Perfusion of the Boar Testis with Androstenediol Sulfate in vivo and Studies on the in vitro Metabolism of Androgens by Porcine Blood Cells

1973 ◽  
Vol 51 (4) ◽  
pp. 390-396 ◽  
Author(s):  
M. A. Kraemer ◽  
J. I. Raeside
Keyword(s):  
Blood Cells ◽  
Dehydroepiandrosterone Sulfate ◽  
Spermatic Vein ◽  
In Vivo Studies ◽  
Similar Amount ◽  
Secretory Product ◽  
Arterial Blood ◽  
Almost All

An attempt was made to see if androstenediol sulfate, a normal secretory product of the boar testis, is important in testicular steroidogenesis in this species when perfused in vivo through the testis. Approximately 5 μCi of 7α-3H-androstenediol sulfate were administered via the spermatic artery to four, mature, anesthetized boars. Almost all of the radioactivity extracted from the spermatic vein blood and from the testis was associated with the unaltered substrate. Less than 0.2% of the substrate was isolated as 3H-dehydroepiandrosterone sulfate from the testicular extracts of one boar. An unsuccessful effort was made to characterize a similar amount of a metabolite present in extracts from spermatic vein blood of the same animal. The total amount of radioactivity which was associated with the free steroids represented about 0.2% of the administered dose of 3H-androstenediol sulfate given to each boar.17β-Hydroxysteroid dehydrogenase activity was demonstrated in a series of incubations of steroids with blood cells of the boar. Unconjugated Δ5-steroids were converted to a greater extent than were the Δ4-steroids (3.33 and 3.91% for DHA and androstenediol, respectively; 1.23 and 0.92% for androstenedione and testosterone, respectively). Androstenediol sulfate was converted to dehydroepiandrosterone sulfate (0.42%) but the reverse reaction was not observed. These findings were considered in relation to the in vivo studies. It was concluded that androstenediol sulfate in arterial blood entering the boar testis was not metabolized appreciably.

Mg2+–Ca2+ interaction in contractility of vascular smooth muscle: Mg2+ versus organic calcium channel blockers on myogenic tone and agonist-induced responsiveness of blood vessels

1987 ◽  
Vol 65 (4) ◽  
pp. 729-745 ◽  
Author(s):  
B. M. Altura ◽  
B. T. Altura ◽  
A. Carella ◽  
A. Gebrewold ◽  
T. Murakawa ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Vascular Smooth Muscle ◽  
Blood Vessels ◽  
Divalent Cations ◽  
Smooth Muscles ◽  
In Vivo Studies ◽  
Channel Blockers ◽  
Arterial Blood

Contractility of all types of invertebrate and vertebrate muscle is dependent upon the actions and interactions of two divalent cations, viz., calcium (Ca2+) and magnesium (Mg2+) ions. The data presented and reviewed herein contrast the actions of several organic Ca2+ channel blockers with the natural, physiologic (inorganic) Ca2+ antagonist, Mg2+, on microvascular and macrovascular smooth muscles. Both direct in vivo studies on microscopic arteriolar and venular smooth muscles and in vitro studies on different types of blood vessels are presented. It is clear from the studies done so far that of all Ca2+ antagonists examined, only Mg2+ has the capability to inhibit myogenic, basal, and hormonal-induced vascular tone in all types of vascular smooth muscle. Data obtained with verapamil, nimopidine, nitrendipine, and nisoldipine on the microvasculature are suggestive of the probability that a heterogeneity of Ca2+ channels, and of Ca2+ binding sites, exists in different microvascular smooth muscles; although some appear to be voltage operated and others, receptor operated, they are probably heterogeneous in composition from one vascular region to another. Mg2+ appears to act on voltage-, receptor-, and leak-operated membrane channels in vascular smooth muscle. The organic Ca2+ channel blockers do not have this uniform capability; they demonstrate a selectivity when compared with Mg2+. Mg2+ appears to be a special kind of Ca2+ channel antagonist in vascular smooth muscle. At vascular membranes it can (i) block Ca2+ entry and exit, (ii) lower peripheral and cerebral vascular resistance, (iii) relieve cerebral, coronary, and peripheral vasospasm, and (iv) lower arterial blood pressure. At micromolar concentrations (i.e., 10–100 μM), Mg2+ can cause significant vasodilatation of intact arterioles and venules in all regional vasculatures so far examined. Although Mg2+ is three to five orders of magnitude less potent than the organic Ca2+ channel blockers, it possesses unique and potentially useful Ca2+ antagonistic properties.

