Inhibition by (-)-deprenyl of agonist-evoked contractions in rabbit aorta

The effect of (-)-deprenyl, a relatively selective MAO-B inhibitor, was examined for its ability to inhibit the contractions of rabbit isolated aorta evoked by various agonists and potassium. (-)-Deprenyl (10(-5)-3 x 10(-4) M) antagonized the contractions evoked by noradrenaline (10(-8)-3 x 10(-4) M); pA2: 5.10. The antagonism was reversible. It was attenuated by cocaine (3 x 10(-5) M); pA2: 4.38, unchanged by corticosterone (4 x 10(-5) M); pA2 4.79 and enhanced by cocaine (3 x 10(-5) M) plus corticosterone (4 x 10(-5) M); pA2: 5.48. (+)-Deprenyl (10(-6)-10(-4) M) did not alter the contractions evoked by noradrenaline (3 x 10(-9)-10(-4) M). Clorgyline (10(-5) and 10(-4) M) antagonized the noradrenaline-evoked contractions. Pargyline (10(-4) and 3 x 10(-4) M) had no effect. (-)-Deprenyl (10(-5)-3 x 10(-4) M) antagonized the contractions evoked by phenylephrine (10(-8)-10(-4) M); pA2: 5.10. Removal of the endothelium did not alter the antagonism; pA2: 5.35. (-)-Deprenyl (10(-5)-3 x 10(-4) M) antagonized the contractions evoked by either 5-hydroxytryptamine (3 x 10(-8)-3 x 10(-4) M); pA2: 4.61 or by histamine (10(-6)-3 x 10(-2) M); pA2: 4.84. (-)-Deprenyl (3 x 10(-4) M) caused a noncompetitive antagonism of the contractions evoked by potassium (1.5-5.5 x 10(-2) M). It is concluded that (-)-deprenyl is a weak inhibitor of postjunctional alpha 1-adrenoceptors, 5-hydroxytryptamine (5-HT2) receptors, and histamine (H1) receptors.

Growth hormone administration stimulates energy expenditure and extrathyroidal conversion of thyroxine to triiodothyronine in a dose-dependent manner and suppresses circadian thyrotrophin levels: studies in GH-deficient adults

OBJECTIVE

The impact of exogenous GH on thyroid function remains controversial although most data add support to a stimulation of peripheral T4 to T3 conversion. For further elucidation we evaluated iodothyronine and circadian TSH levels in GH-deficient patients as part of a GH dose-response study.

PATIENTS

Eight GH-deficient adults, who received stable T4 substitution due to central hypothyroidism; two patients, who were euthyroid without T4 supplementation were studied separately.

DESIGN

All patients were initially studied after at least 4 weeks without GH followed by 3 consecutive 4-week periods in fixed order during which they received daily doses of 1, 2 and 4 IU of GH/m2 body surface area. The patients were hospitalized for 24 hours at the end of each period.

MEASUREMENTS

Circulating total and free concentrations of T4 and T3, total rT3 and TSH were measured once at the end of each study period. Circadian TSH levels were recorded during the period without GH and during GH treatment with 2 IU GH.

RESULTS

Highly significant GH dose-dependent increases in total and free T3 and a reduction in rT3 were observed. The T3/T4 ratio also increased with increasing GH dosages (P < 0.001). In seven patients subnormal T3 levels were recorded in the period off GH, despite T4 levels well within the normal range. Resting energy expenditure also increased and correlated with free T3 levels (r = 0.47, P < 0.05). The circadian TSH levels exhibited a significant nocturnal increase during the period without GH, whereas GH therapy significantly suppressed the TSH levels and blunted the circadian rhythm (mean TSH levels (mU/l) 0.546 +/- 0.246 (no GH) vs 0.066 +/- 0.031 (2 IU GH) (P < 0.05)). The two euthyroid non-T4 substituted patients exhibited qualitatively similar changes in all parameters.

CONCLUSIONS

GH administration stimulated peripheral T4 to T3 conversion in a dose-dependent manner. Serum T3 levels were subnormal despite T4 substitution when the patients were off GH but normalized with GH therapy. Energy expenditure increased with GH and correlated with free T3 levels. GH caused a significant blunting of serum TSH. These findings suggest that GH plays a distinct role in the physiological regulation of thyroid function in general, and of peripheral T4 metabolism in particular.

