Thermoadaptive influence on reactivity pattern of vasopressinergic neurons in the guinea pig

In cold-adapted guinea pigs, increased amounts of arginine-vasopressin (AVP) immunoreactive material could be visualized in neurons of the supraoptic and paraventricular nucleus, in fibers projecting to the neurohypophysis and in fiber terminals in the ventral lateral septum and in the amygdala. In warm-adapted animals the reactivity to AVP antiserum was poor in all neuronal structures examined. High AVP-immunoreactivity was accompanied by a reduced febrile response to bacterial pyrogen in cold-adapted guinea pigs.     

Les glycoprotéines sériques dans le granulome expérimental provoqué par la carrageenine

Summary We studied serum glycoproteins in rats and guinea pigs during the development of granulomas, provoked by carrageenin injection. In rats total serum sialic acid was raised as well as sialic acid soluble in sulfosalicylic acid and haptoglobin. The rise of these 2 fractions, seromucoid and haptoglobine accounts quantitatively for the rise of the total sialic acid. In guinea pigs total serum sialic acid was unchanged, but sulfosalicylosoluble sialic acid as well as haptoglobin were much higher than basal values. Quantitatively the serum glycoprotein reaction was much higher in rats than in guinea pigs.     

Einfluss von Isopropyl-isonikotinsäurehydrazid auf den Katecholamingehalt des Myokards

Summary Iproniazid causes a marked prolonged rise in the catecholaminecontent of the heart of guinea pigs. Isoniazid has a much weaker activity in this respect. This effect of iproniazid on the catecholamines of the heart is less marked in other animal species than in guinea pigs.     

Distribution of lysozyme in guinea pigs: implications for the function of gastrointestinal lysozyme in herbivores

High levels of gastrointestinal lysozyme were present in the stomach of guinea pigs, but not in other portions of the gastrointestinal tract. Because the cecum is the fermentation organ of guinea pigs, these observations call into question the validity of the current hypothesis that the gastrointestinal lysozyme of herbivores functions in the digestion of bacteria from the anterior fermentation organ.     

Minoxidil-induced cardiac hypertrophy in guinea pigs

To investigate whether during cardiac hypertrophy changes occur in contractile protein composition and in mechanical and energetic properties of the myocardium, contractile protein composition, isometric force and adenosine triphosphate (ATP) consumption were studied in control and hypertrophied guinea-pig hearts. Cardiac hypertrophy was induced by adding minoxidil (120 or 200 mg/l) to the drinking water. Protein analysis was performed by one-dimensional gel electrophoresis. The myosin heavy-chain (MHC) composition was determined in an enzyme-linked immunosorbent assay (ELISA). ATP consumption and force development were simultaneously measured during isometric contraction in chemically skinned trabeculae. Histochemical analysis of cross-sectional area of cardiomyocytes and interstitial space was performed on the left ventricular tissue of 200 mg/l minoxidil-treated and control guinea pigs. Minoxidil treatment (120 and 200 mg/l) significantly increased left ventricular dry weight normalized for body weight by 19 ± 4 and 24 ± 4%, respectively. No significant differences were found in the cellular cross-sectional area, while interstitial space was slightly decreased in minoxidil-treated hearts. In left ventricular trabeculae of 200 mg/l minoxidil-treated guinea pigs, ATPase activity was slightly less than in those of control guinea pigs, whereas force did not differ significantly. Calcium sensitivity of force and ATPase activity were not affected by minoxidil treatment. Gel electrophoresis revealed no difference in contractile protein composition, but a tendency towards a lower amount of α-MHC in the minoxidil-treated hearts was found in ELISA. Received 1 February 1999; accepted 15 March 1999     

Distribution of lysozyme in guinea pigs: Implications for the function of gastrointestinal lysozyme in herbivores

Summary High levels of gastrointestinal lysozyme were present in the stomach of guinea pigs, but not in other portions of the gastrointestinal tract. Because the cecum is the fermentation organ of guinea pigs, these observations call into question the validity of the current hypothesis that the gastrointestinal lysozyme of herbivores functions in the digestion of bacteria from the anterior fermentation organ.Supported in part by grants RR00515 and RR05465 from the National Institutes of Health.     

