Small Doses Of Insulin Research Articles

Conditioning insulin effects.

It has previously been demonstrated that after a number of insulin injections in rats, an injection of a placebo leads to an elevation in blood sugar. It has been suggested that this apparent conditioned compensatory response is an artifact resulting from stressing the subject (when large doses of insulin are used) or represents a nonassociative phenomenon (when small doses of insulin are used). These two suggestions were rejected on the basis of the results of Experiments 1 and 2, respectively. Experiments 3 and 4 demonstrated that although the behavioral effects of insulin can be conditioned to the injection procedure, such conditioned insulinlike behaviors (contrary to suggestions of many investigators) are not mediated by a pypoglycemic state.

Endocrine responses to insulin hypoglycaemia in the young calf.

1. Variations in the output of glucocorticoids and catecholamines from the right adrenal gland, in response to insulin hypoglycaemia, have been investigated in calves 2-5 weeks after birth. These have been correlated with changes in the concentration of glucocorticoids and glucagon in arterial plasma. 2. Moderate hypoglycaemia for a limited period (0-1 u. insulin/kg), elicited a prompt increase in steroid output from the adrenal gland followed by a significant rise in plasma glucagon concentration. By comparison, changes in both catecholamine output and peripheral plasma glucocorticoid concentrations were found to be trivial in this group of animals. 3. Administration of a larger dose of insulin (0-5 u./kg) produced a more substantial fall in plasma glucose concentration followed by spontaneous recovery within 2-3 hr. This stimulus elicited the release of greater amounts of both cortisol and corticosterone, followed by a significant increase both in the output of adrenaline and in plasma glucagon concentration. Increase in steroid output was accompanied by an increase in adrenal blood flow and was associated with elevated concentrations of both steroids in arterial plasma. 4. The adrenal cortical response and associated changes in plasma steroid concentration were found to be transient even in response to persistent and intense hypoglycaemia (4 u. insulin/kg). The increase in plasma glucagon concentration in this group of animals was not significantly greater than that produced by smaller doses of insulin. However, substantial amounts of adrenaline (78 plus or minus 14 ng. kg-minus 1 min-minus 1; maximum; n equals 9) together with a little noradrenaline (10 plus or minus 3 ng.kg-minus 1 min-minus 1; maximum; n equals 9) were released from the right adrenal gland under these conditions. 5. Changes in adrenal blood flow could be related to adrenal glucocorticoid output in calves given 0-1 or 0-5 u. insulin/kg. In animals given the largest dose of insulin adrenal blood flow was found to increase coincidentally with rising steroid output but this hyperaemia then persisted after steroid output had subsided to values within the normal range. 6. Calves given the largest dose of insulin (4-0 u./kg) invariably collapsed and convulsed after 2-3 hr, but these symptoms could not be related to any particular endocrine response. No clinical signs of hypoglycaemia were observed in the other animals. 7. The results are discussed in relation to previous studies of adrenal function in this and other species.

Fat cells in ontogenesis.

In recent years it was revealed that in adipose tissue active cell proliferation and an increase of cell number takes place; this process participates in a significant way in the increase of adipose tissue mass during ontogenetic development (1–4). The growth of adipose tissue by hyperplasia of adipocytes can be stimulated in growing animals by some nutritional stimuli, which include refeeding, after previous fasting (5) or hyperphagia in the early postnatal period (6,7). In recent years we studied intensely this induced hyperplasiaof adipose tissue and found that in the mechanism of triggering of DNA synthesis insulin may play a role, similar to the role it plays in some other tissues (8–11). We have demonstrated that the administration of small doses of insulin for 24–72 hr leads to an increase of DNA content of adipose tissue. After isolation of cellular and subcellular fractions fron adipose tissue we found that insulin stimulated the synthesis of nuclear and not of nitochondrial DNA and caused increased proliferation of fat and stromavascular cells. In keeping with this was also the increase in the number of fat and stromavascular cells ascertained by calculation and histological examination of tissue, when cells in mitotic division were found as well as an increased ratio of smaller adipocytes (12–14).

