Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study tried to improve the number of viable islets isolated from a pancreas because a sufficient number cannot be obtained when the organ is preserved in the manner used for pancreas transplantation. The mechanism involved in the decrease in islet yield during preservation was studied to try to develop a better method for islet preparation. First, the integrity of the ductal system was compared between fresh and 6-hr simply preserved (in Hanks' balanced salt solution) rat pancreases. The ductal pressure after ductal injection of HBSS reached a plateau earlier and was significantly lower for the preserved pancreases (0.073 +/- 0.026 min, 410 +/- 17 mmHg, n = 5) than for the fresh ones (0.176 +/- 0.086 min, 561 +/- 103 mmHg, n = 7, P less than 0.05). Second, the extent of pancreatic distention was examined following ductal injection of barium gelatin solution. Solution leakage occurred earlier and distention was less in the preserved pancreas. In addition, the gelatin was found in the capillaries within some islets of the preserved pancreas. These results indicated that the preservation led to a rapid loss of integrity of the ductal system before collagenase injection. We therefore tested the efficacy of ductal collagenase injection at the time of harvesting: 15 ml of 1.0 mg/ml collagenase HBSS was intraductally injected and the pancreas was preserved at 4 degrees C for 2, 4, 6, and 24 hr. The isolation procedure was similar to that used for the fresh pancreas. The yield was significantly better than that of the simply preserved pancreas at 4 hr (241 +/- 22, n = 3, vs. 140 +/- 58, n = 3, P less than 0.05) and at 6 hr (171 +/- 58, n = 14, vs. 32 +/- 33, n = 6, P less than 0.01). These isolated islets were spherical-oval and their viability was confirmed by the ability to reverse STZ-induced diabetes in mice. These results indicated that the integrity of the ductal system, which is necessary for distention of the whole pancreas, was lost during preservation. To solve this problem, ductal collagenase injection should be done at the time of pancreas harvesting and then followed by simple preservation. This method is recommended to obtain viable islets from a preserved pancreas.
 ...
PMID:Improvement in islet yield from a cold-preserved pancreas by pancreatic ductal collagenase distention at the time of harvesting. 184 29

In an attempt to develop an improved method for preserving the pancreas prior to islet isolation, the effects of warm and cold ischemia were examined on rat pancreases, from which reproducible high yields of islets can be obtained when fresh. Both warm and cold preservation rapidly decreased islet yield. Use of Hanks' or modified Sacks' solution also led to marked decrease in islet yield. After 6 hrs of preservation, the islet yield was 1/5-1/10 of those of fresh pancreases (374 +/- 74, n = 14), and no islets were obtained after 24 hrs of preservation regardless of the preservation solution. Monitoring of ductal pressure during forced injection of Hanks' solution in 6 hrs-preserved pancreas with HBSS showed a significantly earlier and lower peak of pressure than those of fresh pancreases. On the other hand, simple hypothermic preservation after pancreatic ductal distention with collagenase Hanks' solution at the time of harvesting resulted in a significantly higher islet yield up to 6 hours (171 +/- 58, n = 14, P less than 0.01), as compared with conventional methods. The viability of the islets isolated by this method was confirmed by the ability to restore normoglycemia of STZ-induced diabetic B6 mice on transplantation of 400 islets in the renal subcapsular space. These findings indicated that loss of the integrity of the ductal system against forced collagenase injection during cold preservation led to poor distention and digestion of the pancreas, ductal collagenase injection at the time of pancreas harvesting followed by simple preservation is recommended to obtain viable islets from the preserved pancreas.
 ...
PMID:Successful islet isolation from preserved rat pancreas following pancreatic ductal collagenase at the time of harvesting. 196 77

We have been stressing the advantage of stationary digestion because of its simplicity and reproducible high yields of viable islets. In the present study optimal conditions of stationary in vitro collagenase digestion in mice and rats were examined. We also compared two possible routes for collagenase injection; ductal (PD) and portal venous (PV) based on subsequent islet yield and ability to reverse diabetes in rats. Three parameters which affect the quality of digestion are 1) collagenase concentration, 2) incubation time and 3) digestion temperature. Suitable conditions were easily determined and reproducible high yield of islets could be consistently obtained. The islets from one mouse pancreas (approximately 200 islets) could consistently restore normoglycemia in one STZ-induced diabetic mouse and the islets from one rat pancreas (500-600 islets) can restore normoglycemia in 5-6 STZ-induced diabetic mice within a couple of days. Islet yield in the PD method was greater than that in the PV method, and insulin release from PD islets in response to high glucose was well preserved after 24 hours of culture when compared to PV islets. The ability to restore normoglycemia in STZ-induced diabetic mice was well preserved when transplanting 100 PD islets as compared with the same number of PV islets. The PD islets revealed a well preserved structure with healthy endocrine cells, while the PV islets showed a dilated capillary network and distorted endocrine cell continuity. Histological examination of digested tissue following PD injection showed the complete destruction of pancreatic exocrine tissue, as well as mechanical separation and digestion of interstitial tissue between the islets and exocrine tissue, with the islet being preserved selectively intact.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Crucial role of pancreatic ductal collagenase injection for isolation of pancreatic islets. 196 78

