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1.
The metabolic affects of anapriline, captopril, and clophelin were studied in the blood and liver homogenates ex vivo and in vitro in experiments on intact rats and rats with alloxan diabetes. Anapriline lowered the blood lactate content in rats with diabetes and intact rats, reduced the level of glycemia in animals with marked hyperglycemia. Captopril increased the blood insulin and lactate content in rats with diabetes and the content of pyruvate in vivo. The results of the study show that the use of clophelin and anaprilin in the treatment of patients with diabetes mellitus is most rational.  相似文献   

2.
BACKGROUND: Clinical observations suggest that transplant coronary artery disease (TxCAD) is immunologically mediated but may be accelerated by metabolic derangements. We developed a rat model of heterotopic heart transplantation in the presence of diabetes and dyslipidemia to further study their role in TxCAD development. METHODS AND RESULTS: Major histocompatibility complex-mismatched strains of inbred rats underwent heterotopic heart transplantation (ACI-to-Lewis allografts). Diabetes (DM) was induced by streptozotocin injection (80 mg/kg) after transplantation; dyslipidemia was worsened by feeding of a 60% high-fructose diet (+F). Allograft transplants were divided into four groups: (1) +DM/+F; (2) +DM/-F; (3) -DM/+F; and (4) -DM/-F. Isograft transplants (Lewis to Lewis, +DM/+/-F) were controls. All animals received daily cyclosporine (5 mg/kg). Grafts surviving > 30 days were evaluated for TxCAD on histological sections and graded 0 to 5 for intimal thickness. All streptozotocin-treated animals were diabetic within 2 weeks, with fourfold increases in plasma glucose concentrations versus nondiabetics. Severe TxCAD was observed in diabetic allografts only. The mean grade of TxCAD in diabetic allografts was 3.2 +/- 0.5 versus 1.1 +/- 0.4 in diabetic isografts (P < 0.03) and zero TxCAD in nondiabetic allografts (P < or = 0.0001). Fructose feeding resulted in a 1.5-fold higher triglyceride and a 1.3-fold higher cholesterol level versus the regular diet (-F) but showed no independent contribution to the development of TxCAD. CONCLUSIONS: These findings suggest that metabolic derangements associated with diabetes play an important role in TxCAD development in heterotopic ACI-to-Lewis rat heart transplantation. In this model of TxCAD in major histocompatibility complex-mismatched, diabetic, and dyslipidemic rats, immunologic and metabolic mechanisms that contribute to TxCAD can be further delineated and approaches to its prevention assessed.  相似文献   

3.
It has been reported that immature rats subjected to cerebral hypoxia-ischemia sustain less brain damage if they are previously exposed to systemic hypoxia compared with animals not exposed to prior hypoxia. Accordingly, neuropathologic and metabolic experiments were conducted to confirm and extend the observation that hypoxic preconditioning protects the perinatal brain from subsequent hypoxic-ischemic brain damage. Six-day postnatal rats were subjected to systemic hypoxia with 8% oxygen at 37 degrees C for 2.5 h. Twenty-four hours later, they were exposed to unilateral cerebral hypoxia-ischemia for 2.5 h, produced by unilateral common carotid artery ligation and systemic hypoxia with 8% oxygen. Neuropathologic analysis, conducted at 30 days of postnatal age, indicated a substantial reduction in the severity of brain damage in the preconditioned rats, such that only 6 of 14 such animals exhibited cystic infarction, but all 13 animals without prior preconditioning exhibited infarction (p < 0.001). Measurement of cerebral glycolytic and tricarboxylic acid intermediates and high-energy phosphate reserves at the terminus of and at 4 and 24 h following hypoxia-ischemia showed no differences in the extent of alterations in the preconditioned and nonpreconditioned immature rats. A difference was seen in the restitution of high-energy stores during the first 24 h of recovery from hypoxia-ischemia, with a more optimal preservation of these metabolites in the preconditioned animals, reflecting the less severe ultimate brain damage. Accordingly, the neuroprotection afforded to the preconditioned animals was not the result of any differences in the extent of anaerobic glycolysis, tissue acidosis, or depletion in high-energy reserves during hypoxia-ischemia but rather the result of other mechanisms that improved the metabolic status of the immature brain during the early hours of reperfusion following hypoxia-ischemia.  相似文献   