Continuous intravenous infusion of small doses of insulin in treatment of diabetic ketoacidosis.

Continuous intravenous infusion of small amounts of insulin has been used in the management of a series of patients with diabetic ketoacidosis. In 13 patients with a plasma glucose level on admission of 725 mg/100 ml (+/- 80 S.E. of mean) and an arterial pH of 7.07 +/- 0.05 a mean loading dose of 6.5 +/- 0.82 units of soluble insulin was administered intravenously, and thereafter a sustaining infusion of 6.5 +/- 0.82 U/hr was continued until ketosis was corrected and the plasma glucose fell below 300 mg/100 ml. The total insulin dose needed to achieve this was 39.2 +/- 6.6 units given over a 3 to 10-hour period. Plasma insulin was measured in patients who had not previously received insulin and the mean level at an infusion rate of 4 U/hr was 75.6 +/- 8.0 muU/ml. Plasma glucose fell at a regular rate of 101 +/- 11 mg/100 ml/hr, and ketosis improved in parallel. Plasma potassium was well maintained throughout treatment. This regimen of treatment was clinically effective and simple to follow.

Effect of small doses of insulin in vivo on the proliferation and cellularity of adipose tissue.

The effect of insulin in vivo on the proliferation and cellularity of epididymal adipose tissue of growing rats was investigated. Following the intraperitoneal administration of small amounts of insulin (500 μU/ rat, twice a day), which did not influence the blood sugar level and food intake, it was found that repeated administration of insulin for 48–72 h leads in adipose tissue to an enhanced incorporation of 14C-2-thymidine into DNA and to an increase of the total amount of DNA and RNA in the fat body. The enhanced DNA synthesis in adipose tissue of insulin-treated rats was marked in nuclear DNA and absent in mitochondrial DNA. After fractionation of adipose tissue by collagenase an enhanced DNA synthesis was found in the fraction of adipose and stromavascular cells. Morphological examination of adipose tissue of insulin-treated rats revealed cells in the phase of mitotic division and an increased ratio of fat cells of smaller size. Calculation of the number of cells in the epididymal fat body revealed that, after administration of insulin, the number of adipose and stromavascular cells increased.

The role of the autonomic innervation in the control of glucagon release during hypoglycaemia in the calf.

1. The extent to which the autonomic innervation to the pancreas is implicated in the control of glucagon release during hypoglycaemia has been investigated in calves 3-6 weeks after birth.2. A pronounced rise in plasma glucagon concentration occurred in normal conscious calves in response to hypoglycaemia following administration of insulin (0.1 u./kg). Prior treatment with atropine caused no significant change in the hypoglycaemic response to insulin in these animals but the rise in plasma glucagon concentration was delayed.3. Section of both splanchnic nerves produced no significant change in the tolerance of conscious calves to this small dose of insulin and the changes in plasma glucagon concentration in these animals were within the normal range.4. In contrast, the same dose of insulin produced severe hypoglycaemia, accompanied by convulsions, in atropinized calves with cut splanchnic nerves. In spite of the intensity of the hypoglycaemic stimulus the rise in plasma glucagon concentration was both delayed and diminished in these animals.5. Administration of atropine alone (0.2 mg/kg) to normal fasting calves produced a significant fall in the mean plasma concentrations of both glucose and glucagon (P < 0.01) within 30 min, without affecting that of insulin.6. A significant increase in plasma glucagon concentration also occurred in response to stimulation of the peripheral ends of the thoracic vagi in adrenalectomized calves with cut splanchnic nerves under barbiturate anaesthesia. A rise in mean plasma glucose concentration was also observed in these experiments and found to be significantly correlated with the glucagon response.7. It is concluded that changes in either sympathetic or parasympathetic efferent activity may modify plasma glucagon concentration in the conscious calf, but that only the latter mechanism is likely to be implicated in the response to changes in plasma glucose concentration within the physiological range.

