THE RELEASE IN VITRO OF VASOPRESSIN UNACCOMPANIED BY THE AXOPLASMIC ENZYMES: LACTIC ACID DEHYDROGENASE AND ADENYLATE KINASE

1973 ◽  
Vol 72 (3) ◽  
pp. 417-424 ◽  
Author(s):  
B. A. Edwards ◽  
M. E. Edwards ◽  
N. A. Thorn
Keyword(s):  
Lactic Acid ◽  
Adenylate Kinase ◽  
Potassium Concentration ◽  
Supernatant Fraction ◽  
High Potassium ◽  
Lactic Acid Dehydrogenase ◽  
Acid Dehydrogenase ◽  
High Potassium Concentration ◽  
Vasopressor Activity

ABSTRACT Lactic acid dehydrogenase (LDH) and adenylate kinase were shown by differential centrifugation to be mainly associated with the supernatant fraction of ox neurohypophyses. In vitro release of vasopressor activity, LDH and adenylate kinase from groups of rat neural hemilobes or slices of ox neurohypophyses was studied at rest and after stimulation with a high potassium concentration or after electrical stimulation. Although release of vasopressor activity increased considerably on stimulation, no significant change in the release of LDH or adenylate kinase could be detected. The findings are discussed in relation to the different hypotheses for the mechanism of release of vasopressin.

IN VITRO STUDIES OF THE RELEASE MECHANISM FOR VASOPRESSIN IN RATS.

1967 ◽  
Vol 56 (1) ◽  
pp. 139-145 ◽  
Author(s):  
P. Bie ◽  
N. A. Thorn
Keyword(s):  
Supraoptic Nucleus ◽  
Potassium Concentration ◽  
Nerve Endings ◽  
Release Mechanism ◽  
High Potassium ◽  
Paraventricular Nuclei ◽  
Pressor Activity ◽  
High Potassium Concentration ◽  
Vasopressor Activity

ABSTRACT Isolated pieces of rat hypothalamus containing the supraoptic and paraventricular nuclei, respectively, did not release vasopressin when incubated in a medium with a high potassium concentration, or in media containing acetylcholine, noradrenaline or sodium chloride in a hypertonic concentration. The average vasopressor activity that could be extracted from the supraoptic region was equivalent to 8 milli-units of vasopressin per 100 g rat, whereas extract of the paraventricular region contained little pressor activity. The results seem to be in accordance with the hypothesis that the first precursor(s) of vasopressin is synthesized predominantly in the supraoptic nucleus and that the neurosecretory granules go through a »maturation« process during their passage from the hypothalamus to nerve endings in the neurohypophysis. Not until they reach the nerve endings do they contribute to the formation of the pool from which the hormone may be easily mobilized.

scholarly journals INFLUENCE OF EXTERNAL POTASSIUM ON THE SYNTHESIS AND DEPOSITION OF MATRIX COMPONENTS BY CHONDROCYTES IN VITRO

1974 ◽  
Vol 63 (3) ◽  
pp. 843-854 ◽  
Author(s):  
Jon C. Daniel ◽  
Robert A. Kosher ◽  
James E. Hamos ◽  
James W. Lash
Keyword(s):  
Culture Medium ◽  
Hyaline Cartilage ◽  
Cell Layer ◽  
Potassium Concentration ◽  
Cartilage Matrix ◽  
High Potassium ◽  
External Potassium ◽  
Matrix Components ◽  
High Potassium Concentration

The effect of a high external potassium concentration on the synthesis and deposition of matrix components by chondrocytes in cell culture was determined. There is a twofold increase in the amount of chondroitin 4- and 6-sulfate accumulated by chondrocytes grown in medium containing a high potassium concentration. There is also a comparable increase in the production of other sulfated glycosaminoglycans (GAG) including heparan sulfate and uncharacterized glycoprotein components. The twofold greater accumulation of GAG in the high potassium medium is primarily the result of a decrease in their rate of degradation. In spite of this increased accumulation of GAG, the cells in high potassium fail to elaborate appreciable quantities of visible matrix, although they do retain the typical chondrocytic polygonal morphology. Although most of the products are secreted into the culture medium in the high potassium environment, the cell layer retains the same amount of glycosaminoglycan as the control cultures. The inability of chondrocytes grown in high potassium to elaborate the typical hyaline cartilage matrix is not a consequence of an impairment in collagen synthesis, since there is no difference in the total amount of collagen synthesized by high potassium or control cultures. There is, however, a slight increase in the proportion of collagen that is secreted into the medium by chondrocytes in high potassium. Synthesis of the predominant cartilage matrix molecules is not sufficient in itself to ensure that these molecules will be assembled into a hyaline matrix.

High potassium concentration accelerate pig sperm ability to penetrate oocytes in vitro

1994 ◽  
Vol 41 (1) ◽  
pp. 308
Author(s):  
K. Suzuki ◽  
T. Mori ◽  
M. Yamaguchi ◽  
H. Shimizu
Keyword(s):  
Potassium Concentration ◽  
High Potassium ◽  
High Potassium Concentration

Lactic acid dehydrogenase as a marker of renal injury during renal artery stenting

2009 ◽  
Vol 10 (3) ◽  
pp. 199
Author(s):  
Satjit Adlakha ◽  
Amanda Sinclair ◽  
Steven Haller ◽  
Pamela Brewster ◽  
Mark Burket ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Renal Artery ◽  
Renal Injury ◽  
Lactic Acid Dehydrogenase ◽  
Acid Dehydrogenase ◽  
Renal Artery Stenting

Lactic Acid Assay with L(+)lactic Acid Dehydrogenase from Rabbit Muscle

1963 ◽  
Vol 58 (2-3) ◽  
pp. 243-249 ◽  
Author(s):  
Lennart Lundholm ◽  
Ella Mohme-Lundholm ◽  
Nandor Vamos
Keyword(s):  
Lactic Acid ◽  
Rabbit Muscle ◽  
Lactic Acid Dehydrogenase ◽  
Acid Dehydrogenase
Sign in / Sign up

Export Citation Format

Share Document