4.
The role of adrenal cortex hormones in the development of vascular changes was studied in 16 rabbits with alloxan diabetes. Formation of morphological changes in the aorta proved to be partially determined by functional condition of the adrenal cortex at the early periods of alloxan diabetes.  相似文献   

5.
The androgen receptor (AR) was measured by an immunoblot assay in adult tissues of both male and female rats. Relatively high levels of AR were detected in tissues of the male urogenital tract and in the adrenal glands and gonads of both sexes. Another group of tissues, including the male levator ani/bulbocavernosus muscles, preputial gland, scrotal skin, and vagina, had low, but detectable, levels of AR. In a third group of tissues, including the uterus, kidney, spleen, liver, gut, heart, lung, pituitary, and hypothalamus, AR was undetectable. In some androgen target tissues, such as the penis, androgens cause an apparent disappearance of AR from the tissue, and in other tissues, such as the ventral prostate, androgen therapy increases the amount of detectable AR. We compared the effect of androgen on AR levels in the adrenal gland and ventral prostate, tissues that differ markedly in their trophic responses to androgen. Castration appeared to have no effect on the amount of detectable AR in the adrenal gland, whereas it caused a profound decrease in AR levels in the ventral prostate. By contrast, 7 days after hypophysectomy, AR levels declined in both the adrenal gland and the ventral prostate. The effects of hypophysectomy plus castration were similar to those of hypophysectomy alone. Administration of ACTH to hypophysectomized rats for 7 days did not reverse the effects of hypophysectomy on adrenal AR, nor did treatment with levothyroxine, dexamethasone, rat GH, or rat PRL. Treatment of hypophysectomized rats with 5alpha-dihydrotestosterone for 7 days caused a dramatic increase in the amount of detectable AR in both the ventral prostate and the adrenal gland, but had a trophic effect only in the ventral prostate. These findings suggest that the amount of immunoreactive AR detected in both the adrenal gland and the ventral prostate is enhanced by androgens: testicular androgens in the case of the ventral prostate and adrenal androgen in the case of the adrenal glands.  相似文献   

6.
Experiments have revealed that in treating rats for diabetes induced by alloxan, the Selaginella tamariscina complex injection given intraperitoneally (25g/kg) for 12 days helps lower the levels of blood sugar and serum lipid peroxide, as well as increase the concentration of serum insulin. Histologic observation has shown that this injection could repair the structure of pancreatic inlet B cells injured by alloxan.  相似文献   

7.
Development of alloxan diabetes was accompanied in dogs by regular changes in the phasic structure of the cardiac contractions. Direction of the changes in the indices of phasic analysis in the groups of dogs with an average (up to 144.3 +/- 12.5 mg%) and marked (up to 258.0 +/- 22.8 mg%) increase in the blood sugar level was the same, but their expression increased with the elevation of hyperglycemia. In marked hyperglycemia there was established an increase (in comparison with normal values) of the index of myocardial tension, a shortening of the period of ejection, a decrease of the mechanical coefficient and of the intrasystolic index, this coinciding with the character of changes of the corresponding indices in the patients suffering from diabetes mellitus, depending on the severity of the disease. The data obtained pointed to the significant influence of metabolic changes (assessed by hyperglycemia level) on the contractile function of the heart.  相似文献   

8.
Vitamin D3 intestinal transport and liver metabolism were studied in rats with alloxan-induced diabetes. The condition was induced by i.v. alloxan injection in a dose of 40 mg/kg b.m. Diabetes development was monitored by blood serum glucose measurements, carried out for 30 days. [3H]-cholecalciferol absorption in the rat intestine was found inhibited in the diabetic animals as against the reference animals, which fact results in disordered entry of vitamin D3 to the body. [3H]-cholecalciferol absorption by the liver is reduced in the examined condition, and the time of its metabolism is increased more than threefold as against the reference animals. The share of vitamin D3 hydroxylation by the liver of diabetic rats is also significantly reduced. The described disorders are responsible, among other things, for the reduction of the levels of vitamin D3 active metabolites in the blood serum of rats with experimental diabetes.  相似文献   