Effect of exogenous bonito insulin on endogenous insulin secretion in dogs.

The secretion of endogenous insulin was investigated through the effect of the infused exogenous bonito insulin on dogs. The systemic infusion of small doses of exogenous bonito insulin (0.3mu/kg) which proved inert on the blood sugar levels, resulted in an inhibition of endogenous insulin secretion. The prolonged infusion of exogenous bonito insulin inhibited both the basal insulin secretion and the biphasic pattern in glucose-induced insulin release. The mean level of endogenous insulin in the pancreatic vein decreased significantly (p<0.05) from 453±97μU/ml (immediately before the sustained infusion of exogenous bonito insulin) to 184±63μU/ml four hours after the start of the infusion. The calculated endogenous insulin output in the group treated with exogenous insulin also decreased significantly (p<0.05).The two phases of glucose-induced insulin secretions in the insulin treated subjects were less marked than those in the control group (p<0.05), and occurred much more rapidly than those in the control.These results suggest that the insulin secretion from the pancreas is affected by the prolonged infusion of exogenous bonito insulin.

SMALL DOSES OF INTRAMUSCULAR INSULIN IN THE TREATMENT OF DIABETIC " COMA "

A new regimen is described for the treatment of diabetic " coma " using small intramuscular doses of insulin. In fourteen patients admitted with plasma-glucose and blood-ketone-body concentrations of 637 ± 60 S.E.M. mg. per 100 ml. and 12·1 ± 1·2 mM, respectively, a mean initial dose of 16 + 2 S.E.M. units insulin was given with hourly doses of 5 to 10 units thereafter. Cumulative insulin therapy amounted to 43 ± 4, 59 ± 5, and 98 ± 6 units at 6, 12, and 24 hours. Mean serum-insulin in patients who had not previously had insulin therapy was 33 ± 10 S.E.M. μU per ml. 1 hour after the first dose, rising to 93 ± 14 μU per ml. at 5 hours. Plasma-glucose, plasma-free-fatty-acids, and blood-glycerol all fell significantly within the first hour of treatment. Plasma-glucose fell at a regular rate of 90 mg. per 100 ml. per hour. The rate of fall was not influenced by blood-ketone-body concentration or previous insulin treatment, but it was significantly reduced by infection. The new regimen was simple to follow, clinically effective, and had advantages over conventional therapy with regard to changes in plasmapotassium, blood-lactate, and plasma-growth-hormone.

Growth hormone secretion in diabetic retinopathy

The plasma HGH response to insulin-induced hypoglycemia (0.2 U/kg) and the 24-h plasma HGH pattern during a normal day have been studied in 14 non obese long-term insulin-dependent diabetics with proliferative retinopathy, mean age 39 ± 2 (ranging between 24 and 50 years). Plasma glucose and FFA were also determined. The results were compared with those of 18 normal subjects of similar age and weight. The mean plasma HGH response to insulin in retinopathic diabetics was slightly lower (with no significant differences) than in controls in whom hypoglycemia was induced with a smaller dose of insulin (0.1 U/kg). This pattern of plasma HGH could be related to the delayed plasma glucose fall observed in retinopathic diabetics in comparison to normal subjects, even if the HGH peak after insulin in both groups (18.61 ± 4.32 ng/ml in retinopathic diabetics, 27.43 ± 4.19 in controls) did not seem to be correlated to the degree of hypoglycemia, but rather to the age of the subjects. Plasma HGH pattern, studied with blood samples taken every three hrs during a normal day, did not reveal differences between the diabetics and controls. Plasma glucose, however, was higher in retinopathic diabetics than in controls in spite of the insulin treatment. These results show that in diabetic patients with retinopathy, increased HGH secretion does not occur in conditions of ordinary life or after insulin-induced hypoglycemia, although the HGH plasma levels observed in retinopathic diabetics could be considered too high in relation to the elevated blood glucose levels.

