scholarly journals Sulfate Uptake and Somatomedin Levels in the 'Little' (lit/lit) Mouse

1981 ◽  
Vol 34 (2) ◽  
pp. 221 ◽  
Author(s):  
NeiI M McKern ◽  
Donald B Cheek ◽  
WGordon Crewther
Keyword(s):  
Growth Hormone ◽  
Costal Cartilage ◽  
Fresh Medium ◽  
Bovine Growth Hormone ◽  
Consistent Difference ◽  
Sulfate Uptake ◽  
Low Levels ◽  
In Vivo Uptake

The mutant 'little' (lit/lit) mouse is deficient in growth hormone and has correspondingly low levels of serum somatomedin. Injection of these mice with human or bovine growth hormone significantly r(l.ises serum somatomedin levels within 6 h. In vivo uptake of radioactive sulfate by costal cartilage in lit/lit mice is similar to that of normal mice, which is unexpected in view of the low levels of circulating somatomedin. If costal cartilages from normal and lit/lit mice are preincubated in medium 199 in vitro before transfer to fresh medium containing radioactive sulfate and serum, there is no consistent difference in uptake of sulfate, demonstrating similar endogenous cartilage activity. In contrast, omission of the preincubation step reveals a lower uptake of sulfate in vitro by cartilage from lit/lit mice as compared with normal mice. Cartilage removed from lit/lit mice 24 h after injection with growth hormone, however, takes up greater amounts of sulfate than cartilage from untreated normal mice.

EFFECTS OF GROWTH HORMONE, PROLACTIN AND THYROXINE ON BODY WEIGHT, SOMATOMEDIN-LIKE ACTIVITY AND IN-VIVO SULPHATION OF CARTILAGE IN HYPOPITUITARY DWARF MICE

1980 ◽  
Vol 85 (1) ◽  
pp. 35-47 ◽  
Author(s):  
A. T. HOLDER ◽  
M. WALLIS ◽  
P. BIGGS ◽  
M. A. PREECE
Keyword(s):  
Growth Hormone ◽  
Costal Cartilage ◽  
Tail Length ◽  
Bovine Growth Hormone ◽  
Dwarf Mouse ◽  
Dwarf Mice ◽  
Dose Dependent Increase ◽  
Dose Dependent ◽  
In Vivo Uptake

SUMMARY Hypopituitary dwarf mice were found to have reduced levels of serum somatomedin-like activity compared with normal mice of the Snell strain. Treatment with bovine growth hormone for 3 and 7 days resulted in growth without significantly increased levels of serum somatomedin-like activity, as detected by in-vitro uptake of 35SO42− into normal rat cartilage; only after treatment for 14 days was somatomedin activity significantly raised. However, treatment for 2 days with bovine growth hormone, bovine prolactin or thyroxine resulted in a dose-dependent increase in in-vivo uptake of 35SO42− into dwarf mouse costal cartilage; growth hormone and thyroxine did not act synergistically. Ten days of treatment with growth hormone promoted a dose-dependent increase in both growth (increased weight gain and tail length) and in-vivo uptake of 35SO42−. Increase in tail length was correlated with uptake of 35SO42−. Thus, in-vivo uptake of 35SO42− into dwarf mouse costal cartilage provides a sensitive method for detecting a dose-related effect of growth hormone.

scholarly journals Metabolic effects of the major component of bovine growth hormone

1971 ◽  
Vol 122 (5) ◽  
pp. 633-640 ◽  
Author(s):  
N. I. Swislocki ◽  
M. Sonenberg ◽  
M. Kikutani
Keyword(s):  
Growth Hormone ◽  
Deae Cellulose ◽  
Heterogeneous Material ◽  
Parent Material ◽  
Metabolic Effects ◽  
Sedimentation Equilibrium ◽  
Bovine Growth Hormone ◽  
Hormone Effects

Bovine growth hormone, subjected to DEAE-cellulose chromatography, yielded one major and several minor components. The various chromatographic fractions of bovine growth hormone were compared with the parent material for their ability to promote hormone effects in vivo and in vitro. The major component of bovine growth hormone was homogeneous by acrylamide-gel electrophoresis, rechromatography and sedimentation equilibrium. Its amino acid composition was similar to that of the parent hormone. The major component possessed all the qualitative activities present in the original heterogeneous material, including promotion of acute hypoglycaemia and hypolipaemia. In studies in vitro in adipose-tissue segments the major component of the hormone increased entry of glucose and its oxidation to CO2, conversion of glucose into glyceride glycerol, release of glycerol and incorporation of histidine into adiposetissue protein. Other chromatographic fractions of bovine growth hormone were not homogeneous and possessed some but not all of the metabolic activities attributed to the hormone preparations or its major component. Thus, the metabolic effects obtained with bovine growth-hormone preparations in vivo and in vitro can be obtained with the major homogeneous component of the hormone. This observation precludes the possibility that the metabolic effects obtained with bovine growth-hormone preparations are due to the combined actions of a number of components found therein.