Exogenous NO inhibits basal NO release from vascular endothelium in vitro and in vivo

1996 ◽  
Vol 271 (5) ◽  
pp. H2045-H2051 ◽  
Author(s):  
X. L. Ma ◽  
B. L. Lopez ◽  
T. A. Christopher ◽  
D. S. Birenbaum ◽  
J. Vinten-Johansen
Keyword(s):  
In Vivo Studies ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
No Donor ◽  
Parent Molecule ◽  
Arterial Blood ◽  
No Release ◽  
Basal Release

This study tested the hypothesis that exogenous nitric oxide (NO) inhibits basal release of NO in isolated rat aortic rings and in vivo. Thoracic aortic rings were suspended in organ chambers with Krebs-Henseleit solution. In untreated rings, the NO synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME) markedly increased basal vascular tone by 34.6 +/- 5.2% of maximal force produced by 100 nM thromboxane A2 mimetic U-46619, indicating a basal release of NO. Other rings were pretreated with the exogenous NO donor S-nitroso-N-acetylpenicillamine (SNAP) for 20 min and then washed free of drug. In these rings, L-NAME-induced vasoconstriction was significantly attenuated in a concentration-dependent manner (from 34.6 +/- 5.2 to 25.7 +/- 2.9% at SNAP = 0.5 microM, 15.2 +/- 3.1% at 1 microM, and 11.9 +/- 2.5% at 5 microM), while having no effect on NO-independent phenylephrine-induced vasoconstriction (35.4 +/- 4.7 untreated vs. 41.3 +/- 4.3% SNAP pretreated, not significant). In addition, the nonnitrosylated parent molecule of SNAP, acetylpenicillamine, had no effect on the vasoconstriction induced by L-NAME. In the in vivo studies in anesthetized rats, L-NAME caused significant hypertensive responses (34 +/- 4-mmHg increase in mean arterial blood pressure). Subvasoactive doses of SNAP attenuated these hypertensive responses in a dose-dependent manner (20 +/- 3-mmHg increase with 10 micrograms/kg SNAP pretreatment and 16 +/- 4-mmHg increase with 20 micrograms/kg SNAP pretreatment), but any dose of acetylpenicillamine studied had no effect. Coadministration of superoxide dismutase and SNAP significantly potentiated the inhibitory effect of the NO donor on vasocontraction responses to L-NAME. Furthermore, SNAP did not attenuate the hypertensive responses to phenylephrine. These results indicate that exogenous NO significantly inhibits basal NO release both in vitro and in vivo, suggesting that NO plays an important negative-feedback regulatory role under physiological conditions.

scholarly journals Studies on Agranulocytosis. II. The Effect of Chlorpromazine upon the Influx of S35 L-Cystine and L-Methionine into Human Leukocytes

Blood ◽  
1960 ◽  
Vol 16 (4) ◽  
pp. 1456-1468 ◽  
Author(s):  
ANTHONY V. PISCIOTTA ◽  
SHIRLEY N. EBBE ◽  
MARY DALY ◽  
MONA RUWALDT ◽  
MILTON GLASER ◽  
...  
Keyword(s):  
Whole Blood ◽  
Blood Cells ◽  
The Other ◽  
In Vivo Studies ◽  
Human Leukocytes ◽  
In Vivo Administration

Abstract 1. When whole blood was incubated in vitro with S-35 L-cystine and L-methionine, the blood cells became radioactive. 2. Preincubation of whole blood from normals and from patients susceptible to agranulocytosis with chlorpromazine showed no effect upon uptake of S-35 L-cystine and L-methionine by leukocytes. 3. The in vivo administration of S-35 L-cystine was followed by the appearance of radioactive leukocytes. Peak radioactivity occurred in leukocytes in 5 to 12 days. 4. Pretreatment of test subjects with large doses of chlorpromazine did not block the uptake of S-35 L-cystine by leukocytes in vivo. Leukocytes of women showed an increase in the incorporation of S-35 L-cystine, in vivo. Studies performed in vivo on two persons during recovery from agranulocytosis showed enhanced uptake of L-cystine in one and a normal uptake in the other.

Glomerular prostaglandin formation in two-kidney, one-clip hypertensive rats

1984 ◽  
Vol 247 (6) ◽  
pp. F975-F981 ◽  
Author(s):  
R. A. Stahl ◽  
U. Helmchen ◽  
M. Paravicini ◽  
L. J. Ritter ◽  
P. Schollmeyer
Keyword(s):  
Blood Pressure ◽  
Filtration Rate ◽  
In Vivo Studies ◽  
Cyclooxygenase Inhibitor ◽  
Severe Damage ◽  
Hypertensive Rats ◽  
Cyclooxygenase Inhibition ◽  
Arterial Blood

