Metabolic characteristics of renal insulin uptake.
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Animals↗
Biomedical subjects
R Rabkin
Publications and source records attributed to R Rabkin.
Removal of immunoreactive arginine vasopressin by the perfused rat liver.
To assess the ability of the liver to remove immunoreactive arginine vasopressin (AVP) from the circulation and to determine the effect of certain metabolic factors on the process, a study was carried out with rat livers perfused at 37 C with an oxygenated albumin--electrolyte solution containing AVP (117 +/- 4.5 muU/ml). In controls, the hepatic clearance of AVP was 795 +/- 120 microliter/min (SEM). The addition of AVP in concentrations up to 9029 microU/ml, perfusion with a glucose-free medium, or perfusion without oxygen did not significantly alter the hepatic clearance of AVP. However, perfusion with cold medium (11 C) significantly altered AVP removal in that initially AVP removal increased, while later on AVP removal became completely inhibited. This phenomenon may possibly be a consequence of a cold-induced increase in hepatic AVP trapping which is rapidly saturated due to a cold-induced depression of AVP transport and degradation. Support for this thesis was provided by finding that high AVP concentrations depressed the cold-endhancing removal phase.
Animals↗
Large group influence for decreased drug use: findings from two contemporary religious sects.
This paper reports on studies designed to clarify the role of large cohesive groups in effecting diminished drug use among their members. Subjects were drawn from two contemporary religious sects and data were obtained by administering self-report questionnaires under controlled conditions, in cooperation with the sects' leadership. Data which bear directly on changes in drug use are reported here. Members of the Divine Light Mission (DLM), many of whom had been involved in the "counterculture" of the early 1970s, reported incidence of drug use prior to joining which was much above that of a nonmember comparison group. Reported levels were considerably lower after joining, and the decline was maintained over an average membership of 2 years. Unification Church (UC) members showed a similar pattern but their drug use began at a somewhat lower level and declined further still; this reflects a stricter stance toward illicit intoxicants in the UC, and relatively less openness to transcendental altered consciousness, which is an integral part of DLM meditation. Data from persons registered for UC recruitment workshops corroborated retrospective reports of the long-standing members. Changes in the consumption of tranquilizers were also considered. Data on caffeine consumption reflected less strict commitment to controls over this agent. The decline in drug use was considered in relation to feelings of social cohesiveness toward fellow group members, which was a significant predictor of change in drug use in multiple regression analysis. The findings are examined in relation to the interplay between behavioral norms in a close-knit subculture and the role of its beliefs and values in determining levels of drug use.
Adult↗
Effect of prolonged uremia on insulin metabolism by isolated liver and muscle.
As the prolonged metabolic clearance rate of insulin in chronic uremia cannot be entirely explained by impaired removal and degradation of insulin by the kidney, we set out to determine whether prolonged uremia depresses other major sites of insulin degradation. The study was conducted with livers and skeletal muscle obtained from normal control rats and uremic rats 4 weeks after 80% nephrectomy. Despite a significant difference between renal function in the control and uremic rats (BUN, 18 vs. 46 mg/dl), there was no significant difference in the clearance of insulin by isolated uremic or control livers perfused with a bloodless medium. Similarly, the 125I-insulin degrading activity of liver homogenates was not depressed by uremia. In contrast, binding and degradation by uremic liver cell membranes was significantly reduced to 58% and 85% of the controls, respectively. Degradation by homogenates of skeletal muscle and by intact epitrochlaris muscle was significantly less in uremics than in controls. These results indicate that chronic uremia depresses skeletal muscle insulin degradation but not hepatic insulin removal or degradation despite a decrease in insulin binding and degradation by liver plasma membranes. It thus appears that depression of insulin degradation by muscle may contribute to the prolonged insulin metabolic clearance rate seen in chronic uremia. Furthermore, it is possible that the impaired binding of insulin to liver membranes may play a role in the insulin resistance of uremia.
Animals↗
The handling of immunoreactive vasopressin by the isolated perfused rat kidney.