Struktur-Wirkungsbeziehungen bei einigen Cardenoliden und Bufadienoliden nach verschiedenartigen Herzschädigungen

Summary By damaging isolated auricles of guinea pigs with 2,4-dinitrophenol, fluoroacetic acid or quinine, it was possible to obtain qualitative differences of effect depending upon the chemical structure of the cardenolids and bufadienolids.     

DNA fragmentation in leukocytes following subacute lowdose nerve agent exposure

The objective of the present study was to determine levels of DNA fragmentation in blood leukocytes from guinea pigs by single-cell gel electrophoresis (comet assay) after exposure to the chemical warfare nerve agent (CWNA), soman, at doses ranging from 0.1 LD₅₀ to 0.4 LD₅₀, once per day for either 5 or 10 days. Post-exposure recovery periods ranged from 0 to 17 days. Leukocytes were imaged from each animal, and the images analyzed by computer. Data obtained for exposure to soman demonstrated significant increases in DNA fragmentation in circulating leukocytes in CWNA-treated guinea pigs compared with saline-injected control animals at all doses and time points examined. Notably, significantly increased DNA fragmentation was observed in leukocytes 17 days after cessation of soman exposure. Our findings demonstrate that leukocyte DNA fragmentation assays may provide a sensitive biomarker for low-dose CWNA exposure.Received 29 July 2003; accepted 14 August 2003     

Conséquences de la thymectomie sur la formule leucocytaire chez le cobaye

Summary In infantile guinea pigs, thymectomy determined a decrease of the leucocyte count in the circulating blood, resulting essentially from the decreased number of lymphocytes.Eosinophiles increased noticeably in the same animals.Thus the consequences of thymectomy were proved to be exactly opposite to those of administration of thymus extract as described in a previous publication.     

Quantitative differences in the pharmacological effects of (+)- and (-)-cathinone

The optically pure isomers of cathinone were prepared by separating synthetic cathinone racemate and used to study central and peripheral effects of these indirect sympathomimetics in rats and guinea pigs. The (-)-isomer was significantly more potent than the (+)-isomer in stimulating locomotor activity whereas no difference was observed with respect to their cardiac effects. In analogy to observations with (+)- and (-)-amphetamine such variable isomer discrimination may be due to different stereoselectivities of amine uptake mechanisms in the target tissues.     

Zur Abhängigkeit der Aktivierungsenergie der Gewebsatmung bei Säugetieren von der Körpergrösse

Summary (1) The activation energy of the liver respiration in an interval of temperature between 17.5 and 37.5°C was determined in mice, rats, and guinea pigs. (2) A systematic decrease with increasing body size was observed.     

Quantitative differences in the pharmacological effects of (+)- and (−)-cathinone

Summary The optically pure isomers of cathinone were prepared by separating synthetic cathinone racemate and used to study central and peripheral effects of these indirect sympathomimetics in rats and guinea pigs. The (–)-isomer was significantly more potent than the (+)-isomer in stimulating locomotor activity whereas no difference was observed with respect to their cardiac effects. In analogy to observations with (+)- and (–)-amphetamine such variable isomer discrimination may be due to different stereoselectivities of amine uptake mechanisms in the target tissues.     

Study of prostaglandin synthesis during anaphylactic shock in guinea pigs]

In guinea pigs actively sensitized with ovalbumin and shocked, we have measured blood histamine and histaminase, pulmonary content in cycli AMP and prostaglandins (PG) E1, E2 and F2alpha. In pulmonary efferent blood, both PGE and PGF are increased. In lung tissue, only PGF2alpha, which are bronchoconstructive mediators, are increased. Th increased level in PG seems to have two origins: first a specific increase, then an increased synthesis secondary to histamine release.     