Effects of captopril on ambulatory blood pressure, renal and cardiac function in microalbuminuric type 1 diabetic patients

OBJECTIVE

To study the effect of Captopril on ambulatory blood pressure, renal and cardiac function and extracellular volume in microalbuminuric Type 1 diabetic patients.

DESIGN

Randomized, double blind placebo controlled study of two years duration.

SETTING

University clinic.

PATIENTS

Twenty-two patients without hypertension.

INTERVENTION

Patients received 50 mg Captopril or placebo twice a day.

MEASUREMENTS

Ambulatory blood pressure, renal function, extracellular volume, and echocardiographic indices of cardiac function and dimensions were assessed annually. Clinic blood pressure and urinary albumin excretion were measured every 3 months.

RESULTS

Twenty-four hour mean arterial blood pressure was unchanged in the Captopril group (mean +/- SD) (baseline 93 +/- 4 and follow up 91 +/- 8 mmHg) and in the placebo group (96 +/- 7 and 97 +/- 10 mmHg, NS). Night/day ratio of blood pressure was unaffected. Glomerular filtration rate was unchanged and renal plasma flow increased in the Captopril (557 +/- 97 and 600 +/- 112 ml min-1) versus the placebo group (574 +/- 85 and 535 ml min-1, p = 0.05). Filtration fraction was reduced in the Captopril versus the placebo group (p < 0.05). Extracellular volume and echocardiographically derived parameters were unaffected. The relative change in day time mean arterial blood pressure in the Captopril group correlated with changes in urinary albumin excretion (Spearmans r = 0.85, p < 0.05) unlike clinic mean arterial blood pressure (r = 0.33, p = 0.35).

CONCLUSION

Diurnal rhythm of blood pressure was unaffected by long term administration of Captopril. Renal plasma flow was increased and filtration fraction reduced. A significant association between changes in urinary albumin excretion and blood pressure after Captopril was revealed only by the implementation of ambulatory blood pressure measurements.

Insulin-like growth factors (IGF)-I and -II and IGF binding protein-1, -2, and -3 in patients with acromegaly before and after adenomectomy

The interrelationship between insulin-like growth factors (IGFs) and their major binding proteins (IGFBPs) as a function of disease activity in acromegaly has not previously been prospectively evaluated. We studied basal and insulin-stimulated serum levels of IGF-I and -II and IGFBP-1, -2, and -3 in six acromegalic patients before and 2 months after successful adenomectomy compared with a group of sex- and age-matched healthy, untreated subjects. All were studied postabsorptively (11 AM) and at the end of a 2-hour euglycemic glucose clamp (0.4 mU insulin/kg x min). Serum IGF-I levels (mean +/- SE) were elevated in acromegaly but were normalized following therapy (basal state IGF-I [micrograms/L], 857 +/- 119 [active] v 255 +/- 65 [postoperative] v 190 +/- 20 [control]). Serum IGF-II levels did not change following therapy and were similar to those of the control group. IGF levels did not change during the clamp. Serum IGFBP-3 levels were elevated in active acromegaly, but were normalized after therapy (basal state IGFBP-3 [micrograms/L] 6,983 +/- 612 [active] v 3,939 +/- 504 [postop] v 3,358 +/- 125 [control]). The molar ratio of (IGF-I+IGF-II): IGFBP-3 was similar in all studies. Serum IGFBP-1 interacted significantly with time in all studies, exhibiting a gradual decrease in the basal state and ensued by further suppression during the clamp. Insulin and IGFBP-1 correlated inversely in the pooled data and in the acromegalic patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum growth hormone (GH) profiles after nasally administered GH in normal subjects and GH deficient patients

OBJECTIVE

GH-deficient patients are at present treated with daily subcutaneous GH injections. Further improvements in patient compliance and effects of treatment may occur with nasal administration. We have examined the absorption of nasally administered GH in healthy subjects and in GH deficient patients in two separate studies.