Using the isolated rat kidney perfused with an artificial medium containing glucose as the sole fuel, we studied the renal handling of immunoreactive arginine vasopressin (AVP) and determined the effect of various factors on the ability of the kidney to remove AVP. In control kidneys perfused with AVP at concentrations below 116 muU/ml, the organ clearance of AVP (OC(AVP)) was 1,145+/-47 (SE) mul/min, whereas glomerular filtration rate (GFR) averaged 515+/-37 mul/min. Filtration could thus account for up to 45% of the OC(AVP), the balance presumably being cleared from the peritubular circulation. Of the AVP filtered, only 38% could be recovered in the urine (urinary clearance AVP averaged 205+/-12 mul/min) suggesting that the balance was taken up by the tubular epithelium and degraded. Fractional excretion of filtered AVP rose significantly in the presence of anoxia and cold (10 degrees C) to 49 and 59%, respectively, but was not affected by ouabain or high levels of AVP (458+/-58 muU/ml). The OC(AVP) was not significantly altered by the absence of glucose in the perfusate, anoxia, or ureteral ligation, maneuvers that were associated with significant reductions in GFR. In these and the control experiments, there was a significant inverse correlation between GFR and peritubular clearance emphasizing the importance of the latter (r = -0.749; P < 0.001). Cold, ouabain, and high concentrations of AVP reduced the clearance of AVP by the kidneys. On the basis of these studies we conclude that the kidney clears AVP from the circulation via two pathways, glomerular clearance and peritubular clearance. This exposes both the luminal and contraluminal surfaces of the tubular cells to the hormone, allowing these cells to remove AVP from the filtrate and the peritubular compartment. Noteworthy is the observation that under several conditions when GFR falls reducing the glomerular clearance of AVP, peritubular clearance increases and the total clearance of AVP by the kidney remains constant.
Albumins↗
The "Moonies": a psychological study of conversion and membership in a contemporary religious sect.
The authors undertook this study to enhance psychiatric understanding of contemporary charismatic religious sects. After a pilot study, a representative sample of members of the Unification Church (N = 237) completed a 216-item structured questionnaire. Respondents were below the mean for an age- and sex-matched group on a psychological general well-being scale, and they reported significantly greater neurotic distress before conversion. The authors discuss correlates of an improved emotional state following conversion and employ attribution theory, drawn from social psychology, to put the conversion process into a psychiatric perspective.
Adult↗
Effect of renal transplantation on pituitary gonadal function.
Twelve adult male patients who had undergone successful renal transplantation were investigated. The gonadotropin responses to 100 microgram luteinizing hormone-releasing hormone (LRH) were studied, and basal serum testosterone and prolactin assayed. Significantly elevated mean basal levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were found, associated with a correspondingly excessive LH and FSH response to LRH. Mean basal serum testosterone levels in the posttransplant patients were significantly lower than in normal controls, while the mean basal prolactin levels were similar in the two groups. The results were not influenced by the varying degrees of renal function found in the posttransplant patients.
Adult↗
Factors influencing the handling of insulin by the isolated rat kidney.
The renal handling of immunoreactive insulin was studied in the isolated perfused normothermic rat kidney to determine (a) the relative contributions of glomerular clearance and peritubular clearance to the renal clearance of insulin under different conditions, (b) what metabolic factors influence the ability of tubular cells to remove insulin from the glomerular filtrate and the peritubular circulation, and (c) whether the same factors influence the luminal and contraluminal uptake of insulin.In control kidneys the organ clearance of insulin (OCi) was 974+/-63 mul/min (SEM), of which a maximum of 46% could theoretically be accounted for by filtration. OCi was not altered by fasting, lack of exogenous fuel (glucose), or the addition of cyanide. The glomerular filtration rate did not correlate with the OCi, but there was a significant (P < 0.001) negative correlation (r = -0.828) between the peritubular clearance and glomerular filtration rate. Both N-ethylmaleimide and cold (10 degrees C) reduced the rate of insulin removal. Fractional excretion of filtered insulin (9.7+/-1.7% in controls) was not significantly altered by fasting or perfusing without glucose. In contrast, KCN increased fractional excretion of insulin to 41.9+/-3.7% whereas cold increased fractional excretion to 69.0+/-3.3%. This study indicates that renal tubular cells remove insulin from the tubular lumen and the peritubular compartment. Furthermore, the data suggest that insulin removal by tubular cells is a temperature-sensitive process consisting of two different systems. The system associated with the luminal aspect of the cell appears to be dependent on oxidative metabolism, whereas the system associated with the contraluminal aspects of the cell appears to be independent thereof. Under several circumstances when the glomerular clearance of insulin falls thereby reducing the amount of insulin absorbed by the luminal aspect of the cell, contraluminal uptake increases, and a constant rate of insulin removal is maintained by the kidney.
Animals↗
The handling of insulin, proinsulin, and C-peptide by the isolated rat kidney.
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Animals↗
Insulin extraction from the renal peritubular circulation in the chicken.
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Animals↗
Hyperlipidaemia in renal transplant patients.