聚焦超声辐照豚鼠慢性湿疹模型的超微结构变化

目的探讨聚焦超声辐照豚鼠慢性湿疹模型豚鼠的皮肤超微结构改变。方法豚鼠32只，以2，4-二硝基氯苯（DNCB）为抗原，小剂量多次刺激豚鼠背部皮肤制备慢性湿疹模型。随机分为辐照组3组和对照组，辐照组以频率10MHz、声功率3W的连续波直接辐照模型皮肤真皮层，3组分别于辐照后1、7和14天取材，对照组不辐照立即取材，做透射电镜观察．结果辐照前可见表皮角质层增厚明显，成纤维细胞线粒体肿胀、粗面内质网扩张，细胞间隙加大；辐照后第1天和7天可见血管内皮细胞线粒体肿胀、微吞饮小泡数量多，成纤维细胞线粒体肿胀、粗面内质网扩张，但细胞间隙变小；第14天基本恢复正常。结论聚焦超声可用于治疗湿疹，有利于微血管和胶原纤维的增生与修复，可使患处上皮细胞及真皮组织的超微结构趋于恢复正常。     

Der Einbau von radioaktiv markiertem Schwefel (35S) in den Knorpel normaler und Vitamin-C-frei ernährter Meerschweinchen

Summary The utilization of sulphate labelled with S³⁵ to the synthesis of chondroitin sulphate of the cartilage of normal and scorbutic guinea pigs has been examined. The average incorporation of S³⁵ in the costal cartilage in the deficient animal was about one half that of the normal.     

Changes in body temperature and circulating levels of interleukin-6 after intra-arterial injections or infusions of tumor necrosis factor α in guinea pigs

Tumor necrosis factor (TNF) is released systematically during the early phase of endotoxin induced fever. To study the effects of this cytokine in guinea pigs, 2 g TNF were intra-arterially injected as a bolus or slowly infused within 60 min. Both modes of administration induced a biphasic elevation of the animals' abdominal temperature lasting 6 h and stimulated the release of endogenous interleukin-6 (IL-6)-like activity. The second phase of the thermal response and the release of endogenous IL-6-like activity were significantly higher, when TNF was slowly infused into the animals' circulation, in spite of a transiently higher TNF-like activity after the bolus injection of TNF. Both TNF and IL-6 may therefore be regarded as candidates to trigger the febrile response in guinea pigs.     

Stimulierung der Atmung durch Bradykinin und Kallidin

Summary In guinea pigs and rabbits small doses of bradykinin and kallidin (1–8 µg/kg i.v.), which have no bronchoconstrictor effect, stimulate respiration causing tachy- and hyperpnea. Bilateral vagotomy as well as salicylates (4–40 mg/kg i.v.) abolish these respiratory responses.     

Réactions cytologiques à l'introduction pulmonaire expérimentale de particules de silicium métalloïdique

Summary By means of intratracheal injection, particles of metalloid silicium about five microns in size are introduced into the lungs of guinea pigs, and the secondary parenchymatous reactions are studied from 10 minutes to 105 days. In the dust cells, the silicium is progressively broken up into very small particles of less than 1 micron in size. The cells do not show degeneration or mummification as the ordinary silica cells (Mavrogordato) do.     

Low-molecular-weight enzyme inhibitors suppress the development of experimental allergic encephalomyelitis

We tested the activity of low-molecular-weight enzyme inhibitors with immunomodifying actions on the suppression of experimental allergic encephalomyelitis (EAE). Of the agents tested the inhibitors of alkaline phosphatase, aminopeptidase B and esterase gave significant protection against the clinical expression of EAE in guinea pigs.     

Low-molecular-weight enzyme inhibitors suppress the development of experimental allergic encephalomyelitis

Summary We tested the activity of low-molecular-weight enzyme inhibitors with immunomodifying actions on the suppression of experimental allergic encephalomyelitis (EAE). Of the agents tested the inhibitors of alkaline phosphatase, aminopeptidase B and esterase gave significant protection againts the clinical expression of EAE in guinea pigs.Acknowledgments. This work was partly supported by a grant-in-aid for New Drug Development Research from the Ministry of Health and Welfare, Japan.