scholarly journals The effect of high-protein and high-carbohydrate diets on [125I]iodoinsulin binding in skeletal muscle plasma membranes and isolated hepatocytes of rainbow trout (Salmo gairdneri)

1983 ◽  
Vol 50 (1) ◽  
pp. 129-139 ◽  
Author(s):  
Richard F. Ablett ◽  
Matthew J. Taylor ◽  
Daniel P. Selivonchick
Keyword(s):  
Skeletal Muscle ◽  
Rainbow Trout ◽  
Plasma Membranes ◽  
Dissociation Constants ◽  
Specific Binding ◽  
Isolated Hepatocytes ◽  
High Protein ◽  
Salmo Gairdneri ◽  
Binding Studies ◽  
High Carbohydrate

1. [125I]iodoinsulin-binding studies in the presence of a concentration range of bovine insulin were conducted to establish specific insulin-binding levels in skeletal muscle plasma membranes and isolated hepatocytes of rainbow trout (Salmo gairdneri) reared on control, high-protein or high-carbohydrate diets.2. Negative co-operativity was observed and receptor concentrations and apparent dissociation constants established for each preparation.3. No differences of specific binding attributed to diet were detected in skeletal muscle plasma membrane preparations; however, the receptor concentration of isolated hepatocytes from high-carbohydrate-reared trout was increased. This contrasted to comparable mammalian studies.

scholarly journals The effect of dietary composition and of insulin on gluconeogenesis in rainbow trout (Salmo gairdneri)

1977 ◽  
Vol 38 (3) ◽  
pp. 385-395 ◽  
Author(s):  
C. B. Cowey ◽  
M. De La Higuera ◽  
J. W. Adron
Keyword(s):  
Rainbow Trout ◽  
High Protein Diet ◽  
High Carbohydrate Diet ◽  
High Protein ◽  
Protein Diet ◽  
Salmo Gairdneri ◽  
Carbohydrate Diet ◽  
Commercial Diet ◽  
High Carbohydrate ◽  
Gluconeogenesis From Alanine

1. The activities at 15° of three gluconeogenic enzymes, d-fructose-1,6-diphosphate, 1-phosphohydrolase (EC 3.1.3.11), pyruvate carboxylase (EC 6.4.1.1) and phosphoenolpyruvate carboxykinase (4.1.1.32), were determined in liver, kidney, gill and muscle of rainbow trout (Salmo gairdneri) given a commercial diet. The results indicated that liver and kidney are the main sites of gluconeogenesis.2. Glucose formation from pyruvate was approximately 6 μmol/h per g wet weight at 15° in liver slices of trout given a commercial diet.3. Glucose diffusion space in trout was measured by the dilution principle after intravascular injection of a trace dose of [U-14C]glucose. Glucose space was found to be 13.7% of the body-weight. Gluconeogenesis in vivo amounted to approximately 45 μmol/kg body-weight per h.4. Intraperitoneally injected [U-14C]alanine was quickly converted to glucose. Maximal incorporation of alanine into glucose occurred 6 h after alanine administration.5. Rainbow trout given a high-protein diet gained in weight significantly during a 4-week period. Those given a high-carbohydrate diet did not make a significant weight gain over the same period. Gluconeogenesis from alanine was markedly reduced in fish given the high-carbohydrate diet. There was no significant difference in gluconeogenesis from alanine in fish given a high-protein diet and fish which were fasted for 21 d.6. Gluconeogenesis from alanine in trout was suppressed by intravenous injection of insulin. This effect was found both in trout given a high-protein diet and in fasted trout.

Adrenergic receptors on cerebral microvessels: pericyte contribution

1989 ◽  
Vol 256 (1) ◽  
pp. R224-R230 ◽  
Author(s):  
R. M. Elfont ◽  
P. R. Sundaresan ◽  
C. D. Sladek
Keyword(s):  
Endothelial Cells ◽  
Binding Sites ◽  
Adrenergic Receptors ◽  
Radioligand Binding ◽  
Dissociation Constants ◽  
Specific Binding ◽  
Binding Studies ◽  
Cerebral Microvessels ◽  
Beta Adrenoceptor ◽  
Number Of Binding Sites

R224-R230, 1989.--[125I]iodocyanopindolol ([125I]ICYP) and [3H]rauwolscine were used to quantitate, respectively, the beta- and alpha 2-adrenergic receptors in freshly isolated bovine cerebral microvessels and in pericyte cultures derived from these microvessels. Morphological and immunocytochemical criteria distinguished the pericytes from endothelial cells. Competitive binding studies established the specificity of the radioligand binding. The maximal number of binding sites (Bmax) for [125I]ICYP in the pericytes constituted only 8% of that in the microvessels (3.5 +/- 1.3 vs. 44.4 +/- 6.6 fmol/mg protein). In contrast, the Bmax for [3H]rauwolscine in the pericytes was 50% of that in the microvessels (55.4 +/- 11.8 vs. 111.1 +/- 9.5 fmol/mg protein). The dissociation constants for both [125I]ICYP and [3H]rauwolscine were similar in the two preparations. No alpha 1-adrenergic receptors, as defined by the specific binding of [3H]prazosin, were identified either in the pericytes or microvessels. Overall, our results suggest that pericytes contribute minimally to the total beta-adrenoceptor number of cerebral microvessels, and thus the beta-adrenoceptors must be located predominantly on endothelial cells. However, the contribution of pericytes to the total alpha 2-adrenoceptor number of the microvessels may be substantial.

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