mRNA or protein level in any of the muscles. However, BA treatment induced a proportional change in MyHC mRNA expression at both ages, with the %MyHCI and/or IIA mRNA being significantly decreased in all three muscles and %MyHCIIX/IIB mRNA significantly increased in the LD and ST. BA treatment induced de novo expression of MyHCIIB mRNA in LD, the fastest isoform not normally expressed in sheep LD, as well as increasing expression in the other two muscles. In the LD, the increased expression of the fastest MyHC isoforms (IIX and IIB) was associated with a decrease in isocitrate dehydrogenase activity, but no change in lactate dehydrogenase activity, indicating a reduced capacity for oxidative metabolism. In both young and mature lambs, changes in expression of metabolic regulatory factors were observed that might induce these changes in muscle metabolism/fibre type. In particular, BA treatment decreased PPAR-γ coactivator-1β mRNA and increased receptor-interacting protein 140 mRNA. The results suggest that the two agents work via different mechanisms or over different timescales, with only BA inducing changes in muscle mass and transitions to a faster, less oxidative fibre type after a 6-day treatment.     

Oxidative enzymes in the sebaceous glands of the domestic cat

Synopsis The distribution and activities of several oxidative enzymes in various regions of the sebaceous glands of the domestic cat have been studied. The results obtained emphasize the outstanding importance of NADP-linked dehydrogenases for lipogenesis during sebum production. In particular, the reactions for glucose-6-phosphate dehydrogenase were very strong. Among the NAD-linked dehydrogenases investigated, lactate dehydrogenase showed strong activity in the peripheral cells of the sebaceous gland. The reactions for cytochrome oxidase and succinate dehydrogenase were weaker.     

Differences in metabolic response of dog and goat latissimus dorsi muscle to chronic stimulation.

The latissimus dorsi (LD) muscle is considered suitable to assist ventricular mechanical function in either cardiomyoplasty or extra-aortic-assist devices. Such application requires that this mixed-type skeletal muscle be transformed into a fatigue-resistant muscle, the adaptation of which can be elicited by chronic stimulation. In this study the LD muscles of dog and goat were subjected in situ to 12 wk of continuous electrical stimulation through intramuscular electrodes, and their myofibrillar and metabolic adaptations were compared. A gradual increase in the contraction rate of the muscle (in 10 wk from 30 to 80 contractions/min) caused the proportion of immunohistochemically identified type I fibers to increase in dog muscle from 30 to 74% and in goat muscle from 21 to 99%. Correspondingly, the anaerobic-glycolytic activity (fructose-6-phosphate kinase and lactate dehydrogenase activities) decreased by approximately 75% in both dog and goat muscles, whereas the oxidative capacity (fatty acid oxidation and citrate synthase activity) increased two- to threefold in goat LD muscle but remained unaltered in dog LD muscle. Muscular contents of high-energy phosphates and endogenous substrates were maintained, but the L-carnitine content decreased by 43% in both dog and goat. Our data further indicate that, for the monitoring of the metabolic adaptation of skeletal muscle, the ratio of activities of the oxidative and anaerobic-glycolytic pathways (e.g., citrate synthase to fructose-6-phosphate kinase activities) is a useful parameter in both dog and goat.(ABSTRACT TRUNCATED AT 250 WORDS)     

神经肽Y、钙基因相关肽和P物质在甲状腺中的分布及其在甲亢状态下的变化(英文)

以往的研究表明,甲状腺中分布有肽能神经,包括神经肽Y(NPY)能神经、P物质(SP)能神经和脑肠肽(VIP)能神经.这些神经纤维的终末与血管和甲状腺的滤泡接触.一般认为,甲状腺的功能活动主要受下丘脑-垂体-甲状腺轴的调节,有关神经肽的调节,尤其是在甲亢状态下的调节尚不清楚.本研究以SD大鼠为实验动物,通过T4注射建立甲亢动物模型.使用免疫组化技术对NPY、CGRP和SP 在实验与对照动物的分布进行形态学研究,使用放射免疫测定技术对模型动物与对照动物甲状腺中的NPY、CGRP和SP进行定量研究.免疫组化技术发现NPY阳性神经纤维密集环绕小血管,其末端与血管内皮紧密联系,一些NPY阳性神经走行于滤泡间的结缔组织中,其末端与滤泡上皮接触;有SP阳性神经纤维走行于滤泡间的结缔组织中,其末端与滤泡上皮接触;CGRP阳性细胞分布于滤泡间的结缔组织中,或滤泡上皮细胞之间.放射免疫测定表明甲亢大鼠NPY、SP水平高于对照大鼠,CGRP水平低于对照大鼠.结果表明,在甲亢状态下,机体通过血管收缩介质NPY、SP的增多与血管舒张介质CGRP的减少,控制甲状腺素进入血液循环,这是机体在病理过程中的自稳机制之一.     