9.
We report a 30 years old woman with sporadic poliglandular autoimmune syndrome type II, first seen with an insulin-dependent diabetes mellitus and a Graves-Basedow disease that became spontaneously hypothyroid with positive antimicrosomal antibodies. Six years later she presented with persistent vomiting and a remarkable reduction in insulin requirements. She had low basal and stimulated-cortisol levels and the diagnosis of severe adrenal failure was reached. A CT scan showed normal adrenal glands, she did not have cutaneous hyperpigmentation nor evidences of mineralocorticoid deficit. A selective autoimmune damage of the fascicular zone was assumed but a selective damage of ACTH producing pituitary cells cannot be discarded. The importance of investigating adrenal function in cases of unexplained reduction of insulin requirements is emphasized.  相似文献   

10.
11.
We have demonstrated previously that spontaneously diabetic BB-Wistar rats exhibit decreased adrenal medullary catecholamine secretion in response to splanchnic nerve terminal stimulation. We hypothesized that this abnormality is caused by changes in the sensitivity of the adrenomedullary chromaffin cells to acetylcholine (ACh). To study this hypothesis, we isolated adrenal glands from control and spontaneously diabetic BB-Wistar rats, perfused them with ACh, and measured catecholamine secretion. Adrenal catecholamine release in response to ACh was significantly decreased at 2, 8, and 16 weeks after the onset of diabetes compared with age-matched, nondiabetic control rats. Catecholamine release in response to perfusion with 20 mM K+ was the same in adrenals from diabetic and control rats. The decreased responsiveness of diabetic rat adrenals to perfusion with ACh was significantly correlated with a decrease in the release of catecholamines in response to splanchnic nerve stimulation. A similar defect in catecholamine secretion was also seen in adrenals harvested from nondiabetic BB-Wistar rats following a 3-h period of acute hypoglycemia; however, the adrenal response to potassium was also decreased as was the catecholamine content of the adrenal. Conversely, nondiabetic BB-Wistar rats made diabetic with streptozocin (STZ) and maintained in a hyperglycemic state did not exhibit catecholamine hyposecretion 2 weeks after STZ administration. Collectively, the data describe decreased adrenomedullary response to cholinergic stimulation in spontaneously diabetic rats as early as 2 weeks after the onset of diabetes and that a similar, although more severe, hyposecretion occurs after acute, severe hypoglycemia.  相似文献   

12.
The studies reported herein were conducted to confirm that the pituitary gland is involved in maintaining growth hormone (GH) resistance in rats with insulin-dependent diabetes mellitus (IDDM) and to determine whether the adrenocorticotropic hormone (ACTH)-adrenal cortical axis is responsible. The rats were made diabetic by injecting streptozotocin (85 mg/kg body wt) IP once daily on two consecutive days. They were then injected with 15 IU insulin SC twice daily on two consecutive days to enable them to survive hypophysectomy or adrenalectomy. Intact nondiabetic (NonDb), diabetic (Db), hypophysectomized diabetic (HxDb), and adrenalectomized diabetic (AxDb) rats were injected twice daily with 50 micrograms porcine (p) GH or with 0.9% saline for 2 weeks following the surgeries. Serum glucose levels of the saline-injected Db, HxDb, and AxDb rats were significantly greater than those of the NonDb rats by 106%, 65% and 49%, respectively. However, the levels in the HxDb and AxDb animals were significantly lower than those of the Db group by 20% and 28%, respectively. Injections of pGH into NonDb rats increased serum glucose concentrations by 38%, over their saline-treated controls, and by 29% in AxDb rats. This diabetogenic effect of GH was not seen in any other group. Administration of pGH to Db rats failed to increase body weight gain, tall growth, tibial epiphysial plate width, or serum IGF-I concentration over saline-injected controls. By contrast, HxDb and AxDb rats injected with pGH showed significant increases in all four growth parameters. Total serum IGF-I concentrations in AxDb rats injected with pGH equaled those in NonDb controls. To determine whether the lack of corticosterone (B) in the AxDb rats was responsible for the reduced hyperglycemia and restored responsiveness to pGH, AxDb rats were given B in their drinking water at 5 or 25 micrograms/ml. Administration of B reduced the beneficial effects of adrenalectomy by restoring hyperglycemia and growth impairment, and partially restored resistance to the pGH injections. These studies confirm that the pituitary contributes to diabetic growth impairment and show that the ACTH-adrenal cortical axis is primarily responsible for the GH-resistant state that develops in rats with IDDM.  相似文献   