In vitro prostaglandin (PG) and thromboxane B2 (TXB2) formation by isolated glomeruli from normotensive (N) and two-kidney, one-clip hypertensive (2K,1C) rats was determined. When calculated on the basis of glomerular protein content, PGE2, 6-keto-PGF1 alpha and TXB2 production of glomeruli from clipped kidneys was significantly greater than PG and TXB2 formation of glomeruli from the untouched kidneys. When PG and TXB2 formation was calculated per amount of glomeruli, only PGE2 formation was found to be significantly greater in clipped kidneys. No severe damage of glomerular structure was found in the kidneys when studied by light microscopy. In additional in vivo studies, the effect of the cyclooxygenase inhibitor indomethacin on blood pressure and glomerular filtration rate (GFR) was evaluated. Following indomethacin GFR in 7 of 13 clipped kidneys of 2K,1C rats decreased from 363 +/- 77 to 188 +/- 51 microliter/100 g body wt, whereas six kidneys developed anuria. No effect of cyclooxygenase inhibition on GFR was found in N rats and in untouched kidneys of 2K,1C rats. Mean arterial blood pressure in 2K,1C hypertension fell significantly, from 158 +/- 10 to 135 +/- 7 mmHg, after cyclooxygenase inhibition. No effect was seen in N rats. The data suggest that increased glomerular PG formation in the clipped kidneys of 2K,1C rats is involved in the pathogenesis of hypertension in this animal model.

scholarly journals In vivo Muscarinic Cholingeric Receptor Imaging in Human Brain with [11C]Scopolamine and Positron Emission Tomography

1992 ◽  
Vol 12 (1) ◽  
pp. 147-154 ◽  
Author(s):  
K. A. Frey ◽  
R. A. Koeppe ◽  
G. K. Mulholland ◽  
D. Jewett ◽  
R. Hichwa ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Kinetic Analysis ◽  
Muscarinic Receptor ◽  
Emission Tomography ◽  
In Vivo Studies ◽  
Receptor Imaging ◽  
Arterial Blood ◽  
Positron Emission

Cerebral muscarinic cholinergic receptors were imaged and regionally quantified in vivo in humans with the use of [11C]scopolamine and positron emission tomography. Previous studies in experimental animals have suggested the utility of radiolabeled scopolamine for in vivo measurements, on the bases of its maintained pharmacologic specificity following systemic administration and the exclusion of labeled metabolites from the brain. The present studies describe the cerebral distribution kinetics of [11C]scopolamine in normal subjects following intravenous injection. Scopolamine is initially delivered to brain in a perfusion-directed pattern. After 30 to 60 min, activity is lost preferentially from cerebral structures with low muscarinic receptor density including the cerebellum and thalamus. Activity continues to accumulate throughout a 2 h postinjection period in receptor-rich areas including cerebral cortex and the basal ganglia. The late regional concentration of [11C]scopolamine does not, however, accurately parallel known differences in muscarinic receptor numbers in these receptor-rich areas. Tracer kinetic analysis of the data, performed on the basis of a three-compartment model, provides receptor binding estimates in good agreement with prior in vitro measurements. Kinetic analysis confirms significant contributions of ligand delivery and extraction to the late distribution of [11C]scopolamine, reconciling the discrepancy between receptor levels and tracer concentration. Finally, a novel dual-isotope method for rapid chromatographic processing of arterial blood samples in radiotracer studies is presented. The combination of rapid chromatography and compartmental analysis of tracer distribution should have broad utility in future in vivo studies with short-lived radioligands.

scholarly journals Natural Treatments for Fissure in Ano Used by Traditional Persian Scholars, Razi (Rhazes) and Ibn Sina (Avicenna)

2016 ◽  
Vol 22 (2) ◽  
pp. 324-333 ◽  
Author(s):  
Ali Reza Derakhshan
Keyword(s):  
Anal Fissure ◽  
Scientific Evidence ◽  
Modern Medicine ◽  
In Vivo Studies ◽  
Lifestyle Modifications ◽  
Fissure In Ano ◽  
Ibn Sina ◽  
Almost All

Most cases of chronic fissure do not respond to medical treatment. Razi and Ibn Sina were 2 of the best-known scientists of ancient Persia. The purpose of this study was to find out new scientific evidence in modern medicine about their recommendations, in order to find certain clues to conduct useful researches in the future. First, treatments of anal fissure mentioned by Razi and Ibn Sina were reviewed. Then, literature search was made in electronic databases including PubMed, Scopus, and Google Scholar. Management of anal fissure according to Razi’s and Ibn Sina’s practices is done based on 3 interventions: lifestyle modifications, drug treatments, and manual procedures. Almost all remedies suggested by Razi and Ibn Sina have shown their effects on fissure in ano via several mechanisms of action in many in vitro and in vivo studies; Still there is lack of human studies on the subject.