The prevalence, nature and possible aetiology of post-transplantation hyperlipidaemia were studied in 94 renal allograft recipients. Sixty-five per cent of the group had hypercholesterolaemia or hypertriglyceridaemia, and types IIb and IV were the commonest forms of hyperlipoproteinaemia encountered. The pathogenesis of post-transplantation hyperlipidaemia is complex. Hypertriglyceridaemia was maximal in the first year after transplantation and could be correlated with high corticosteroid dosage during this period. Thereafter hypertriglyceridaemia was less marked and was related to obesity, corbohydrate intolerance and basal insulin levels. Mean cholesterol levels were elevated throughout the post-transplantation period, varied little and could not be related to corticosteroid dosage, body weight, carbohydrate intolerance, basal insulin levels or renal dysfunction.
Adolescent↗
Kaposi's sarcoma in an immunosuppressed renal allograft recipient.
A 47-year-old White man developed a buccal Kaposi's sarcoma 15 months after receiving a renal allograft. Atypical clinical and histological features were noted. A previous viral infection might have played a role in the occurrence of this patient's tumour but other possibilities of tumour induction in the immunosuppressed host are discussed. Although the condition is lethal when diagnosed after renal transplantation, this case report demonstrates that prompt diagnosis and radiotherapy may result in permanent cure.
Adult↗
Strongyloides stercoralis hyperinfection in a renal allograft recipient.
A patient who had received a renal allograft required intensive immunosuppression for a severe rejection episode. Four months after the graft he died of septicaemia and respiratory failure caused indirectly by a Strongyloides stercoralis hyperinfection. Patients from endemic areas who are to undergo a renal transplant should be screened for the parasite before receiving immunosuppressive therapy. Should this infection occur after transplantation, early diagnosis and treatment with thiabendazole is essential to prevent the high mortality rate associated with Strongyloides hyperinfection.
Adult↗
The effect of different preparations of human growth hormone on plasma renin activity in normal males.
The effect of acute administration of 2 preparations of growth hormone (hGH) on plasma renin activity (PRA) was studied in normal volunteers. 4 IU of standard, commercially available hGH II, Kabi, Sweden) were injected im into each of four normal subjects, and the PRA was determined in the basal state and at 30, 60, 120, 180, and 240 min after injection. Free fatty acid (FFA) was determined basally and at 15 and 210 min post-injection. The study was repeated on a different day in the same group using highly purified hGH (hGH I, 4 IU) virtually free of arginine-vasopressin. Four other normal subjects received 12 IU standard hGH (hGH II, Kabi, Sweden). There was no significant difference in PRA values with 4 IU of either preparation or with 12 IU of hGH II in any of the groups, although mean PRA was elevated in two of the patients receiving 12 IU hGH II. A rise in FFA occurred in all subjects, indicating the biological activity of hGH preparations. The possible significance of these findings to the renin-angiotensin system found in acromegaly is considered.
Acromegaly↗
Behavior modification. Present status in psychiatry.
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Behavior Control↗
Post-transplantation analgesic dependence in patients who formerly suffered from analgesic neophropathy.
Twenty-two patients with functioning grafts who originally developed renal failure due to analgesic nephropathy ("analgesic" group), and 84 patients with various other causes of renal failure ("non-analgesic" group) were studied over one year to assess the extent of analgesic use and abuse. On each occasion that one of these patients reported to hospital a urine sample was collected and analyzed for N-acetylparaminophenol (NAPA). Of the "analgesic" group of patients, 14% had consistently negative urine samples while 41% showed NAPA in more than half the urines collected. In the "non-analgesic" group 29% of patients had entirely negative urine tests, and in only 7% were more than half of the urines NAPA-positive. Patients in the "non-analgesic" group readily admitted taking anaglesics at frequencies compatible with the observed number of positive tests. This contrasted with the "analgesic" group in which 14 of 19 patients with NAPA-positive urines denied analgesic intake. This is considered to be a guilt manifestation in patients who have developed a psychological dependence on analgesics and have recidivated with full knowledge of the possible harm these drugs may inflict on their grafts.
Analgesics↗
Polymorphonuclear leucocyte function in chronic renal failure and after renal transplantation.
Neutrophil chemotaxis, phagocytosis and bactericidal ability were assessed in patients with chronic renal failure on conservative therapy, in others on regular peritoneal and haemodialysis, and in a group of patients who had received renal allografts. Chemotaxis was abnormal in all groups. The groups on peritoneal and haemodialysis had mildly impaired phagocytosis, while killing ability was normal in all but the group on conservative therapy who showed a mild defect. Serum from groups when activated with endotoxin was poorly chemotactic to normal neutrophils, but functioned normally as opsonins for phagocytosis.
Blood Bactericidal Activity↗