13.
We studied the difference in the susceptibility to neonatal streptozotocin (STZ) diabetes between spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Two-day-old female SHR and WKY were injected intraperitoneally with 75.0 mg/kg of STZ or vehicle for control. Hyperglycemia developed in both strains at 4 days of age, but SHR were more hyperglycemic. Overt hyperglycemia developed in SHR with aging after a partial recovery from initial hyperglycemia at 10 days of age, whereas WKY did not develop significant hyperglycemia except shortly after STZ treatment. Percentage of insulin-positive B cells in total islet cells and pancreatic immunoreactive insulin (IRI) content were measured at 4 days, 10 days, 4 weeks, and 12 weeks of age. B cells per islet and pancreatic IRI content were significantly reduced in STZ-treated groups as compared with control in both SHR and WKY at 4 days of age, but later they increased significantly with aging in both strains. However, the reduction in pancreatic IRI content relative to control was significantly greater in SHR than in WKY from 4 days (-94.5 +/- 3.5%, -84.1 +/- 4.8%; p < 0.01) to 12 weeks (-97.1 +/- 2.1%, -28.0 +/- 2.5%; p < 0.05), and the reduction in B cells per islet was also greater in SHR at 4 weeks of age. These results indicated that the initial destruction of pancreatic B cells induced by STZ was greater, and the following regeneration was less in SHR than in WKY. The association of the susceptibility to neonatal STZ diabetes with the development of genetic hypertension in SHR remained to be elucidated.  相似文献   

14.
One of the characteristics of obesity-associated diabetes is an elevated fasting plasma insulin concentration with a weak insulin secretory response to subsequent glucose stimulation. Evidence suggests that hyperglycemia and hyperlipidemia may contribute to the initiation and progression of this disordered islet glucose sensing. It has been proposed that reducing hyperglycemia and hyperlipidemia per se may improve islet glucose sensing. Here we studied glucose-dependent insulin release in islets isolated from ob/ob mice treated with dopamine agonists (bromocriptine and SKF38393, BC/SKF) which significantly reduced circulating glucose and lipid levels of ob/ob mice. Islets from BC/SKF-treated mice showed a marked decrease of the elevated basal insulin release to levels similar to lean mice. Such treatment also induced a higher secretory response to glucose stimulation compared with that in ob/ob mice with sustained hyperglycemia and hyperlipidemia. Similarly, when islets from untreated ob/ob mice were cultured for 7 days in 11 mM glucose in the absence of free fatty acid, the basal insulin release was significantly decreased and high glucose stimulated insulin release increased compared with that from islets cultured in medium containing 30 mM glucose and 2 mM oleate. The BC/SKF-induced reduction of elevated basal insulin release was associated with decreased hexokinase activity and basal cyclic AMP content in islet tissue. Our results demonstrate that dopamine agonist treatment improves basal insulin release in ob/ob mice and this effect may be mediated, in part, by a reduction of hyperglycemia and hyperlipidemia.  相似文献   

