Ultrastructural Changes in Calvarial Osteoblast Cytoskeleton after Prostaglandin E2 Administration in Rats

Recent studies on the cytoskeleton of osteoblasts have been made mainly using cultured cells. However, the morphology of cultured cells may be altered during subculture. Therefore, cytoskeletal changes of calvarial osteoblasts were investigated in situ by electron microscopy using the detergent perfusion method to preserve cell morphology as well as selectively observing the cytoskeleton in the presence of a high concentration of prostaglandin E2 (PGE2) in the calvarial periphery in rats. Rats were perfused with a mixture of Triton X-100 and glutaraldehyde, then the cytoskeleton was observed by transmission electron microscopy. In osteoblasts of the control group, thick bundles of microfilaments ran parallel to the long axis of the cells immediately below the cell membrane adjacent to the osteoid layer. In contrast, in the osteoblasts of the PGE2-administered group, the external morphology was changed to an asteroid or cubic shape, and thick bundles of microfilaments immediately below the cell membrane adjacent to the osteoid were not observed, although microfilament fibres, with a diameter of 5-6 nm, were observed in the cytoplasm.     

Cervixerweiterung und Lutealfunktion nach intracervicaler Injektion eines synthetischen Prostaglandin E2 -Derivats beim Rind

Inhalt Die intracervicale Injektion eines synthetischen Prostaglandin E₂-Derivats führte beim Rind zu einer Erleichterung der Cervixpassage, ohne die Lutealfunktion zu beeinträchtigen. Die Anwendbarkeit der Methode im Rahmen des unblutigen Embryotransfers wird diskutiert. Contents Cervical dilatation and luteal function in cattle after intracervical injection of a synthetic prostaglandin E₂ -derivate. Intracervical injection of a synthetic prostaglandin E₂ -derivative resulted in cervical softening thus facilitating passage through the cervix in cattle. Luteal function was not affected by the treatment. The implication of the method in connection with nonsurgical embryo transfer is discussed.     

Assessment of histamine, bradykinin, prostaglandins E1 and E2 and carrageenin as vascular permeability agents in the horse

The vascular leakage induced by histamine, bradykinin, serotonin and prostaglandin E1 and E2 was assessed. The test agents were injected intradermally into the shaved thoracic skin of horses and the vascular leakage estimated either semi-quantitatively by recording the diameter of the lesions or by measuring the actual volume of extravasated plasma in microliters using iodine-125-labelled human serum albumin (125I-HSA) as a marker in the blood plasma. Using the latter method, the vascular leakage induced by carrageenin and the effect of coadministered prostaglandins E1 and E2 upon the vascular leakage of both histamine and bradykinin were also investigated. No obvious lesions resulted when serotonin (10(-2) mol/l) was injected but histamine and bradykinin produced circular lesions which increased in diameter for approximately 30 min. The size of the lesions and volume of extravasated plasma was dose dependent. On a molar basis, bradykinin (10(-6) mol/l, 10(-5) mol/l) was more potent than histamine but they were equipotent at 10(-4) mol/l. The size of the lesions induced by carrageenin were independent of their anatomical location on the thorax. Except for the second hour, the hourly volume of vascular leakage increased until the fifth hour when the experiment was concluded. The maximum vascular leakage resulting from the injection of prostaglandin E1 or E2 (1, 10, 100 or 1000 ng) was 7 microliters but when co-administered with bradykinin (10(-6) mol/l), the volume of leaked plasma increased from 29 to 78 microliters. No synergy was observed when either prostaglandin was co-administered with histamine (10(-5) mol/l).     

Vascular leakage induced by histamine, bradykinin, serotonin and prostaglandin E2 in Greyhounds

SUMMARY Vascular leakage induced by intradermal injection of histamine, bradykinin and serotonin alone and co-injected with prostaglandin E₂ was measured in Greyhounds using ¹²⁵Iodine-labelled human serum albumin (¹²⁵I-HSA) as a marker in the blood. Histamine and bradykinin produced dose-dependent vascular leakage. At equimolar concentrations, histamine was more than twice as potent as bradykinin. Serotonin did not induce vascular leakage and was irritant. Prostaglandin E₂ did not induce significant vascular leakage (maximum 5μL) when injected alone, but when co-injected with histamine and bradykinin, the vascular leakage of both histamine and bradykinin was increased. This effect was more pronounced if lower concentrations of histamine and bradykinin were injected. The induced vascular leakage was greatest during the first five minutes of lesion development for histamine, during the second five minutes of lesion development for bradykinin, and the synergistic effect of prostaglandin E₂ was maximal during the third five minute period of lesion development.     