Intravenous Insulin: Effect of Binding to the Infusion Set Upon the Dose Administered

Insulin has been known for many years to adsorb to laboratory glassware. This binding is thought to be a nonspecific surface phenomenon which also occurs when small doses of insulin are administered by slow intravenous infusion for therapeutic purposes. While only 8% of the administered insulin is adsorbed to the glass infusion bottle over two hours if 10 units of insulin is added to 500 ml of isotonic saline, when one includes the insulin adsorbed to the tubing, 30% of the insulin activity is lost in two hours.

Insulin fixation and glucose uptake by forearm tissues in response to infusions of physiological amounts of insulin in non-diabetic subjects.

Insulin fixation and glucose uptake have been studied in the forearm tissues of nine lean non-diabetic men for three consecutive hours, during a fasting state, an intra-arterial infusion of a small dose of insulin (25–100 mU) and a recovery period. When insulin was administered, the arterial plasma immuno-reactive insulin rose to levels ranging from 15 to 65 μU/ml; the tissue insulin fixation was significantly increased during this period, but no effect on tissue glucose uptake was observed. A close correlation was found between the arterial plasma insulin concentration and the tissue insulin fixation. — The injection of 200 mg glucose intraarterially at the end of the study resulted in a reversal of the arterio-venous gradient of plasma insulin concentration. — The results show that large amounts of circulating insulin can be bound to the forearm tissues without exerting an effect on glucose uptake. It is suggested that the binding of insulin occurs at the vascular endothelium and that it is reversible by increased concentrations of blood glucose.

Insulin allergy and insulin resistance: Case report with immunologic studies

This case report describes the course of a woman with adult-onset diabetes who received insulin therapy a second time. Shortly thereafter she developed generalized allergic reactions to insulin followed by a period of insulin resistance during which allergic reactions were no longer present. Insulin therapy was stopped, and 7 months later small doses of insulin resulted in generalized urticaria and angioedema. Antibodies to bovine insulin of the IgG, IgA, IgM, and IgE classes and Prausnitz-Küstner antibody activity to bovine insulin were observed in this patient. The findings support the concept of IgE antibody being responsible for the allergic manifestations and IgG antibody producing a protective or “blocking antibody” effect.

Insulin response in pancreatectomized dogs treated with oxytetracycline.

Treatment with dxytetracycline seems to prolong and intensify the activity of insulin administered to pancreatectomized dogs. Oxytetracycline-treated dogs can be kept normoglycemic with small doses of insulin, have nondiabetic glucose tolerance, and exhibit the impaired hyperglycemic and cardiac responses to epinephrine of normal animals treated with insulin.

Nine years' experience with tolbutamide in the treatment of diabetes

Experience with tolbutamide in the treatment of 3,387 selected patients for periods up to 9 years has been presented. These included 526 with “primary” failures and 202 with “indeterminate” failures; 104 other patients received tolbutamide in combination with other hypoglycemic agents. The remaining 2,555 patients achieved satisfactory (good or fair) control for at least 1 month. Of these, 2,056 had continuously satisfactory control throughout the period of observation, whereas secondary failures occurred in 499 patients at an average rate of 25 per cent/year. Men had fewer secondary failures than women. A significantly larger proportion of persons with satisfactory control had a duration of known diabetes of under 1 year as compared to those with primary or secondary failures. The age at onset of diabetes of 60 years and over was significantly more frequent among those with continuously satisfactory control than in the groups with primary or secondary failures. A total of 1,266 patients had been treated with insulin prior to tolbutamide therapy. The proportion of those with continuously satisfactory response on tolbutamide who had received small insulin doses prior to the oral therapy was significantly greater than in those with primary or secondary failures. Continuously satisfactory control with tolbutamide was attained more often among the patients whose diabetes had been controlled satisfactorily also with insulin. Forty-eight per cent of the patients who returned to insulin after a variable period of tolbutamide therapy, showed a higher insulin requirement than before the oral therapy. No other significant differences were found between those patients with continuously satisfactory control and those with secondary failure in this selected population. Four hundred thirty patients had received tolbutamide for 6 to 9 years. The secondary failures in this group amounted to 113 (26 per cent). In this highly selected population, no differences were discernible that would help predict those likely to have a long-term satisfactory control with tolbutimide. The overall attrition rate of patients treated with tolbutamide was high. Only about 10 per cent of patients started on tolbutamide were known to be taking the drug 6 to 9 years later. Reduction in numbers was due chiefly to death (not related to tolbutamide administration), secondary failure, or loss to follow-up. Side effects to tolbutamide were remarkably few and benign. Three patients developed blood dyscrasia (one each with thrombocytopenic purpura, nonthrombocytopenic purpura and neutropenia) documented by tests for circulating antibodies, and in each instance discontinuance of the drug resulted in recovery.