Characteristics of lipoprotein receptors of the isolated liver parenchymal cells prepared from the streptozotocin-induced diabetic rats were investigated. Streptozotocin-induced diabetic rats fed 1.0% cholesterol showed the exaggerated hypercholesterolemia as compared to control rats fed 1.0% cholesterol. The present study was designed to elucidate the role of lipoprotein receptor mechanisms of liver parenchymal cells in the diabetic dyslipoproteinemia. 125I-labeled lipoproteins (rat beta-VLDL, human LDL2 or rat HDL3) were incubated with liver parenchymal cells isolated by liver perfusion using collagenase. According to the Scatchard analysis, the apparent dissociation constant (kd) and maximum beta-VLDL binding (Bmax) for the higher affinity binding site in the diabetic rats (n = 6) were (11.9 +/- 5.1) X 10(2) ng/ml and 307.5 +/- 145.2 ng/10(6) cells, respectively. These binding characteristics of the diabetic rats were not significantly different from the control rats. Furthermore, there were no significant differences in the binding characteristics of human LDL2 and rat HDL3 between the diabetic rats and the control rats. The data presented suggest that significant role of alteration of lipoprotein receptor characteristics in liver parenchymal cells is not played in the diabetic dyslipoproteinemia.
 ...
PMID:Characteristics of lipoprotein receptors of the isolated liver parenchymal cells prepared from the streptozotocin-induced diabetic rats. 300 89

Using islets obtained by collagenase digestion, we have carried out a longitudinal study of the ultrastructure of endocrine cells of the islets of Langerhans from C57BL/6 mice, during the development of diabetes induced by the multiple low-dose streptozotocin (mld STZ) technique, with and without co-treatment with complete Freund's adjuvant (CFA). Diabetes, as assessed by glycemia, occurred on different days in the various treatment groups following the initial STZ injection. It was observed on day 7 in 4/7 and 3/7 animals treated with mld STZ and with CFA plus mld STZ respectively, on day 14 in 3/6 animals treated with CFA plus sub mld STZ and on day 21 in 2/5 animals treated with sub mld STZ. Breakages in the basement membrane of the B-cell, and severe vacuolation, occurred in all STZ treated animals, despite normoglycemia in animals in the sub-mld group. Mononuclear cells (macrophages acutely and lymphocytes chronically) were observed in islets from animals with mld STZ irrespective of treatment with CFA, but were found adjacent to acinar cells only in those animals treated with CFA. Damage to acinar cells was observed exclusively in this group. In sub mld STZ treated animals, mononuclear cells were found only in those animals treated with CFA. These findings are discussed with reference to the etiopathology of the disease.
 ...
PMID:A longitudinal ultrastructural study of pancreatic cellular damage in murine streptozotocin diabetes. 307 Oct 64

The sensitivity to lipolytic agents is altered in diabetic vs. control animals. Because of its role as a diabetogenic hormone and its ability to elicit lipolysis, GH was studied in isolated fat cells (IFC) from control and streptozotocin-diabetic (STZ-DM) rats. IFCs from the epididymal fat of 150 to 200-g normal and STZ-DM Holtzman rats were prepared by collagenase digestion. Lipolysis was measured by glycerol release after either incubation or perifusion with the following concentrations: epinephrine (EPI), 0.01-0.1 microM; theophylline, 0.01-1.0 mg/ml; adenosine deaminase (ADA), and bovine GH (bGH), 0.01-1.0 microgram/ml. Rats, rendered diabetic by STZ (65 mg/kg), were used on day 3. In a dose-response study comparing glycerol release from control and STZ-DM IFC, IFC were preincubated with 1.0 microgram/ml bGH and then incubated with varying concentrations of EPI or bGH. In STZ-DM, we noted increased lipolytic sensitivity to low concentrations of EPI or bGH. Furthermore, in perifusion, STZ-DM IFC did not require obligatory preincubation with bGH for optimal glycerol release. The addition of ADA increased glycerol release from incubated IFC (STZ-DM and controls). In both systems an enhanced lipolytic response to theophylline was seen in the presence of bGH in control and STZ-DM. It was thus concluded that IFC from normal animals do not respond to GH without preincubation. IFC from STZ-DM rats show a lipolytic response to GH without preincubation. Preincubation with GH increases the lipolytic response of IFC from STZ-DM to all lipolytic agents compared to control responses. In addition, ADA greatly enhanced lipolysis in IFC from STZ-DM compared to that in controls. Together these data demonstrate enhanced sensitivity to both lipolytic stimuli and adenosine suppression of lipolysis in IFC from STZ-DM.
 ...
PMID:Lipolysis in diabetic adipocytes: differences in response to growth hormone and adenosine. 362 74