DESIGN

Healthy subjects and GH deficient patient were examined in the morning after an overnight fast. Twelve IU of GH in a powder containing didecanoyl-L-alpha-phosphatidylcholine as enhancer were administered in the nostrils (6 IU in each nostril) at the beginning of the study in the healthy subjects. The GH deficient subjects received a total of 6 IU GH/m2 intranasally. Blood was frequently sampled for up to 4 hours. Before and after nasal application anterior rhinoscopy was performed.

PATIENTS

Eight normal subjects and 7 GH deficient patients.

MEASUREMENTS

Serum GH.

RESULTS

(mean +/- SD) Mean maximum concentration (Cmax) in the normal group was 57.6 mU/l +/- 36.9 with a mean time to obtain Cmax (Tmax) of 65 +/- 47 min. In the GH deficient group Cmax was 56.1 +/- 26.1 mU/l with a mean Tmax of 45 +/- 15 min. The subjects did not report any major inconvenience during the study. Anterior rhinoscopy did not reveal changes.

CONCLUSION

Nasally administered GH is absorbed to a significant degree from the nasal mucosa without obvious untoward effects in the short term. These data encourage further studies with nasal GH administration.

Adult growth hormone deficiency

Several reports have focused on the clinical features of the untreated GH-deficient adult and the effect of GH therapy. The results reported are strikingly unanimous. Untreated GH-deficient adults have been shown to have increased cardiovascular mortality, reduced exercise capacity, reduced muscle strength, subnormal glomerular filtration rate and renal plasma flow, defective sweat secretion and defective thermoregulation, reduced energy expenditure and basal metabolic rate, abnormal thyroid hormone metabolism, reduced myocardial function and clinical signs of premature atherosclerosis. Body composition has been found abnormal with increased fat mass, decreased lean body mass, decreased muscle fat ratio, visceral obesity, reduced extracellular fluid volume and reduced bone mineral content. Furthermore, two independent groups have reported impaired psychological wellbeing as compared to normal subjects. Apart from the observation on total mortality, all the above-reported abnormalities improve during GH substitution. The only recognisable side effects so far has been fluid retention, which is usually transient and dose-dependent. It is concluded that GH deficiency has distinct clinical consequences all of which can be totally or partially alleviated by GH replacement therapy.

Marked effects of sustained low growth hormone (GH) levels on day-to-day fuel metabolism: studies in GH-deficient patients and healthy untreated subjects

The metabolic effects of circadian GH levels in the very low physiological range are unknown. Therefore, we studied 1) GH-deficient patients on receiving GH replacement therapy in whom the last GH injection was replaced with a constant iv infusion starting at 24 h of either GH (35 micrograms/h) or saline (SAL), and 2) an untreated healthy control group. Glucose turnover, indirect calorimetry, and forearm exchange of metabolites were investigated the following day in the basal state (8-11 h) and during a euglycemic (11-13 H) and a hypoglycemic (13-14 h) glucose clamp. During infusion, steady state GH levels increased by 1.9 micrograms/L. Basal and insulin-stimulated energy expenditures (EE) were lower in the patients during SAL than during GH infusion, and the basal respiratory exchange ratio was also lower during GH treatment. Protein EE was elevated during SAL compared to GH infusion (P < 0.05). During the clamp, forearm glucose uptake decreased in the GH study compared to that in the SAL study ((P < 0.05). The patients in the SAL study were more sensitive to insulin during the clamp in terms of suppression of endogenous glucose production (EGP; P < 0.05) and infusion rate of glucose necessary to maintain euglycemia (M value; P < 0.01). Lipid oxidation, in particular in the basal state, was decreased during SAL compared to GH infusion (P < 0.01). The SAL-treated compared with the control group was characterized by decreased basal and insulin-stimulated EE (P < 0.01), increased protein EE (P < 0.01), and hypersensitivity to insulin in terms of suppression of EGP (P < 0.05) and M value (P < 0.01). During the hypoglycemic clamp, the patients in the SAL study were hypersensitive to the hypoglycemic actions of insulin in terms of increased M-value and suppression of EGP, and lipolysis was impaired, as judged by the inhibition of net forearm uptake of FFA. In conclusion, very low GH levels exert powerful actions on day-to-day metabolism, resulting in protein and glucose sparing at the expense of lipids.