Non-suppressible insulin-like activity of human serum: II. Biological properties of plasma extracts with non-suppressible insulin-like activity

1. 1. Extracts of human plasma globulins with 52 (extract B) to 1775 (purified extract B) μU non-suppressible insulin-like activity (ILA) per mg protein were tested with regard to their biological properties in several insulin-assay procedures in vitro and in vivo. 2. 2. The effects of purified extract B on glucose metabolism of rat and human adipose tissue and on isolated fat cells in vitro were the same as those of crystalline insulin. Extract B stimulated the transport of glucose from the extracellular into the intracellular space of rat adipose tissue. Glycerol release of adipose tissue of fasted-refed rats was inhibited by extract B as well as by crystalline insulin in the absence of glucose in the medium. 3. 3. Incorporation of uniformly labelled [ 14C]glucose into glycogen of mouse diaphragm in vitro was stimulated by extract B as well as by crystalline insulin. 4. 4. When injected intraperitoneally into mice, extract B enhanced [ 14C]glucose incorporation into muscle glycogen and adipose tissue lipids. 5. 5. Purified extract B administered intravenously to rats lowered their serum glucose, decreased the biological half-life of serum glucose from a basal level of 18 to 9 min and enhanced the incorporation of [6- 14C]glucose into the glycogen of the diaphragm and into the total lipids of adipose tissue. Compared with crystalline insulin, the effects of purified extract B on the diaphragm clearly surpassed those on adipose tissue. 6. 6. Whereas the effects of crystalline insulin were inhibited by the simulataneous injection of anti-insulin serum, those of purified extract B were not. 7. 7. The increase of glucose assimilation brought about by these small doses of insulin and purified extract B subsided 15 min after injection, whereas the effects on the tissues remained more or less constant up to 30 min. 8. 8. The apparent inefficacy of unaltered non-suppressible ILA in human serum in vivo contrasts with its effectiveness in vitro and with the effects of extracted non-suppressible ILA in vivo. These phenomena are discussed with regard to a possible physiological role of non-suppressible ILA.

THE HOW, WHEN AND WHERE OF THE ORAL HYPOGLYCEMIC COMPOUNDS.

Juvenile-type diabetes is a contraindication to use of any oral hypoglycemic compound as the sole therapeutic agent. The best candidates for this therapy alone, without insulin, are diabetics whose disease appeared after the age of 40 years, is of less than 10 years' duration, and is stable, requiring small doses of insulin. Phenformin seems to enhance glucose utilization and to augment the action of endogenous or exogenous insulin; its use in obese diabetics has been recommended. In general, insulin-sulfonylurea combination therapy has not been effective. Phenformin-insulin therapy occasionally may be beneficial. A combination of sulfonylurea and phenformin also may be advantageous. Initial “loading doses” are no longer used.