This study compares the drugs Streptozotocin (STZ) and Alloxan (ALN) in the diabetic wound healing model to determine the effect of their diverse immunologic and metabolic activity upon wound collagen and collagenase. Levels of hydroxyproline (as a measure of collagen) and collagenase were determined in polytetrafluorethylene (PTFE) wound cylinders harvested from STZ and ALN-diabetic rats and nondiabetic controls on post-operative days 5, 10 and 20. Animals treated with STZ and ALN had significantly less hydroxyproline on day 5 compared to control rats (p < 0.05). However, no difference was noted on days 10 and 20 between these two agents and controls, or between STZ and ALN at any time in the experiment. Despite their markedly dissimilar side effects, we conclude that either drug is appropriate in the diabetic wound healing when determining wound collagen and collagenase activity in this setting.
 ...
PMID:Streptozotocin and alloxan are comparable agents in the diabetic model of impaired wound healing. 771 79

In a series of experiments on syngeneic rat islet (pancreatic fragments) transplantation we demonstrate that direct hepatic transplantation is successful to alleviate streptozotocin induced diabetes with tissue from a single donor. The experimental groups were: recipients of fresh, and cryopreserved pancreatic fragments. The fresh graft was prepared by collagenase digestion. Cryopreserved fragments were further treated by a standard freeze-thaw protocol which consists of slow cooling at 0.3 degrees C/min to -75 degrees C followed by transfer to -196 degrees C, in the presence of 1.4 M Me2SO, and storage at this temperature for one day or 1 wk, and then warming them back to room temperature at a rate of 35 degrees C/min. Streptozotocin-induced diabetes in rats can be reversed by injection of isolated pancreatic fragments from a single donor directly into the liver. No significant difference was observed between the recipients receiving fresh or cryopreserved tissue for 1 day or 1 wk. It is possible that elaborate purification itself is not conducive to successful alleviation of diabetes. This would corroborate the hypothesis that trophic factors are present in impure fragments. The direct infusion of islet fragments into the liver could allow for percutaneous administration in human transplantation.
 ...
PMID:Single donor transplantation of fresh and cryopreserved pancreatic fragments into the liver parenchyma in syngeneic rats. 782 82

To reassess the accumulation of advanced glycation end products in diabetic renal cortex, we used a newly developed enzyme-linked immunosorbent assay to measure AGEs in renal cortex from STZ-induced diabetic and age-matched control rats. Kidneys and aortas were obtained from rats after 5 and 20 wk of STZ injection. At 5 wk of diabetes, the mean AGE content in collagenase-digested materials of renal cortex was > 16-fold higher in diabetic animals compared with controls (1044.4 +/- 151.8 vs. 64.3 +/- 5.7 arbitrary units, P < 0.01). At 20 wk of diabetes, it was > 45-fold higher in diabetic compared with control animals (3841.0 +/- 1077.3 vs. 83.8 +/- 12.8 AUs, P < 0.01). These increases were surprisingly large compared with the < 1.5-fold increase in the fluorescence levels both after 5 and 20 wk of diabetes. In control animals, neither the AGE content nor the fluorescence level increased during this period. Moreover, at 20 wk of diabetes, the AGE content was 39-fold higher in renal cortex compared with aorta. This study provided the first immunochemical evidence that collagenase-digested materials of renal cortex, as well as aorta, contained AGE products and that these products were present in much higher levels in diabetic animals than in control animals. With duration of diabetes, the AGE contents increased significantly both in renal cortex and aorta. The excessive accumulation of AGEs was most apparent in the diabetic kidney.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Immunochemical detection of advanced glycation end products in renal cortex from STZ-induced diabetic rat. 849 6

Streptozotocin-treated C57B1/SJL mice developed glomerular hypertrophy and light microscopic lesions mimicking human diabetic glomerulosclerosis. In contrast, there were no glomerular hypertrophy and lesions in diabetic mice transgenic (TG) for a mutated growth hormone (bGH-G119K) that competes with native endogenous GH and results in dwarfism. We examined the molecular events underlying these findings. The non-transgenic (non-TG) diabetic mouse glomeruli had an increase in mRNA coding for alpha 1IV collagen, laminin B1, TGF-beta 1, 72 kDa collagenase, and TIMP-3. In contrast, glomerular type IV collagen and laminin B1 mRNA levels were normal in diabetic TG dwarf mice. However, the 72 kDa gelatinase, TIMP-3, and TGF-beta 1 mRNAs were elevated in the diabetic dwarfs. Type IV collagen and laminin accumulated in the glomeruli of diabetic non-TG, but not of diabetic dwarf mice, by immunofluorescence microscopy, confirming the mRNA data. GH binding protein mRNA levels were comparable in glomeruli from dwarf and non-TG mice, both diabetic and non-diabetic. We did not detect GH receptor mRNA in glomeruli. These data suggest that diabetic glomerulosclerosis is associated with an increase in type IV collagen and laminin synthesis, and that these changes do not occur in mice transgenic for bGH119K, a functional antagonist of GH. The increase of 72 kDa gelatinase, TIMP-3 and TGF-beta 1 mRNAs, independent of GH, suggested that these changes induced by hyperglycemia were not sufficient for the induction of glomerulosclerosis.
 ...
PMID:Inhibition of diabetic nephropathy by a GH antagonist: a molecular analysis. 884 Feb 79


1 2 Next >>