Effect of growth hormone administration on circulating levels of luteinizing hormone, follicle stimulating hormone and testosterone in normal healthy men

A new area of growth hormone (GH) therapy in adults is the treatment of infertility. The aim of this study was to evaluate the effects of pharmacological GH administration on the secretion of pituitary and gonadal hormones in normal men. Eight healthy men, 23-32 years of age (mean 28.1 years), with a normal body mass index were studied in a double-blind, placebo-controlled crossover design. All participants had a normal semen analysis before entering the study. Each participant was treated with placebo and GH (12/IU/day, Norditropin; Novo Nordisk, Denmark) during two different 14-day periods, separated by a 6 week washout period. Administration of GH for 14 days resulted in a significant increase in serum insulin-like growth factor I (IGF-I; P < 0.01) but no changes occurred in IGF-I values during placebo treatment. The concentrations of follicle stimulating hormone and luteinizing hormone displayed no change during the two periods and did not differ between the GH treatment period and the placebo period. The concentration of testosterone was unchanged during the placebo/GH periods and there was no difference between the GH treatment period and the placebo period. We conclude that GH treatment for 14 days in normal healthy men does not affect gonadotrophin or testosterone patterns.

Impact of 2 weeks high dose growth hormone treatment on basal and insulin stimulated substrate metabolism in humans

OBJECTIVE

Short-term, high dose growth hormone (GH) treatment has been advocated in many catabolic disease states. It is likely that some of the anabolic effects of GH are mediated through activation of lipolysis, but the metabolic impact of therapeutically relevant GH exposure is not known in detail. The present study was accordingly designed to assess the effects of such GH exposure on basal and insulin stimulated intermediary metabolism.

DESIGN, PATIENTS AND MEASUREMENTS

Six healthy young females were examined following daily injections of GH (12 IU/day) or saline for 2 weeks in a placebo controlled design. Each study consisted of a 3 hour basal period and a 2 hour hyperinsulinaemic euglycaemic clamp.

RESULTS

GH treatment caused (1) increased levels of IGF-I (382 +/- 46 vs 294 +/- 22 micrograms/l, P < 0.05) and (2) increased basal values of free fatty acids (714 +/- 40 (GH) vs 634 +/- 64 (placebo) mumol/l, P < 0.05), 3-hydroxybutyrate (118.3 +/- 42.8 (GH) vs 57.7 +/- 21.6 (placebo) mumol/l, P < 0.05), glycerol (54.3 +/- 8.2 (GH) vs 41.4 +/- 8.4 (placebo) mumol/l, P < 0.05) and forearm uptake of 3-hydroxybutyrate, together with increments of plasma glucose (5.28 +/- 0.11 (GH) vs 4.87 +/- 0.16 (placebo) mmol/l, P < 0.05). Basal forearm uptake of glucose, isotopically determined glucose turnover and serum levels of GH, insulin and C-peptide were unaltered. During the clamp GH treatment was associated with (1) a 40% decrease in the administered amount of glucose (M-value) (P < 0.05) and (2) a 70% decrease in forearm glucose uptake (P < 0.05). Indirect calorimetry revealed a 15% increase in resting energy expenditure (P < 0.05) and a decreased basal respiratory exchange ratio (0.75 (GH) vs 0.80 (placebo), P < 0.05), presumably reflecting increased lipid oxidation.

CONCLUSIONS

Administration of GH in a therapeutic dose for 2 weeks, despite apparently normal daytime levels of major metabolic hormones, induces significant increases in circulating lipid fuel substrates, increased energy expenditure and lipid oxidation, together with insulin resistance. Such effects should be considered when applying GH treatment schedules clinically.

