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Biomedical subjects

C Stock

Publications and source records attributed to C Stock.

At least 55 records · Page 3Linked to original sources
PubMed1977

On the secretagogue effect of dibutyryl cyclic AMP in the rat exocrine pancreas.

DbcAMP greater than or equal to 0.1 mM induces the discharge of exportable enzymes from rat pancreas fragments incubated in vitro. This effect is qualitatively similar to the action of physiological secretagogues acting via hormone receptors: 1) it is accompanied by the appearance of exocytotic images at the acinar cell apex; 2) it is energy dependent but energy supply is low while that required for the carbamylcholine or caerulein response is high and can only be afforded by oxidative phosphorylation; 3) it is calcium dependent, but no alteration of inward or outward calcium movement can be observed; 4) it is altered by agents known to disrupt the microfilamentous microtubular system [41]. However, the secretory response to DbcAMP is quantitatively less than that obtained with hormonal stimuli. A damaging effect of DbcAMP on pancreatic acinar cells is ruled out on histological and biochemical grounds: there is no significant leakage of LDH; protein synthesis, 2-deoxy-D-glucose and L-leucine uptake are unaltered. The secretagogue effect of DbcAMP is reversible, dose-related and specific. It is not mediated by neurotransmitter release or by interaction with their receptors. The evidence presented points to a direct interaction of DbcAMP on the pancreatic acinar cell and suggests the last step of the secretory cycle as the most probable site of action of the nucleotide derivative.

Adrenergic Agonists↗
PubMed1977

Effect of vinblastine on pancreatic enzymes secretion induced by cyclic nucleotide derivatives.

Vinblastine did not affect the basal secretion of enzymes from the rat pancreas, but it potentiates the secretory response to dibutyryl cyclic AMP. This potentiation is confirmed by the observation of numerous pictures of exocytosis at the apical part of the acinar cell. Dibutyryl cyclic GMP by itself, or associated with vinblastine, failed to modify the spontaneous release of enzymes or the secretion induced by dibutyryl cyclic AMP.

Amylases↗
PubMed1976

[Double-blind study for the prevention of postoperative thrombosis].

In a double-blind study a randomized group of 96 patients with abdominal operations received a placebo, dipyridamol/acetylsalicylic acid or ASA alone. Thrombi were verified by the 125-I-fibrinogen test. In 38% of the placebo group deep venous thrombosis (DVT) was found, while only 10% of the dipyridamol/ASA group (P less than 0,05) and 28% of the ASA treated patients (not significant) showed radioactive thrombi. DVT were localized in 83.8% in the calf region. 48.6% of increasend activities were registered up to the end of the first postoperative day, 78.3% up to the third day. The results emphasize the importance of a general antithrombotic prophylaxis. Dipyridamol/ASA seems to be efficient in this regard for abdominal procedures.

Abdomen↗
PubMed1975

Microfilamentous system and secretion of enzyme in the exocrine pancreas. Effect of cytochalasin B.

The microfilaments in the acinar cell of the exocrine pancreas are essentially located in the apical part of the cell: thin microfilaments (50 A), cytochalasin B (CB)-sensitive, form the axis of the microvilli and a network lying beneath the apical membrane; thicker filaments (100 A), at least partly CB-insensitive, form bundles parallel to the plasma cell membrane and the desmosomal links. CB interaction with the acinar cell of the exocrine pancreas involves at least two sites: a membrane site involved in the inhibitory effect of CB on the monosaccharide transport and a less sensitive site at the filamentous level at least partly responsible for the inhibitory effect of CB in the secretion of the exportable enzyme from the pancreatic cell. CB did not alter the energy balance of the acinar cell nor the exchanges of 15-Ca between the extracellular medium and the pancreatic tissue. CB (2 times 10-minus 7 and 2 times 10-minus 6 M) has secretagogue properties whereas CB (2 times 10-minus 5 M) has inhibitory effect on stimulated secretion and secretagogue properties. The mechanism of these secretory effects is not yet explained. The analysis presented in this investigation affords strong evidence for the involvement of the microfilamentous network in the last steps of the secretory cycle in the acinar cell of the exocrine pancreas.

Adenosine Triphosphate↗
PubMed1975

[Renal preservation: comparative effectiveness of 2 simple perfusion technics].

The authors compare the efficacy of two perfusates, Collins' solution and Perfudex, for conservation of kidneys for short periods by perfusion and hypothermic immersion. 22 dog kidneys, removed by lombotomy, were preserved for 24 hours with one or other of these solutions and then re-implanted into their host. Radio-isotopic renography, the uptake of Hg 197 Cl3 and a hippuran renogram, used to assess the function of the transplants, suggested the functional superiority of kidneys preserved with Collins solutions. Histological controls carried out beyond the 10 th post-operative week, confirmed these results. The correlations observed between these various findings also assessed the reliability of radio-isotope examinations in the exploration of renal function.

Animals↗
PubMed1975

[Existence of cytoplasmic inclusions in acinic cells of the exocrine pancreas of the hyperglycemic obese mouse].

Peculiar cytoplasmic inclusions with crystalline pattern are described in the obese hyperglycaemic mouse pancreas acinar cells. They are generally associated with filamentous structures. However, crystalline and filamentous inclusions have also been observed in isolated forms. These inclusions are not digested by pronase. Since they have also been encountered in normal mice, it seems that the hyperglycaemic syndrome does not play a role in inducing their formation.

Acid Phosphatase↗