Role of Tumour Necrosis Factor α in Stimulation of Prostaglandins F2α and E2 Release by Cultured Porcine Endometrial Cells

The present studies were undertaken to examine the effect of tumour necrosis factor (TNF) alpha on prostaglandins (PGs) F(2alpha) and E(2) release by cultured porcine endometrial cells harvested on days 13-16 after oestrus in comparison to stimulation with oxytocin (OT) and luteinizing hormone (LH). A time-dependent effect of TNFalpha (10 ng/ml) on PGF(2alpha) release was observed in stromal and luminal epithelial cells. Moreover, TNFalpha increased PGF(2alpha) secretion from both endometrial cell types with effective concentrations of 1 (p < 0.05), 10 and 50 ng/ml (p < 0.01). The effect of TNFalpha (10 ng/ml) on endometrial PGF(2alpha) and PGE(2) release was compared with OT (100 nmol/l) and LH (100 ng/ml). All factors affected PGF(2alpha) secretion from stromal cells, however, the stimulation tended to be more potent after OT and LH (p < 0.01) than after TNFalpha (p < 0.05) treatment. In epithelial cells, only TNFalpha was able to stimulate PGF(2alpha) release (p < 0.001). PGE(2) secretion from stromal cells increased after incubation with TNFalpha and OT (p < 0.05). Only LH stimulated PGE(2) release from epithelium (p < 0.001), and its action was very effective when compared with TNFalpha or OT (p < 0.01). Summarizing, TNFalpha induces both PGs secretion from cultured porcine endometrium, but preferentially stimulates PGF(2alpha) release from luminal epithelial cells. Therefore, similarly to OT and LH, TNFalpha may be considered as a potential modulator of endometrial PGF(2alpha) production during luteolysis in the pig.     

Kontrolle der luteolytischen Wirkung eines neuen Prostaglandin F2α-Analogs bei der Behandlung von Stuten mit Anostrie and Dyszyklie unter fortlaufender Bestimmung des Progesteronspiegels im Plasma

Inhalt 15 Stuten mit Anöstrie bzw. Dyszyklie wurden unter Kontrolle ihres Plasmaprogesteronspiegels mit einem Prostaglandinanalog (Hoe 837 V; 0,1 mg/ml) behandelt. Die Progesteronwerte lagen vor der Behandlung zwischen 1,6 ng/ml and 13,6 ng/ml. Eine ausreichende Luteolyse lieβ sich bei 14 Stu ten mit einer einzigen intramuskulären Injektion von 3,3 ml induzieren. Die Marke von 1 ng/ml war bei 9 Stuten schon am ersten and bei weiteren 5 Stuten am zweiten Tag nach der PG-Injektion erreicht. Die während der Rosse gemessenen Progesteronwerte entsprachen weitgehend den von anderen Autoren bestimmten. Dauer and Verlauf der Rosse waren wie bei nicht behandelten Stuten. 2–7 Tage nach Rossebeginn bzw. zwischen dem 5. and 12. Tag nach der PG-Behandlung stiegen die Progesteronwerte wieder über 1 ng/ml. In der Lutealphase erreichten sie bei den tragend gewordenen Stuten schnell einen Spitzenwert um 8 ng/ml (x?). Die Verlaufskurven zeigten groβe individuelle Unterschiede hinsichtlich des Progesteronniveaus. Bei Stuten mit späterer Fruchtresorption wurde zwischen dem 5./6. bis 13./14. Tag ein deutliches Progesterondefizit erkennbar. Von 2 Stuten, die in der induzierten Rosse nicht konzipierten, hatte die eine einen verkürzten, die andere einen spontan verlängerten Diöstrus. Die Frühkonzeptionsrate betrug 84,6 %. Nachkontrollen ergaben, daβ 61,5 % der behandelten Stuten tragend wurden. Pro Trächtigkeit waren durchschnittlich 1,6 Sprünge erforderlich. Contents Control of the luteolytic effect of a new prostaglandin F₂α-analogue during the treatment of anestrous and dyscyclic mares under continual measurement of the progesterone level in the blood plasma. 15 mares in clinical anestrus and dyscyclia were treated with the prostaglandin F₂α-analogue (Hoe 837 V; 0,1 mg/ml) under control of the plasma progesterone level. Before treatment the plasma progesterone values ranged between 1.6 ng/ml and 13.6 ng/ml. A satisfactory luteoly tic response was obtained with a single intramusculary dose of 3.3 ml in 14 mares. 24–48 h after the PG-injection progesterone declined to baseline levels of 1 ng/ml. The mares came to estrus 1–2 days after falling of progesterone < 1 ng/ml or 1–6 days after the PG-injection. Progesterone values measured in the estrus-period were like those determined from other authors. Duration and performance of estrus were as in untreated mares. 2–7 days from the onset of estrus and between five to twelve days after treatment, the progesterone levels again arose >1 ng/ml. In the lutealphase in pregnant mares they reached a peak of 8 ng/ml (x?) quickly. The progesterone courses showed great individual difference in their basal levels. In mares undergoing embryonic resorption a progesterone deficiency is seen in the early lutealphase between the 5.16. day and 13.114. day. From the two mares which did not conceive in the induced estrus one had a shortened and another a prolonged diestrus. The conception rate for early pregnancy was 84.6 %, and still 61.5 % for late pregnancy. In the average for each pregnancy 1.6 copulations were needed.     