Effects of octreotide on insulin-like growth factor I and metabolic indices in growth hormone-treated growth hormone-deficient patients

Animals studies have demonstrated that in addition to inhibiting growth hormone (GH) secretion octreotide inhibits in a direct manner hepatic or peripheral insulin-like growth factor I (IGF-I) generation. To test this hypothesis in humans we studied ten GH-deficient patients with frequent blood sampling during 38 h on two occasions. Regular GH therapy was discontinued 72 h prior to each study period. At the start of each study a subcutaneous (sc) injection of GH (3 IU/m2) was given (at 18.00 h). In a single-blinded crossover design, patients received a continuous sc infusion of either octreotide (200 micrograms/24 h) or placebo (saline). The pharmacokinetics of GH were similar on the two occasions. The area under the curve +/- SEM of serum GH was 142.5 +/- 53.6 micrograms.l-1 x h-1 (octreotide) and 144.8 +/- 41.8 micrograms.l-1 x h-1 (placebo), (p = 0.73); Cmax (microgram/l) was 12.5 +/- 1.47 (octreotide) and 12.8 +/- 1.42 (placebo) (p = 0.83), and Tmax (h) was 6.1 +/- 0.97 (octreotide) and 5.2 +/- 0.65 (placebo) (p = 0.49). Growth hormone administration was associated with an increase in serum IGF-I (microgram/l), which was identical during the two studies, from 85.3 +/- 19.4 to 174.25 +/- 30.3 for octreotide and from 97.0 +/- 26.4 to 158.8 +/- 28.2 for placebo. Mean IGF-I levels (microgram/l) were 138.2 +/- 25.1 (octreotide) and 134.5 +/- 28.6 (placebo) (p = 0.78). Similarly, the increase in IGF binding protein 3 (IGFBP-3) levels was identical. Mean IGFBP-3 levels (microgram/l) were 2303 +/- 323 (octreotide) and 2200 +/- 361 (placebo) (p = 0.25).(ABSTRACT TRUNCATED AT 250 WORDS)

Growth hormone dose regimens in adult GH deficiency: effects on biochemical growth markers and metabolic parameters

OBJECTIVE

We examined the effects of different doses of GH on insulin-like growth factor I (IGF-I), IGF binding protein 3 (IGFBP-3), body composition, energy expenditure, and various metabolites in GH deficient adults, in order to approach a metabolically appropriate GH dosage in young GH deficient adults.

DESIGN

Ten GH deficient patients (age 21-43) were studied after 4 weeks without GH followed by three consecutive 4-week periods, where the patients received in a fixed order GH 1, 2 and 4 IU/m2 s.c. per day. At the end of each period the patients were hospitalized for a 24-hour examination.

RESULTS

Mean 24-hour levels of GH (mIU/l) were 2.7 +/- 0.3 (0 GH), 7.2 +/- 0.9 (1), 10.8 +/- 1.5 (2) and 18.9 +/- 2.7 (4 IU/m2) (mean +/- SEM) (P < 0.01). Likewise, IGF-I levels increased dose dependently from 61 +/- 21 to 206 +/- 65, 260 +/- 70 and 468 +/- 171 micrograms/l (P < 0.05); serum IGF-I in an age and sex matched control group was 248 +/- 25 micrograms/l. Corresponding serum IGFBP-3 levels also increased from 1860 +/- 239 to 3261 +/- 379, 3762 +/- 434 and 4384 +/- 652 micrograms/l (P = 0.01) respectively. Significant increases in diurnal serum insulin levels after 4 IU/m2 were recorded, whereas plasma glucose levels remained unchanged. Lipid intermediates increased dose independently during GH administration. GH caused a significant increase in resting energy expenditure, whereas the respiratory exchange ratio was unaltered. Fat mass was increased without GH therapy and decreased during the study. Four patients made complaints during 4 IU/m2 GH administration, probably related to GH induced fluid retention.

CONCLUSION

Based primarily on IGF-I and IGFBP-3 levels our data suggest that a GH replacement dose in young GH deficient adults in the order of 1-2 IU/m2 per day is adequate. This is a relatively low dose as compared to dose regimens in children and adolescents.

