scholarly journals A Depressant Effect of Adrenaline on the Rat Diaphragm

Nature ◽  
1951 ◽  
Vol 167 (4251) ◽  
pp. 653-653 ◽  
Author(s):  
K. A. MONTAGU
Keyword(s):  
Rat Diaphragm ◽  
Depressant Effect

Characterization of the neuromuscular block produced by clindamycin and lincomycin

1976 ◽  
Vol 54 (6) ◽  
pp. 937-944 ◽  
Author(s):  
J. M. Wright ◽  
B. Collier
Keyword(s):  
Neuromuscular Block ◽  
Active Form ◽  
Neuromuscular Blocking ◽  
Rat Diaphragm ◽  
Depressant Effect ◽  
Clinical Toxicity ◽  
Local Anaesthetic Effect ◽  
Nerve Muscle ◽  
Anaesthetic Effect

The site of neuromuscular blockade induced by clindamycin and lincomycin was studied on isolated nerve and nerve–muscle preparations. Clindamycin (3.6 × 10−3 M) but not lincomycin (up to 1.5 × 10−2 M) had a local anaesthetic effect on a frog desheathed nerve preparation. Clindamycin (8 × 10−4 M) and lincomycin (4 × 10−3 M) depressed the response of the rat diaphragm to nerve stimulation and to direct muscle stimulation in parallel. This indicated that the predominant neuromuscular blocking effect of these antibiotics was due to an effect on the muscle. Clindamycin was fivefold more potent than lincomycin in this effect, and the unionized form of both drugs was the active form. Lincomycin (4 × 10−3 M) but not clindamycin (8 × 10−4 M) also had some depressant effect on nerve–muscle transmission as indicated by the interaction of the effects of the antibiotics and d-tubocurarine. The significance of these findings is discussed in relation to the acute clinical toxicity of these antibiotics.

SENSITIVITY OF THE RAT DIAPHRAGM TO GROWTH HORMONE.

1967 ◽  
Vol 54 (4) ◽  
pp. 645-662 ◽  
Author(s):  
Å. Hjalmarson ◽  
K. Ahrén
Keyword(s):  
Growth Hormone ◽  
Inhibitory Effect ◽  
Rat Diaphragm ◽  
Intracellular Accumulation ◽  
Slight Effect ◽  
Kidney Capsule ◽  
Muscle Tissues ◽  
Hypophysectomized Rats ◽  
Isolated Rat

ABSTRACT The effect of growth hormone (GH) in vitro on the rate of intracellular accumulation of the non-utilizable amino acid α-aminoisobutyric acid (AIB) was studied in the intact rat diaphragm preparation. Bovine or ovine GH (25 μg/ml incubation medium) markedly stimulated the accumulation of AIB-14C by diaphragms from hypophysectomized rats, while there was no or only a very slight effect on diaphragms from normal rats. In diaphragms from rats with the pituitary gland autotransplanted to the kidney capsule GH in vitro stimulated the accumulation of AIB-14C significantly more than in diaphragms from normal rats but significantly less than in diaphragms from hypophysectomized rats. Injections of GH intramuscularly for 4 days to hypophysectomized rats made the diaphragms from these rats less sensitive or completely insensitive to GH in vitro. These results indicate strongly that the relative insensitivity to GH in vitro of diaphragms from normal rats is due to the fact that the muscle tissues from these rats has been exposed to the endogenously secreted GH. The results show that GH can influence the accumulation of AIB-14C in the isolated rat diaphragm in two different ways giving an acute or »stimulatory« effect and a late or »inhibitory« effect, and that it seems to be a time-relationship between these two effects of the hormone.

ANALYSIS OF THE BIPHASIC ACTION OF GROWTH HORMONE IN VITRO ON THE RAT DIAPHRAGM

1968 ◽  
Vol 57 (3_Suppl) ◽  
pp. S19-S35 ◽  
Author(s):  
Å. Hjalmarson
Keyword(s):  
Growth Hormone ◽  
Actinomycin D ◽  
Accumulation Rate ◽  
Inhibitory Effect ◽  
Bovine Growth Hormone ◽  
Rat Diaphragm ◽  
Dual Nature ◽  
Hypophysectomized Rats ◽  
D 20