scholarly journals COVID-19 TEDAVİSİNE YÖNELİK GÜNCEL FARMAKOLOJİK YAKLAŞIMLAR

2021 ◽  
Author(s):  
Ezgi Eroğlu ◽  
Hakan Balcı ◽  
Veysel Baskın ◽  
Zuhal Aktuna
Keyword(s):  
Specific Treatment ◽  
In Vivo Studies ◽  
Wholesale Market ◽  
Randomized Controlled ◽  
Therapeutic Drugs ◽  
The World ◽  
Current Outbreak ◽  
Almost All

The current outbreak of coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) occurred in the wholesale market in Wuhan, China in the last months of 2019 and spread to almost all countries in the world. Although there is currently no specific treatment for COVID-19, certain agents are used worldwide, based on in vitro, in vivo studies, and randomized controlled trials. In this review, brief information about these drugs used for the treatment of COVID-19, the results of the conducted studies and the possible adverse effects of the drugs are summarized. We hope that this review will provide an impression of the most current therapeutic drugs used to prevent, control and treat COVID-19 patients until the approval of vaccines and specific drugs targeting SARS-CoV-2. Key Words: COVID-19, SARS CoV-2, pharmacotherapeutics

scholarly journals Haematological and morphological evaluation of feline whole blood units collected for transfusion purposes

2018 ◽  
Vol 21 (8) ◽  
pp. 732-740 ◽  
Author(s):  
Eva Spada ◽  
Roberta Perego ◽  
Luciana Baggiani ◽  
Daniela Proverbio
Keyword(s):  
Whole Blood ◽  
Blood Cells ◽  
Morphological Changes ◽  
White Blood Cells ◽  
Haemoglobin Concentration ◽  
In Vivo Studies ◽  
Mean Cell Volume ◽  
Distribution Width

ObjectivesDespite the increasing availability of feline blood collected and stored for transfusion purposes, few studies have been performed on feline blood units. The aim of this prospective in vitro study was to evaluate haematological and morphological changes in feline blood cells in whole blood units between collection and end of storage.MethodsHaematological examination (red blood cells [RBCs], haemoglobin, haematocrit, red cell distribution width, mean cell volume, mean cell haemoglobin concentration, mean cell haemoglobin, white blood cells [WBCs] and platelet [PLT] count) was performed on 40 non-leukoreduced feline whole blood units at the time of collection (day[D]0) and after storage (D35). The blood was collected into citrate–phosphate–dextrose–adenine anticoagulant-preservative solution using an open system in a veterinary blood bank and stored for 35 days at 4 ± 2°C. Twenty of these feline whole blood units were also analysed for blood cell morphology (normal RBCs, macrocytes, echinocytes, spherocytes, schistocytes, lysed RBCs, RBCs with Heinz bodies and recognisable WBC and PLT count). Differences between the two examination times were statistically analysed.ResultsThere was a statistically significant decrease in WBC and PLT counts after storage at D35 ( P <0.0001 for both). The most significant cellular morphological changes after storage were an increase in echinocyte count ( P = 0.0001), and lysed RBCs ( P <0.0001), and a decrease in normal RBCs ( P <0.0001). Recognisable WBCs – mainly lymphocytes – were present at the end of storage.Conclusions and relevanceThis study showed that significant morphological changes occur in RBCs in feline blood units during storage for 35 days. In vivo studies are required to establish if these changes could affect the ability of stored RBCs to circulate and provide adequate oxygen delivery after transfusion.

scholarly journals Quantifying the biophysical characteristics of Plasmodium-falciparum-parasitized red blood cells in microcirculation

2010 ◽  
Vol 108 (1) ◽  
pp. 35-39 ◽  
Author(s):  
D. A. Fedosov ◽  
B. Caswell ◽  
S. Suresh ◽  
G. E. Karniadakis
Keyword(s):  
Plasmodium Falciparum ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Three Dimensional ◽  
Quantitative Agreement ◽  
In Vivo Studies ◽  
Cell Dynamics ◽  
Sudden Transition

The pathogenicity of Plasmodium falciparum (Pf) malaria results from the stiffening of red blood cells (RBCs) and its ability to adhere to endothelial cells (cytoadherence). The dynamics of Pf-parasitized RBCs is studied by three-dimensional mesoscopic simulations of flow in cylindrical capillaries in order to predict the flow resistance enhancement at different parasitemia levels. In addition, the adhesive dynamics of Pf-RBCs is explored for various parameters revealing several types of cell dynamics such as firm adhesion, very slow slipping along the wall, and intermittent flipping. The parasite inside the RBC is modeled explicitly in order to capture phenomena such as “hindered tumbling” motion of the RBC and the sudden transition from firm RBC cytoadherence to flipping on the endothelial surface. These predictions are in quantitative agreement with recent experimental observations, and thus the three-dimensional modeling method presented here provides new capabilities for guiding and interpreting future in vitro and in vivo studies of malaria.

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