Bovine growth hormone fragment (1–133) has in-vitro somatomedin-like activity

1983 ◽  
Vol 96 (2) ◽  
pp. 195-199 ◽  
Author(s):  
J. P. Liberti ◽  
L. A. Durham
Keyword(s):  
Growth Hormone ◽  
Amino Acid ◽  
Costal Cartilage ◽  
Peptide Bond ◽  
Biologically Active ◽  
The Other ◽  
Bovine Growth Hormone ◽  
Amino Acid Residues ◽  
In Vitro Uptake

Thrombin digestion of bovine growth hormone (1–191) resulted in cleavage of the peptide bond between amino acid residues 133 and 134. Native growth hormone and purified peptides (1–133) and (134–191) were assayed for somatomedin-like activity. Peptide (1–133), ranging in concentration from 0·15–15 nmol/l, stimulated in-vitro uptake of [3H]thymidine by rat costal cartilage. None of the other peptides was biologically active.

scholarly journals Comparison of Sulfate Metabolism in Costal Cartilage of Normal and 'Little' Mice

1983 ◽  
Vol 36 (3) ◽  
pp. 263 ◽  
Author(s):  
NeiI M McKern
Keyword(s):  
Growth Hormone ◽  
Growth Rate ◽  
Body Weight ◽  
Costal Cartilage ◽  
Cartilage Degradation ◽  
Skeletal Growth ◽  
Sulfate Uptake ◽  
Sulfate Metabolism ◽  
C 50

C57BL/6J and mutant 'little' (lit/lit) mice c. 50 days of age were injected with doses of [35S]sulfate proportional to their body weight. Despite the diminished growth rate of lit/lit mice compared with normal mice at this age, uptake of radioactivity per unit mass of cartilage was similar for both mouse types, confirming previous data. Additional experiments with these mice established that the similarity of sulfate uptake could not be accounted for by differences in the location of bound sulfate or (for females) by differences in cartilage cellularity. Investigation of sulfate loss by costal cartilage in vivo indicated that cartilage degradation occurred at a greater rate in lit/lit mice than in normally growing mice. These latter data suggest that growth hormone, which is lacking in lit/lit mice, may in part regulate skeletal growth (at least for female mice) by inhibiting degradation of cartilage.

Active transport of calcium by intestine: effects of hypophysectomy and growth hormone

1962 ◽  
Vol 203 (5) ◽  
pp. 873-880 ◽  
Author(s):  
James D. Finkelstein ◽  
David Schachter
Keyword(s):  
Growth Hormone ◽  
Active Transport ◽  
Electrical Potential ◽  
Potential Gradient ◽  
Initial Increase ◽  
Bovine Growth Hormone ◽  
Hypophysectomized Rats ◽  
Rat Duodenum

The effects of hypophysectomy on active transport of calcium in vitro by everted gut sacs of rat duodenum are 1) an initial increase 4–5 days postoperatively and 2) a marked decrease 2–3 weeks postoperatively. The defect in transport results from reduction in the unidirectional transfers of Ca toward the serosa, and both steps in the transport (mucosal uptake and transfer to serosal surface) are impaired. Hypophysectomy also decreases iron transport (duodenal gut sacs), decreases l-proline transfer less strikingly (ileal gut sacs), increases d-galactose transport (jejunal gut sacs), and does not appear to influence either the electrical potential gradient from mucosa to serosa or the net flux of sodium. Treatment of hypophysectomized rats with a preparation of bovine growth hormone restores transfer mechanisms for calcium and iron. Ovine prolactin is also active in restoring the Ca mechanism, whereas other pituitary and nonpituitary hormones are not. Cortisone, l-thyroxin, and estradiol decrease Ca transport further in hypophysectomized rats. Absorption of Ca from loops of rat duodenum in vivo is also decreased 2 weeks after hypophysectomy and can be increased by prior treatment with bovine growth hormone.

Enhanced Increases in Cytosolic Ca2+ in ADP-Stimulated Platelets from Patients with Delta-Storage Pool Deficiency – A Possible Indicator of Interactions between Granule-Bound ADP and the Membrane ADP Receptor

1997 ◽  
Vol 77 (02) ◽  
pp. 376-382 ◽  
Author(s):  
Bruce Lages ◽  
Harvey J Weiss
Keyword(s):  
Platelet Rich Plasma ◽  
Limited Range ◽  
Dense Granule ◽  
Receptor Desensitization ◽  
Fura 2 ◽  
Storage Pool ◽  
Low Levels ◽  
The Right

SummaryThe possible involvement of secreted platelet substances in agonist- induced [Ca2+]i increases was investigated by comparing these increases in aspirin-treated, fura-2-loaded normal platelets and platelets from patients with storage pool deficiencies (SPD). In the presence and absence of extracellular calcium, the [Ca2+]i response induced by 10 µM ADP, but not those induced by 0.1 unit/ml thrombin, 3.3 µM U46619, or 20 µM serotonin, was significantly greater in SPD platelets than in normal platelets, and was increased to the greatest extent in SPD patients with Hermansky-Pudlak syndrome (HPS), in whom the dense granule deficiencies are the most severe. Pre-incubation of SPD-HPS and normal platelets with 0.005-5 µM ADP produced a dose-dependent inhibition of the [Ca2+]i response induced by 10 µ M ADP, but did not alter the [Ca2+]i increases induced by thrombin or U46619. Within a limited range of ADP concentrations, the dose-inhibition curve of the [Ca2+]i response to 10 µM ADP was significantly shifted to the right in SPD-HPS platelets, indicating that pre-incubation with greater amounts of ADP were required to achieve the same extent of inhibition as in normal platelets. These results are consistent with a hypothesis that the smaller ADP-induced [Ca2+]i increases seen in normal platelets may result from prior interactions of dense granule ADP, released via leakage or low levels of activation, with membrane ADP receptors, causing receptor desensitization. Addition of apyrase to platelet-rich plasma prior to fura-2 loading increased the ADP-induced [Ca2+]i response in both normal and SPD-HPS platelets, suggesting that some release of ADP derived from both dense granule and non-granular sources occurs during in vitro fura-2 loading and platelet washing procedures. However, this [Ca2+]i response was also greater in SPD-HPS platelets when blood was collected with minimal manipulation directly into anticoagulant containing apyrase, raising the possibility that release of dense granule ADP resulting in receptor desensitization may also occur in vivo. Thus, in addition to enhancing platelet activation, dense granule ADP could also act to limit the ADP-mediated reactivity of platelets exposed in vivo to low levels of stimulation.

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.

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