The effect of low-dose supplementation with n-3 polyunsaturated fatty acids on some risk markers of coronary heart disease

Epidemiological data have suggested that a low dose of dietary n-3 polyunsaturated fatty acids from seafood may protect against coronary heart disease. We studied the effect of supplementation with a low dose of very long-chain n-3 fatty acids (0.65 g day-1) on plasma lipids, haemostasis, and neutrophil aggregation. Twenty-four healthy subjects were randomized to supplementation with very long-chain n-3 fatty acids or a control oil for 8 weeks. Laboratory analyses were done twice before and twice at the end of the supplementation period. The supplement with n-3 polyunsaturated fatty acid did not significantly affect plasma lipids or plasma levels of fibrinogen, factor VII, plasminogen activator inhibitor, whole blood aggregation or aggregability of neutrophil leukocytes. Therefore, the potential beneficial effect of very long-chain n-3 fatty acids in coronary heart disease is likely to be mediated through other mechanisms.

[Influence of various therapeutic models on survival after prehospital cardiac arrest]

We analyzed the outcome after prehospital cardiac arrest in a part of greater Copenhagen. Four different emergency medical systems were acting: a system providing basic life support only (group 1), a system providing basic life support and early defibrillation (group 2), a system providing basic life support followed by advanced cardiac life support (group 3), and a system providing basic life support and early defibrillation followed by advanced cardiac life support (group 4). Over a 2-year period 624 cases of cardiac arrest were reported, 34 were discharged from hospital. The survival to discharge from hospital and the one-year survival were significantly better in group 4. Our data reconfirm that early advanced cardiac life support improves survival rates for prehospital cardiac arrest.

Insulin-like growth factors (IGF) I and II and IGF binding proteins 1, 2 and 3 during low-dose growth hormone (GH) infusion and sequential euglycemic and hypoglycemic glucose clamps: studies in GH-deficient patients

To evaluate the short-term effects of growth hormone (GH), insulin and different levels of glycemia on insulin-like growth factors (IGF) I and II and IGF binding proteins (IGFBP) 1, 2 and 3, we studied six GH-deficient adolescents during a night and the following day in the postabsorptive (basal) state followed by sequential euglycemic (5 mmol/l) and hypoglycemic (3 mmol/l) glucose clamps concomitant with an intravenous infusion (starting at 24.00 h) of GH (35 micrograms/h) or saline. Current GH therapy was withdrawn 24 h prior to each study. Nocturnal levels of IGF-I, IGF-II, IGFBP-2 and IGFBP-3 remained stable during both studies. Nocturnal serum IGFBP-1 increased and correlated inversely with insulin in both studies. Regression analysis revealed a significant inverse correlation between mean nocturnal IGFBP-2 and IGFBP-3 levels. During the daytime, serum IGF-I declined slowly during saline infusion, whereas serum IGF-II remained stable in both studies. Serum IGFBP-1 displayed a gradual significant decline during the basal state and the euglycemic and hypoglycemic clamps seemed to be unaffected by GH levels. By contrast, serum IGFBP-2 remained stable during the same period in both the GH and the saline study. Serum IGFBP-3 declined insignificantly during the daytime in the saline study.(ABSTRACT TRUNCATED AT 250 WORDS)

Defective T-cell stimulatory pathways in patients after allogeneic bone marrow transplantation (BMT) in man

Immunological reconstitution after allogeneic bone marrow transplantation in man is characterized by a decreased lymphocyte transformation response to various mitogens and antigens during a period of from months to years. One reason for the decreased proliferative capability could be an inverted CD4/CD8 ratio; however, the present investigation demonstrates that this is not the only explanation for the immunodeficiency, since the CD4 as well as the CD8 subset, when studied in isolation, have qualitative defects, as evidenced by a reduced response of both subsets to stimulation with PHA, anti-CD2 and anti-CD3 MABs. The reason for the qualitative defect is unknown but a distorted composition of the CD4+ as well as the CD8+ T-cell subsets is suggested by the present investigations. We also observed that the PHA response was almost completely reconstituted one year after BMT, while the PWM response was still severely affected. The present study suggests that T-cell subsets which differ in their capacity to respond to PHA and PWM have different kinetics of reconstitution after BMT.

Subcutaneous absorption kinetics of two highly concentrated preparations of recombinant human growth hormone

OBJECTIVE

The relative bioavailability of two highly concentrated (12 IU/ml) formulations of biosynthetic human growth hormone (GH) administered subcutaneously was compared.