ABSTRACT In vitro addition of bovine growth hormone (GH) to intact hemidiaphragms from hypophysectomized rats has previously been found to produce both an early stimulatory effect lasting for 2—3 hours and a subsequent late inhibitory effect during which the muscle is insensitive to further addition of GH (Hjalmarson 1968). These effects on the accumulation rate of α-aminoisobutyric acid (AIB) and D-xylose have been further studied. In presence of actinomycin D (20 μg/ml) or puromycin (100 μg/ml) the duration of the stimulatory effect of GH (25 μg/ml) was prolonged to last for at least 4—5 hours and the late inhibitory effect was prevented. Similar results were obtained when glucose-free incubation medium was used. Preincubation of the diaphragm at different glucose concentrations (0—5 mg/ml) for 3 hours did not change the GH sensitivity. Addition of insulin at start of incubation could not prevent GH from inducing its late inhibitory effect, while dexamethasone seemed to potentiate this effect of GH. Furthermore, adrenaline was found to decrease the uptake of AIB-14C and D-xylose-14C in the diaphragm, but not to change the sensitivity of the muscle to GH. Preincubation of the diaphragm for 3 hours with puromycin in a concentration of 200 μg/ml markedly decreased the subsequent basal uptake of both AIB-14C and D-xylose-14C, in the presence of puromycin, and abolished the stimulatory effect of GH on the accumulation of AIB-14C. However, the effect of GH on the accumulation of D-xylose-14C was unchanged. The present observations are discussed and evaluated in relation to various mechanisms of GH action proposed to explain the dual nature of the hormone.

ENHANCERS OF LIVER REGENERATION IN ONCOLOGICAL SURGERY

2021 ◽  
Vol 108 (Supplement_3) ◽  
Author(s):  
M Osorio Capitan ◽  
S Rose ◽  
I Novo Sukia ◽  
B Herrero de la Parte ◽  
I Ruiz Montesinos ◽  
...  
Keyword(s):  
Folic Acid ◽  
Liver Function ◽  
Liver Regeneration ◽  
Control Group ◽  
Depressant Effect ◽  
Oncological Surgery ◽  
Portal Branch ◽  
Treatment Control ◽  
Early Application ◽  
Mean Size

Abstract INTRODUCTION Chemotherapy hinders liver function and probably its regenerating capacity, forcing to delay it after surgery. Our objective has been to verify this effect in an experimental model and to see if a hepatotrophic agent can prevent it. MATERIAL AND METHODS Four groups of 6 WAG/RijHsd rats (males, 3-4 months) were submitted to ligation of the portal branch to the left lateral and left paramedian lobes. They were sacrificed 36 h later to quantify the percentage of liver corresponding to the ligated lobes (weight), the number of hepatocyte’s nuclei (nº/100 µm2) and their mean size (µm2). One group received no treatment (control); another folic acid (2.5 mg/kg ip, during surgery); other 5-Fluorouracil (5-FU 50 mg/kg ip 48 h before); and the fourth received folic&5-FU. RESULTS The animals treated with folic acid showed a greater number of hepatocyte’s nuclei (24.4 ± 2.77 vs 15.2 ± 1.51) and their mean size was also greater (121 ± 2.34 vs 111 ± 1.8). However, the reduction in weight of the ligated parenchyma was less than in control group (33.4 ± 1.08 vs 29.5 ± 1.08). 5-FU did not modify the number of nuclei (15.6 ± 18.4), although they were smaller in size (104 ± 1.7). The addition of folic acid to 5-FU increased the number of nuclei (21.7 ± 2.8) and normalized their size (111 ± 3.2). CONCLUSIONS 5-FU exerts a depressant effect on livers regeneration, and folic acid overcomes it. Thus, folic acid could allow early application of chemotherapy without affecting liver regeneration.

scholarly journals Insulin Stimulation of Amino Acid Uptake in Rat Diaphragm

1968 ◽  
Vol 243 (8) ◽  
pp. 1846-1853 ◽  
Author(s):  
L J Elsas ◽  
I Albrecht ◽  
L E Rosenberg
Keyword(s):  
Amino Acid ◽  
Amino Acid Uptake ◽  
Acid Uptake ◽  
Rat Diaphragm ◽  
Insulin Stimulation ◽  
Stimulation Of

scholarly journals Action of Insulin on Transport of l-Alanine into Rat Diaphragm in Vitro

1973 ◽  
Vol 248 (18) ◽  
pp. 6450-6455
Author(s):  
Thomas R. Riggs ◽  
K. Janet McKirahan
Keyword(s):  
Rat Diaphragm ◽  
Diaphragm In Vitro

scholarly journals PHOSPHATE METABOLISM OF THE ISOLATED RAT DIAPHRAGM

1951 ◽  
Vol 189 (1) ◽  
pp. 59-63
Author(s):  
Niels. Haugaard ◽  
Julian B. Marsh ◽  
William C. Stadie
Keyword(s):  
Phosphate Metabolism ◽  
Rat Diaphragm ◽  
Isolated Rat

scholarly journals Effect of denervation on the molecular forms of acetylcholinesterase in rat diaphragm.

1982 ◽  
Vol 257 (22) ◽  
pp. 13638-13644 ◽  
Author(s):  
P L Collins ◽  
S G Younkin
Keyword(s):  
Molecular Forms ◽  
Rat Diaphragm
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