Utilization of F1 information in estimating QTL effects in F2 crosses between outbred lines

Quantitative trait loci (QTL) analysis in designed experiments is investigated using a mixed model framework through the modification of segment mapping techniques. Allele effects are modelled in the F₁ generation allowing the estimation of additive substitution effects while accounting for QTL segregation within lines and differences in mean QTL effects between lines. The resulting approach is called F₁ segment mapping. Simulation is used to illustrate the method and its properties. F₁ segment mapping has advantages over F₂ segment mapping in the derivation of exact additive genetic covariances and in the computation time for variance component estimation.     

Einsatz von 3H-Aktynomyzin/3H-AMD/ in den mikroautoradiographischen Untersuchungen der Alterungsprozesse eines langfristig in flüssigem Stickstoff aufbewahrten Bullenspermas

Mit dem mikroautoradiographischen Verfahren unter Einsatz von ^/3 H-Aktynomyzin/ ³ H-AMD/ wurde bereits im Verlauf des Einfriervorganges eine Störung des Gleichgewichtszustandes im Bereich der DNP-Komplexe des Spermienkopfes ermittelt. Diese Erscheinung zeigt sich in einer ansteigenden Anzahl von Einschlussen von ³ H-AMD. Es wurde eine Abhängigkeit dieses Proresses aber nicht nur von den Einfrierphasen, sondern auch vom Alter der Bullen und der Zeitdauer der Konservierung des Spermas nachgewiesen. Die niedrigsten Werte der Einschlüsse von ³ H-AMD wurden bei einer Aufbewahrungsdauer der Spermienproben von 3 Monaten bis 5 Jahre ermittelt. Die aus den 6–9 Jahre aufbewahrten Samenproben gewonnenen Spermien waren durch einen hohen Markierungsgrad charakterisiert, was auf Störungen der elektrostatischen Einwirkungen zwischen DNP und Kernproteinen dieser Samenzellen hindeutet .     

Untersuchungen über Rassenunterschiede in der Milchleistung beim Schwein I. Mitteilung: Methodik des maschinellen Milchentzuges und Milchmengenleistung

Inhalt: Die vorliegende Untersuchung stellt einen Beitrag zur Methodik des maschinellen Milchentzuges beim Schwein dar. Mittels einer eigens hierzu entwickelten Melkmaschine wurde die Milchleistung der in ihren Muttereigenschaften stark differierenden Rassen Pietráin (PI) und Deutsches Edelschwein (DE) ermittelt. Der Milchentzug erfolgte in 2-stündigen Kontrollabschnitten an den Laktationstagen 3, 7,14, 21 und 28. Bei DE kam es während der 4wöchigen Laktationsphase zu einer gleichmäβigen Steigerung der Milch-sekretion von 5,05 1 am 3. Tag auf 12,8 l am Tag 28. Die Sekretionsrate der Rasse PI folgte diesem Verlauf, quantitativ um 2 bis 3 l/d reduziert, bis zu einem Maximum am 14. Laktationstag. Danach sank sie wieder ab. Am Tag 28 betrug der Leistungsunterschied zwischen beiden Rassen über 5 l/Tag. Mit dieser überlegenen Milchsekretionsrate zogen die DE-Sauen 3 Ferkel/Wurf mehr aufals die PI. Auch nach der Standardisierung derFerkelzahl zu Untersuchungsbeginn auf n = 10 blieb die Direrenz zugunsten der Edelschweine signifikant erhalten. Über die Milchinhaltsstoffe und ihre Abhängigkeit von Rasse und Laktationstag sowie ihre Bedeutung für die Lebendmasseentwicklung der Ferkel wird in der II. Mitteilung berichtet. Contents: Investigations on breed differences in milk yield of swine. I. comittment: methodology of mechanical milking and milk yield. This paper deals with the methodology of mechanical milking of sows. By a milking machine, especially developed herefore, milk yields of the breeds Pietrain (PI) and German Large White (DE) which differ a lot in weaning performance, were investigated. Milk was taken in two-hourly control intervalls on the days 3,7,14,21 and 28 of lactation. During this period of 4 weeks, DE showed a continuous increase in milk yield from 5.05 l on day 3 to 12.8 l on day 28. Secretion rate of PI followed parallel with a quantitative decrease of 2 to 3 liters/day, till a maximum was reached on day 14. Then lactation rates decreased. The difference in yield performance between the two breeds was about 5 l on day 28. This superior milk performance of the DE-sows allowed them to wean 3 piglets per litter more than PI. The advantage of DE over PI stays even after standardization of the litter size on n = 10 piglets. Milk composition, its relation towards breed and lactation day and its meaning for the litter performance will be topic of the second comittment.     

