GH secretory dynamics and responsiveness to SMS 201-995 treatment in acromegaly

Recently, SMS 201-995, a long acting somatostatin analogue, has been used in successful therapy for inhibition of growth hormone (GH) levels in acromegaly. But, it was reported that inhibitory and clinical effects in the individual patient were different in many cases. Therefore, to find the predictive factor for patients with effective inhibition of GH, we investigated the paradoxical response to thyrotropin releasing hormone (TRH), growth hormone releasing hormone (GHRH) and diurnal variation of GH secretion between responders and non-responders to SMS 201-995. The results were as follows; Responders, patients with suppressive response to SMS 201-995, totalled 4 of 8 patients. The paradoxical response of GH to TRH was observed in 3 of 4 responders and 3 of 4 non-responders. The response of GH to GHRH was not noted in either of the groups. The diurnal variation of GH secretion showed in one of the responders and in 3 of the non-responders. These results suggested that the absence of diurnal variation of GH secretion was a characteristic feature of responders to SMS 201-995 and thus diurnal variation of GH secretion could be used as a predictive factor for SMS 201-995 therapy, and the pathogenetic mechanism of acromegaly might be dependent on the controlled regulation of GHRH and endogenous somatostatin.

Prenatal diagnosis of a heterozygote of salt wasting congenital adrenal hyperplasia due to 21-hydroxylase deficiency by genetic linkage analysis

For the purpose of prenatal diagnosis of CAH, genetic linkage analysis by HLA genotyping with lymphocytes and cultured amniotic cells were performed in a family at risk in which two consecutive children had been affected with SW CAH. In addition, the response of serum 17-OHP to intravenous ACTH was determined in obligate carrier parents, and 17-OHP concentration of amniotic fluid was also measured at 16 weeks of gestation. As might be expected, the baseline levels of 17-OHP in obligate parents were significantly higher than that of normal control. Although the post stimulation response of 17-OHP to ACTH in the mother (I-2) was significantly higher than that of normal control, the post stimulation levels of 17-OHP were in normal range in the father (I-1). The 17-OHP level (5.7 ng/ml) in the amniotic fluid showed intermediate value compared to Pang's report (normal less than 30 ng/ml, CAH greater than 12.0 ng/ml) suggesting heterozygote of the fetus. Genetic linkage analysis by HLA genotyping with cultured amniotic cells revealed heterozygote in their fetus (II-3) who has received one chromosome No,6 containing HLA haplotype A24, B40, Cw3 (normal allele for 21-OH) from the father and the other chromosome No,6 containing HLA haplotype A2, Bw62, Cw4 (mutant allele for 21-OH D) from the mother. In conclusion, attempts to detect heterozygote for 21-OH deficiency by ACTH stimulation test were partially successful and prenatal diagnosis of CAH by the hormone studies in ammiotic fluid requires reliable values in normal, heterozygotes and patients group, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of long acting somatostatin analogue SMS 201-995 in acromegaly

Somatostatin is a potent inhibitor of the growth hormone (GH) secretion. However, the short half-life as well as the rebound phenomenon have rendered it impractical for therapeutic use. SMS 201-995, a long acting somatostatin analogue, has been shown to have a long acting inhibitor effect on GH secretion. To observe its suppressive effect on GH secretion and to determine whether it has a diabetogenic effect and whether it can suppress the paradoxical response of GH, we administered 50 μg of SMS 201-995 subcutaneously to five acromegalic patients before breakfast. Serum GH was reduced 85% from the basal concentration four hours after the administration of SMS 201-995 and remained below the basal level for up to eight hours without a rebound phenomenon. The pattern of glucose intolerance was observed in 4 out of 5 patients but not in the normal controls; it seemed to be caused by exessive GH. Also SMS 201-995 did not suppress postprandial insulin and glucagon secretion. In addition, we observed that SMS 201-995 suppressed the paradoxical release of GH to TRH in two of three patients who showed a paradoxical response. Unexpectedly one patient who had no paradoxical response before the administration of SMS 201-995 showed a paradoxical response. In conclusion, we suggest that more than 50 μg of SMS 201-995 should be given at least 3 times a day for adequate adjunctive therapy of acromegaly. The SMS 201-995 has no diabetogenic effect.

Effect of naloxone on counter insulin hormone secretion in insulin-induced hypoglycemia

To investigate the normal physiologic role of endogenous opiates in glucose homeostasis and as a preliminary study for clarifying the association of endogenous opites with pathophysilogy of NIDDM, we obseved the changes in the secretion of counter-insulin hormones in response to insulin-induced hypoglycemia with or without naloxone.