DESIGN

A randomized, crossover study. Conventional GH therapy was withdrawn 72 hours before each study period. There was a washout period of at least four weeks between the study periods.

SETTING

Participants were recruited from an outpatient clinic and were hospitalized during the two study periods.

PATIENTS

Fourteen GH-deficient patients (mean age 25.2 y, range 14-54). One patient was excluded from data analysis because of signs of endogenous GH secretion.

INTERVENTIONS

At the start of each study period, GH 3 IU/m2 was injected subcutaneously. The two formulations, PenFill and PenSet, differ in the buffers used and in the relative content of mannitol and glycine. Serum profiles of GH were monitored frequently for 24 hours. Samples were taken every 30 minutes for 6 hours and then hourly.

MAIN OUTCOME MEASURES

Bioavailability (F) and absorption dynamics of human GH were measured. The relative absorption fractions estimated from the areas under the individual serum concentration curves from 0 to 24 hours, and the observed time (Tmax) to reach the maximum concentration (Cmax) were determined. Short-term metabolic effects of GH on insulin-like growth factor (IGF-I), glucose, and insulin were determined.

RESULTS

The geometric mean (SD) of F was 0.910 (1,236). The 90 percent confidence interval was 0.819-1.010. Mean (+/- SD) of Cmax was 12.65 +/- 5.89 and 12.58 +/- 4.40 ng/mL for PenFill and PenSet, respectively. Corresponding values for Tmax were 5.49 +/- 1.55 and 5.89 +/- 1.79 hours for PenFill and PenSet, respectively. There was a considerable interindividual variation, but the relative absorption fraction did not significantly differ from 1 (p = 0.13). Neither Cmax (p = 0.74) nor Tmax (p = 0.58) of the two formulations was significantly different. Injection of the two formulations induced similar increments in serum IFG-I (p = 0.48). Serum insulin and blood glucose concentrations were not significantly different.

CONCLUSIONS

There is no significant difference between the absorption kinetics and short-term metabolic effects of these two highly concentrated formulations of biosynthetic GH. The two formulations are bioequivalent.

Effect of oral calcium supplementation on blood pressure in patients with previously untreated hypertension: a randomised, double-blind, placebo-controlled, crossover study

It has been claimed that calcium lowers BP. The present randomised, double-blind, placebo-controlled crossover study is the first to investigate the effect on BP of a high oral dose of calcium given for a long period to patients with previously untreated hypertension. Elemental calcium (2 g) was administered for 12 weeks interchanging with a period of 12 weeks of placebo. Twenty patients completed the protocol. There was no significant difference in change of BP during the period of additional calcium intake when compared with placebo (P = 0.33). The risk of not detecting a real BP-lowering effect of calcium of at least 3 mmHg was < 5%. No evidence for the existence of a subgroup of 'responders' was found. It is concluded that a high daily dose of calcium supplementation given for 12 weeks does not decrease BP in previously untreated patients with mild to moderate hypertension.

Lack of impact of pharmacological growth hormone administration on circulating levels of reproductive hormones during the menstrual cycle in normal women

OBJECTIVE

To evaluate the effects of pharmacological growth hormone (GH) administration on the secretion of pituitary and gonadal hormones during the menstrual cycle in normal women.

DESIGN

Randomized, double-blind, placebo-controlled crossover design.

PATIENTS, PARTICIPANTS

Six normally menstruating, healthy women, 22 to 24 years of age and with a normal body mass index.

INTERVENTIONS

Each participant was treated with placebo and growth hormone (12 IU/d) during two different 14-day periods, separated by a 6-week washout period.

MAIN OUTCOME MEASURES

Serum insulin-like growth factor I (IGF-I), estradiol, progesterone, follicle-stimulating hormone, and luteinizing hormone.

RESULTS

Administration of GH for 14 days resulted in a significant increase in serum IGF-I, whereas no changes occurred in gonadotropin or sex steroid response.

CONCLUSIONS

Growth hormone treatment during the first 14 days of menstrual cycle in normal women does not affect gonadotropin or sex steroid patterns.