15.
The general aging sequence in tissues of healthy human beings is proposed to be: capillary endothelial cell damage --> arteriosclerosis --> decreased blood flow --> metabolic dysregulation --> secondary tissue damage. Molecular O2 is an obligatory substrate for the successive syntheses of 17alpha-OH pregnenolone and dehydroepiandrosterone (DHEA) by cytochrome P450c17 in the zona reticularis of the adrenal cortex, in which it is suggested that arteriosclerosis --> decreased blood flow --> O2 and glucose deficit --> decreased O2-requiring synthesis of DHEA --> eventual decrease in number of DHEA-synthesizing cells. Aging changes in the zona reticularis synergize with those in the hypothalamo-hypophyseal machinery that controls it neurally and hormonally, with ACTH-evoked pulsatile floods of cortisol coming from the adrenal zona fasciculata, with the onslaught of free radicals generated by the metabolism of catecholamines released from interdigitating cells of the adrenal medulla, and with age-correlated disabilities of erythrocytes to bind and release O2 to decrease the viability of the DHEA and dehydroepiandrosterone sulfate (DHEAS)-forming cells. One of the chief functions of serum DHEAS in the male may be to act as an allosteric facilitator of the binding of testosterone (T) to serum albumin, thereby helping target T to specific receptors and to allosteric sites for rapid and efficient action at the cellular level. There is reason to consider combining O2 therapy with appropriate administration of DHEA and T to optimize steroid functionality in the healthy aging male, and thus, possibly, to alleviate some of the age-related cognitive and physical decrements that occur.  相似文献   

16.
A model of acute carbon monoxide poisoning combined with spreading depression (SD) induced metabolic stress was used to examine the protective effects of cerebrolysin (CL) on the development of electrophysiological, behavioral and morphological signs of hypoxic damage. Capillary electrodes were implanted into the neocortex and hippocampus of anesthetized rats which were then exposed for 90 min to breathing of 0.8% to 0.5% CO, while 3 to 4 waves of cortical and hippocampal SD were elicited by microinjections of 5% KCl. Duration of SD-provoked depolarization of cerebral cortex and hippocampus was noted. Nine and 18 to 19 days later propagation of SD waves was recorded with the same electrodes and decrease of their amplitude was used as an index of brain damage which was significant in the hippocampus but not in the cortex. CL-treatment (2.5 ml/kg per day) started after CO administration and continued for 14 days significantly improved hippocampal recovery manifested by increased amplitude of SD waves. Behavioral tests performed 10 and 20 days after CO poisoning in the Morris water maze revealed better performance (escape latency 7 s) in the CL-treated than in untreated animals (14 s). Morphological analysis showed marked damage in the hippocampus consonant with electrophysiological and behavioral findings in the same animals. No apparent histological damage was found in rats exposed to CO inhalation alone without the additional SD-provoked depolarization. It is concluded that chronic CL-treatment enhances recovery of hippocampal tissue after hypoxic damage of intermediate severity.  相似文献   

17.
RATIONALE AND OBJECTIVES: The pathogenesis of brain injury following radiosurgery is poorly understood. To better elucidate the relationship between blood-brain barrier disruption and metabolic derangements, we used magnetic resonance (MR) imaging and 1H MR spectroscopy to detect early changes from focused single-fraction, high-dose irradiation injury in rat brains. METHODS: Using the Leksell gamma knife, we irradiated the frontoparietal cortex of 11 male Wistar rats with a single dose of 120 Gy. Four weeks later, we sequentially performed water-suppressed 1H MR spectroscopy and gadopentetate dimeglumine-enhanced T1-weighted MR imaging. Metabolic maps were created of n-acetylaspartate (NAA), creatine and choline (Cr/Cho), and lactate from the MR spectroscopy data set. Detection of irradiation injury among the tested modalities was assessed by receiver operating characteristic analysis and by quantitative signal intensity changes. Pathologic confirmation of irradiation damage was obtained in all rats. RESULTS: Gadopentetate dimeglumine-enhanced T1-weighted MR imaging was the only imaging modality that detected statistically significant signal intensity changes (p < .05). No reproducible changes in the metabolites of interest could be detected by 1H MR spectroscopy. CONCLUSION: In our animal model, blood-brain barrier disruption was a reproducible, integral finding of single-fraction, high-dose irradiation injury. No reproducible metabolic derangements of ischemia or necrosis were detected by 1H MR spectroscopy, possibly because of dose-latency effects or sensitivity issues.  相似文献   