RELATIVE EFFECTS OF INSULIN, OXYTOCIN AND VASOPRESSIN ON THE FREE FATTY ACID CONCENTRATION OF THE PLASMS OF NONDIABETIC AND DIABETIC DOGS.

The intravenous injection of oxytocin or 8-lysine-vasopressin at a rate of 2 ×10-5 pinoles per kg per hr produced a significant decrease in the concentration of the FFA of the plasma of nondiabetic and alloxandiabetic dogs. A similar decrease was not produced in the nondiabetic dog with less than 3O×1O-5 pinoles insulin per kg per hr. The alloxan-diabetic dog, however, appeared to require a smaller dose of insulin to induce the same decrease in the plasma FFA. The reduction of the plasma FFA was independent of an increased removal of glucose from the blood. Doses of oxytocin and vasopressin that significantly reduced the FFA of the plasma produced a small increase in blood glucose, while the dose of insulin that was similarly effective produced no significant change in the blood glucose concentration.

A trial of hypoglycaemic agents for weight increase in psychiatric patients.

Former attempts to restore weight loss in psychiatric patients have included hyperalimentation (Weir Mitchell, 8) and sub-coma insulin therapy (Debenham et al., 2; Sargant and Craske, 5; Sullivan, 7). The aim of the present trial was to compare weight gains in a group of patients given repeated small doses of insulin with two other groups to whom oral hypoglycaemic agents were administered, and with a control group. The drugs used were tolbutamide and chlorpropamide, both of which are sulphonylureas used in the management of diabetes mellitus, and known to induce hypoglycaemia in non-diabetic subjects (Hoenig and Gittleson, 4; Cardonnet et al., 1; Garcia Reyes et al., 3). Pharmacologically there are no qualitative differences in their mode of action. Stowers et al., (6) found the half-life of tolbutamide to be 3·5 hours and that of chlorpropamide 34·5 hours. The prolonged action of chlorpropamide permits once daily dosage, but tolbutamide, being a shorter acting drug, was given in divided doses to maintain depression of blood sugar over the 24 hours.

Experimental cytological observations on the islets of Langerhans in the tortoise (Clemmys japonica)

As has been reported in the author's previous paper (KANO 1961), apparent hydropic degeneration based upon glycogen infiltration appears in beta cells of the pancreatic islets of the tortoise (Clemmys japonica) during hibernation (from December to February). In order to know whether it is possible or not to bring about the hydropic degeneration in pancreatic beta cells by certain experimental procedures, the following experiments were carried out. Experiment 1. Tortoises (Clemmys japonica) having no hydropic beta cells in islets (in September and October) were given intraperitoneal injections of 12g of glucose per kg of body weight daily for 20 days. Experiment 2. Hibernating tortoises having hydropic beta cells in islets (in January and February) were given intraperitoneal injections of 0.3 unit of insulin and 0.2-0.3g of glucose per kg of body weight daily for 33 days. Experiment 3. Hibernating tortoises having hydropic beta cells in islets were given intraperitoneal injections of 2.4 unit of insulin per kg of body weight daily for 21 days. Experiment 4. Hibernating tortoises having hydropic beta cells in islets (in January) were kept in an incubator at 25°C to awake from the hibernation and fed ad libitum on some fish meat for 30 days.Tissues from pancreas were fixed in LEVI's solution and in ZENKER formol. Paraffin sections were cut 4μ thick and stained with hematoxylin eosin or HEIDENHAIN's azan. Glycogen was demonstrated by the periodic acid-SCHIFF method (PAS) and identified by saliva-digestion test.Experiment 1. By the prolonged intraperitoneal administrations of glucose there appeared degranulation and hydropic degeneration in beta cells of islets, alpha cells showed, however, almost no signs of hydropic change, packed by fairly large amount of alpha granules. By PAS-method much glycogen was demonstrated in islets cells, proving that the hydropic degeneration is nothing other than the glycogen infiltration of the islet cells. Besides in the islet cells the glycogen was observed abundantly in duct epithelium and centroacinous cells of the exocrine pancreatic tissue. These findings well correspond to the results of observation on control specimens taken from the hibernating animals. The hydropic degeneration of the beta cells found in this experiment may be regarded as a partial phenomenon of the widespread increase of glycogen in tissue cells caused by the hyperfunction of the beta cells and hyperinsulinemia which had been resulted by the glucose administration.Experiment 2. The prolonged intraperitoneal administration of small doses of insulin and glucose to the hibernating tortoises was not able to diminish or to take away the hydropic change from beta cells.Experiment 3. In the hibernating tortoises received large doses of insulin, the hydropic degeneration of beta cells was somewhat diminished, but never disappeared. This fact may suggest that in the cold-blooded animal like the tortoise the hydropic degeneration of islet cells found in the hibernation season should not be brought about merely by the hypoinsulinemia. It must be, however, taken into consideration that in the cold climate the hypofunction of tissue cells induced by low temperature of animals may probably inhibit the effect of insulin.Experiment 4. The beta cells were found generally packed by considerable amounts of granules and without any signs of hydropic degeneration. Alpha granules were seen in moderate amount in general. Glycogen disappeared almost completely from islet cells. This finding may indicate that accelerating suppressed function of cells during the hibernation by means of keeping the animals warm is more effective to vanish the hydropic degeneration than the administration of large doses of insulin. The low temperatur of animals induced by cold climate may presumably play an important roll in producing the so-called hydropic degeneration in islet cells during hibernation.