Assessment of glucose turnover rates in euglycaemic clamp studies using primed-constant [3-3H]-glucose infusion and labelled or unlabelled glucose infusates

Underestimation of glucose turnover rates has been a problem in clamp studies using primed-constant [3-3H]-glucose infusion technique. Due to slow mixing in interstitial compartments concealed specific activity gradients may arise between plasma and interstitial compartments during intravenous unlabelled glucose infusion. Such specific activity gradients, however, can be prevented if plasma specific activity is maintained constant. Two euglycaemic clamp studies (insulin infusion 40 mU m-2 min-1) were performed in six lean normal subjects. Using conventional unlabelled glucose infusates plasma specific activity declined by 74%, tracer determined glucose appearance was smaller than actual glucose infusion rates (317 +/- 11 vs 366 +/- 15 mg m-2 min-1, p < 0.001), and erroneous negative values were calculated for glucose production (- 49 +/- 7 mg m-2 min-1). Average underestimation during the first 2 h correlated with glucose infusion rates (r = 0.88, p < 0.02). In contrast, when plasma specific activity was maintained constant, using appropriately labelled glucose infusates, tracer determined glucose appearance and glucose infusion rates were similar (385 +/- 16 vs 385 +/- 17 mg m-2 min-1), and negative errors for glucose production were avoided. In conclusion, using unlabelled glucose infusates, as in previous studies, suppression of glucose production is overestimated and stimulation of glucose utilization is underestimated. As errors were greater with larger glucose infusions, the mistakes may have been greatest in insulin sensitive control subjects, and smaller in insulin resistant subjects. Therefore, re-evaluation of hepatic insulin sensitivity seems appropriate in diabetes, obesity, and other insulin resistant states.

[Hepatocellular adenoma after oral contraception]

Raised serum basic phosphatase was found incidentally in a woman aged 43 years. Investigation with biopsy revealed a hepatocellular adenoma. The tumour regressed after withdrawal of Neogentrol oral contraception which the patient had consumed for 17 years. The patient did not desire invasive treatment. Employment of oral contraceptive steroids for more than two years is associated with increased occurrence of hepatocellular adenomata. The hepatocellular adenoma is a clearly delimited, most frequently solitary, benign tumour with limited malignant potential but with a considerable risk of rupture with haemorrhage even after withdrawal of oral contraception. The hepatocellular adenoma has no malignant tumour vessels (in contrast to hepatocellular carcinoma) and it appears as a cold region on scintigraphy (in contrast to focal nodular hyperplasia), but the diagnosis can only be established with certainty by histological examination. The hepatocellular adenoma consists most frequently of large pale hepatocytes in trabeculae surrounded by a net of reticulin and separated by sinusoids. Biliary passage and portal spaces do not occur. The best treatment consists of excision of the tumour or embolisation. If invasive treatment is postponed, regular scanning should be performed to observe regression or progression of the tumour and oral contraception and pregnancy should be advised against on account of the risk of growth of the tumour.

[A hypersensitive reaction after radiography of the colon]

A case of systemic allergic reaction following barium enema is described. The reaction was most probably provoked by a latex balloon on the rectal catheter.

Effect of piroxicam in addition to continuous thoracic epidural bupivacaine and morphine on postoperative pain and lung function after thoracotomy

Twenty-eight patients scheduled for lung resection with lateral thoracotomy and postoperative chest drains during combined thoracic epidural bupivacaine plus morphine and general anaesthesia were studied. Postoperative pain treatment was continuous epidural infusion of bupivacaine 0.25% 5 ml h-1 plus morphine 0.2 mg h-1 for 48 h and, in addition, the patients received rectal piroxicam 40 mg randomly and double-blind 12 h and 1 h before surgery and 20 mg 24 h-1 postoperatively or placebo. Pain was evaluated at rest, during cough and mobilisation, together with pulmonary function (FEV1, FVC, PEFR) and sensory level of analgesia repeatedly for 48 h. The results showed efficient pain relief, but without differences in pain scores or need for supplementary analgesics between the two groups. Pulmonary function decreased similarly in the two groups. Thus we were unable to show enhanced analgesia by supplementing an otherwise effective low-dose epidural bupivacaine and morphine treatment with piroxicam after thoracic surgery with chest drains.