18.
It was taken 32 male Wistar rats, weighting between 130 g and 150 g, free feeding, to study the total and specific activities of lactase, invertase and maltase of small intestine of rats. The animals were divided by chance in 3 experimental and 1 control group. 1. group--Aloxanic diabetes rats: treated with 1 unit of NPH insulin every day: after the 4th day of aloxane administration, all rats were killed. 2. group--Aloxanic diabetes rats--treated for 5 days with 1 unit of NPH insulin every day; after the 5th day until the 7th they were treated with 4 units of NPH insulin and were also killed. 3. group--Hyperinsulinism rats--Normal rats were treated for 4 days with 4 units of NPH insulin every day. After the 5th day they were killed. 4. group--Control group--Normal rats, free feeding. They were observed during 4 days and were also killed. The results showed that none difference was observed in the 4 groups of rats about the total and specific activities of lactase, invertase and maltase of the small intestine. In this study, all the animals with aloxanic diabetes were treated with insulin. Then, it is possible that the insulin inhibited the stimulator effect of the diabetes upon the dissacaridases of the small intestine of the rats.  相似文献   

19.
Fifty-nine patients with chronic pancreatitis were studied in retrospect. The incidence of overt diabetes was high, 36/59. Half of the diabetics were insulin-dependent, and among these labile diabetes with hyperglycemia and high amounts of glucose in the urine was not uncommon. Hypoglycemic episodes were noted in 14 of the 18 insulin-treated patients, and in 3 patients severe hypoglycemia was believed to be the cause of death. Mechanisms leading to such disastrous hypoglycemia are discussed, and a hypothesis regarding lack of glucagon as the cause of severe hypoglycemic attacks was experimentally tested by measuring pancreatic glucagon in plasma in two patients with pancreatic diabetes and severe brain damage following hypoglycemic coma. Low basal glucagon values were found, and the normal rise upon insulin-induced hypoglycemia was not seen. From these results it may be justified to suggest, firstly that glucagon should be used in the management of severe hypoglycemia in chronic pancreatitis, and secondly that a certain degree of hyperglycemia should be allowed in the treatment of diabetes in these patients.  相似文献   

20.
The purpose of the present study was to investigate the influence of nutrients and insulin on IGFs and their binding proteins (IGFBPs) during the fetal and neonatal periods of three rat populations: (a) rats undernourished by a 35% reduction in the diet from day 16 of gestation, (b) streptozotocin-induced diabetic rats from the same day, or 4 days after birth, and (c) control rats. Fetuses from the diabetic population showed a decrease in insulinemia at 19 and 21 days, along with an increase in glycemia at all stages. Neither glycemia nor insulinemia changed in the fetuses of undernourished mothers, but body weight was decreased at birth. Serum IGF-II decreased at 18 and 19 days of gestation in fetuses from undernourished mother, and increased at 18, 19 and 21 days in fetuses from diabetic mothers. Serum IGFBPs of low molecular weight (IGFBP-1 and IGFBP-2) increased in the three fetal populations studied, although no changes in serum IGFBPs were found from the effect of undernutrition or diabetes, but fetal liver IGFBP-1 mRNA expression was found to decreased in undernourished and diabetic animals as compared with controls. In neonatal rats, body weight, insulinemia and serum GH decreased in both undernourished and diabetic rats vs controls, while glycemia decreased in the undernourished and increased in the diabetic group. Serum IGF-II decreased only in diabetic rats and serum IGF-I decreased in both groups. The neonatal serum 30 kDa complex (IGFBP-1 and -2) also increased in undernutrition and diabetes parallel to the expression of mRNA. But, taken together, the changes in IGFBP peptide levels and liver mRNA expression strongly suggest that the 30 kDa complex seems to be composed mostly of IGFBP-1 in the diabetic group and of both IGFBP-1 and -2 in the undernourished animals. The studies of liver mRNA expression of IGFs and IGFBPs confirm the different metabolic control mechanism for the availability of IGFs by the IGFBPs, depending on the animal's maturity. The different adaptation shown by the diabetic neonatal population was confirmed by correlation studies between body weight, glycemia, insulinemia, IGF-I and IGFBPs. The different mechanism of adaptation in diabetic vs undernourished rats seems to be probably due to the decisive role played by hyperglycemia in the diabetic population, and also shows the crucial influence of nutritional status on IGFs and IGFBPs.  相似文献   

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