Exacerbatin of diabetes by excess insulin action.

Abstract 1.1. Detailed laboratory data gathered on severe diabetic subjects, in closely controlled observations and experiments, show complete lack of parallelism between the amount of insulin injected and the amount of carbohydrates utilized; even when both diet and insulin dosage are kept constant, glycosuria varies over wide ranges and the blood sugar oscillates between very low and very high levels. 2.2. The laboratory records of patients who are treated with substantial doses of insulin reveal a consistent pattern of periodic ebb and tide in the fluctuations of both the glycosuria and the glycemic level, and disclose the fact that the high tides consistently occur in the wake of hypoglycemic reactions, even after asymptomatic, mild degrees of hypoglycemia. Thus a clearcut cause and effect relationship unfolds itself between hypoglycemia and the ensuing upsurge of hyperglycemia, and we are confronted with the paradoxical fact that excess insulin action can produce hyperglycemia. It can be stated that, barring other physiological and emotional stresses, conspicuous fluctuations in glycosuria are unmistakable indicators of excess insulin action. 3.3. The impairment of carbohydrate tolerance as a sequel of hypoglycemia is readily explained on the basis of experimental evidence available in the literature and supplemented by studies in our laboratory, which show that hypoglycemia elicits an accelerated release of adrenal-pituitary blood-sugar-raising hormones. Increase in the depth and duration of the hypoglycemic state intensifies the stimulus upon the secretory activity of the adrenal-pituitary system; as a consequence the action of the blood-sugar-raising hormones can cancel out the action of injected insulin and tip the balance in favor of the former. The result is a sharp rise in the glycemic level despite the presence of active insulin, and exorbitant hyperglycemia and glycosuria after alimentation in this condition. 4.4. When hyperglycemia due to excess insulin action is countered by increasing insulin doses, under the assumption that it can only result from a deficient insulin supply, the result is exacerbation of the diabetic syndrome, manifested in extreme fluctuations of glycosuria, with mounting peaks and ketonuria; at the same time, recurrent hypoglycemic reactions increase in severity. 5.5. It is evident that in insulin therapy, avoidance of hypoglycemia, even of mild, asymptomatic degrees, is no less important than the control of excessive hyperglycemia and glycosuria. Application of this precept makes it possible to forestall the development of severe states of diabetes, and to restore patients with severe diabetes to a status of mild diabetes that can be satisfactorily managed with small doses of insulin or, not infrequently, without insulin.