Comparative study of the action of flunixin meglumine and tolfenamic acid on prostaglandin E2 synthesis in bovine inflammatory exudate

An acute non-immune inflammation model was used to compare the action of two non-steroidal anti-inflammatory drugs, flunixin meglumine and tolfenamic acid, on prostaglandin E₂, (PGE₂) synthesis in bovine inflammatory exudate. The tissue cage model used involves subcutaneous implantation of polypropylene cages and subsequent stimulation by carrageenan injection of the granulation tissue which develops within the cage. Twelve calves were randomly assigned to three groups receiving placebo, flunixin meglumine and tolfenamic acid, respectively. Inflammatory exudate was sampled 30 min after carrageenan injection and at seven subsequent time points. PGE², levels were determined by radioimmunoassay. At each time point post-carrageenan injection, flunixin meglumine inhibited PGE₂, synthesis to a greater extent than tolfenamic acid. At 4, 8,12 and 24 h these differences were statistically significant.     

Alpha-adrenoceptors in equine digital veins: Evidence for the presence of both alpha1 and alpha2-receptors mediating vasoconstriction

Rings of equine digital vein examined under conditions of isometric tension recording constricted to alpha-adrenoceptor agonists with an order of potency of 5-bromo-6-[2-imidazolin-2-yl-amino]-quinoxaline bitartrate (UK 14304) = noradrenaline > 6-Allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo-(4,5-d) azepine (BHT-920) > phenylephrine > dopamine > methoxamine. The maximum force generated was greatest for the non-selective agonist noradrenaline and lowest for the alpha₂-selective agonist BHT-920 with the other agonists between these two extremes. Selective inactivation of alpha₁-adrenoceptors (achieved by treating yohimbine-protected tissues with phenoxybenzamine) reduced the maximum responses of all agonists, the EC₅₀ values of UK 14304, BHT-920 and noradrenaline and increased the EC₅₀ values of phenylephrine and methoxamine. Prazosin (30 n M ) had no inhibitory effect on responses to low concentrations of BHT-920 and UK 14304 and caused competitive inhibition of responses to phenylephrine and noradrenaline giving pK_b values of 8.49 ± 0.18 and 8.23 ± 0.14, respectively. Yohimbine (0.1 μ M ) caused significant competitive inhibition of responses to BHT-920 and noradrenaline with calculated pK_b values of 8.43 ± 0.11 for BHT-920 and 7.43 ± 0.31 for noradrenaline and non-competitive inhibition of responses to UK 14304. 2-[2-methoxy-1,4-benzodioxan-2-yl]-2-imidazoline (RX 821002; 10 n M ) caused competitive inhibition of responses to BHT-920 (pK_b 9.04 ± 0.27) and dopamine (pK_b 8.2 ± 0.2). These data indicate that equine digital veins possess both post-synaptic alpha₁ and alpha₂-adrenoceptors.     

Morphologie und Entwicklung der A. ovzrica. beim Rind in der Fetal- und Neonatalperiode2

Morphology and development of the bovine ovarian artery during the fetal and postnatal periods
Development and morphology of the ovarian artery was studied in 106, 9–40 week-old fetuses and 14, 2–14 day-old calves. Different factors were considered such as time-dependent position and mode of branching from the aorta, the course of the ovarian artery in relation to the ovarian vein, and the artery's secondary distribution. Marked developmental changes which in time disappeared, become more prominent, or were reduced, could be demonstrated.