Morphology of the gills of larval and parasitic adult sea lamprey,Petromyzon marinus L.

The general morphology of the gills is similar in larval (ammocoetes) and parasitic adult sea lampreys, Petromyzon marinus, despite different methods of ventilation necessitated by their feeding habits. The gill lamellae are supported by randomly-distributed pillar cells which enclose blood spaces and collagen columns. The distribution of these cells in lampreys is different from that of higher fishes and it may be inefficient for respiratory exchange. The presence of cytoplasmic microfilaments suggests that these cells have the ability to reduce the lamellar blood spaces through contraction. Marginal channels at the tips of the lamellae are lined only by endothelial cells. The thickness of the water-blood pathway in lampreys falls within the range described for higher fishes, with the most efficient gas exchange likely occurring at the lamellar tips where only a single layer of epithelial cells is present. The abrupt increase in height of the epithelium near the lamellar bases in adults, compared to the gradual transition in height along the lamellae in ammocoetes, is perhaps reflective of higher oxygen requirements during the parasitic stage. The consistent appearance of wide, lateral intercellular spaces within the respiratory epithelium of lampreys indicates possible involvement of these spaces in transport. Mucous secretion appears to be an important function of the superficial platelet cells in ammocoetes. “Mitochondria-rich” and “mitochondria-poor” superficial cells are observed in both ammocoetes and adults, with the mitochondria-rich cells more prevalent toward the lamellar bases. The possibility that at least some of these cells may be involved in absorption is discussed. Mitochondria-rich cells in the interlamellar region are morphologically different in ammocoetes and adults but all possess an abundance of smooth endoplasmic reticulum and hence resemble “chloride cells” of higher fishes. The similarity of these cells in the parasitic adult lamprey to chloride cells of marine fishes may reflect the potential of the adult lamprey to osmoregulate in salt water. A scarcity of these cells in ammocoetes and their resemblance to chloride cells in freshwater fishes may reflect the restriction of larval lampreys to a freshwater habitat.     

Daily variation in antioxidant enzymes lipid peroxidation in thyroid and plasma level thyroxine and triiodothyronine levels of a tropical bird Perdicula asiatica during reproductively active and inactive phases

The aim of this work was to study the variations in the interference of neuroendocrine pineal gland and metabolically active thyroid gland in a tropical bird, Perdicula asiatica. Maximum pineal gland activity (pineal weight and melatonin level), minimum thyroid gland activity (weight, T3/T4 and thymidine kinase activity) along with less oxidative load (MDA level, SOD, CAT and ABTS activity) were observed during reproductively inactive phase (RIP) was observed. Further, a robust and significant rhythmicity was noted in melatonin levels during RIP and RAP, but no significant rhythmicity was noted in T4/T3 level by cosinor analysis. Overall, melatonin and thyroid circadian profile suggested that melatonin might be acting as an antioxidant molecule with time of the day effect in rescuing thyroid gland from free radical load in birds.     

Evidence for a functional role of cholecystokinin receptors in the rat thyroid gland.

The aim of the present study was to examine the role of cholecystokinin (CCK) and/or cholecystokinin receptors subtypes (CCK1R and CCK2R) in the regulation of the thyroid gland structure and function. Animals were autopsied after 6 days of treatment with CCK or CCK receptor-specific antagonists (CCK1a--PD 140,548 or CCK2a--PD 135,158) solely or in combination with CCK. Results suggest that CCK exerts a stimulatory effect on follicular thyroid cells manifested by increased epithelium/colloid volume fraction ratio (E/C). Application of selective antagonists of CCK receptor subtypes has demonstrated that CCK acts through the CCK1 receptor subtype at the level of pituitary TSH. The model of endogenous hormone action reveals that thyroid CCK1 is responsible for the thyroid growth. It can be concluded that the physiological activity of CCK1 receptor plays a significant role in a complex interrelationship between TSH, vagal system and CCK1-dependent function of the thyroid gland.