The results were as follows: Blood glucose was decreased significantly more rapidly with naloxone infusion than after insulin alone, which seems to play a role in the early responses of ACTH and GH. Not only was the more rapid response of ACTH and GH, but also the prolonged secretion of ACTH and Cortisol were observed after administration of insulin and naloxone.

We concluded that endogenous opiates may be involved in the feedback regulation of secretion of ACTH and GH during hypoglycemia either at hypophysis or hypothalamus, and involved in glucose homeostasis via a certain direct mechanism other than regulation of counter hormone secretion.

Possible correlation between non-insulin dependent diabetes mellitus (NIDDM) and restriction fragment length polymorphism (RFLP) of the 5'-flanking region of insulin gene in Korean diabetic population

Restriction fragment length polymorphism (RFLP) is a new and precise method for the detection of the disease on the molecular level. The genetic background of Non-insulin dependant diabetes mellitus (NIDDM) has been strongly suggested, but its occurrences are obvious for other expession factors. We first investigated insulin gene polymorphism in twenty-nine Korea NIDDM patients and 11 non-diabetic controls. We found 91 percent and 86 percent of the genotype 1/1 in diabetics and controls respectively. Also genotype 1/3 was found 9 percent and 14 percent each in both groups. Genotype 3/3 revealed 0 percent in two groups. Four acromegalics who had secondary DM showed only genotype 1/1. These findings showed that class 3 allele(2.4 kb) was a weak genetic marker of NIDDM, and had a faint correlation.

Development of immunoassay methods by use of liposomes

In order to develop liposomes for use in an immunoassay system, the preparation of immune liposomes and their characterization have been investigated. Liposomes have potential use in extremely sensitive analytical immunoassays, in addition to serving as an attractive drug delivery system. This liposome immunoassay system is based on membrane immunochemistry and an enzymatic reaction. An intense yellow color, easily detectable with the naked eye, was produced quite rapidly by the lysis of bovine serum albumin (BSA)-labeled, alkaline phosphatase-entrapped liposomes in the presence of anti-BSA rabbit serum and active complement under alkaline conditions. Sensitive detection is possible because of the antigen-antibody complex reaction, which leads to liposome lysis and an enzymatic reaction. The liposome immunoassay method offers a rapid, simple, and sensitive testing procedure which can quantitatively and qualitatively determine the presence or absence of antigenic materials and antibodies.

Epidemiological characteristics of ketoacidosis among Korean diabetic patients

An epidemiological study on diabetic ketoacidosis (DKA) was done by analysis of 207 cases collected from the medical records of 6 major general hospitals in Seoul area during the period of 5 years between 1979 and 1984. There was female predominance in the occurrence of DKA (male/female ratio, 0.71) in spite of the male predominance in general prevalence of diabetes mellitus (1.80). This female predominance in DKA was most striking in the age group under 40. There was a significant seasonal variation in the occurrence of DKA. DKA occurred most frequently in colder season with the highest peak in December. In July and August, the hottest season in Korea, not even a single case of DKA was recorded in this series. No discernible precipitating factor was found in 39.3% of DKA cases and infections was present as a cause of DKA in 30% of cases. In 27.5%, DKA was the first clinical presentation of diabetes and in the remainders of cases, diabetes was known to be present for average of 6.4 years. Mortality of DKA was 13.2% in this series. As to the socioeconomic status, the education level, the style of living and the duration of diabetes, there were not ascertainable differences between the DKA cases and other diabetic cases. The prospective epidemiological study of diabetic population in Korea, especially in female group, would be necessary for elucidation of the characteristics of DKA in Koreans such as the female predominance and the seasonal difference of the occurrence.

Studies on changes of beta-adrenergic receptors in polymorphonuclear cell and mononuclear cell with the changes of thyroid function

Although it has been well established that thyroid hormones increase β-adrenergic receptors of various tissues in the animal studies, there are controversies about the β-adrenergic receptor changes of human mononuclear cells and polymorphonuclear cells. The present study was performed to analyze the change of β-adrenergic receptor of those cells according to the thyroid functional status and to evaluate their usefulness in assessment of sympathetic hyperactivity. We measured [³H]-dihydroalprenolol binding to circulating mononuclear and polymorphonuclear cells from 18 patients with hyperthyrodism, 7 with hypothyroidism, 8 with euthyroid goiter and 21 normal controls. Only with polymorphonuclear cells the receptor concentration was significantly higher (P<0.01) in hyperthyroidism (46.07±4.78 fmol/mg protein) than in the normal control (28.42±2.06 fmol/mg protein) and the affinity constants of both cells were comparable to normal control values. And serum concentrations of T₃ were not correlated well with the changes of receptor concentrations in hyperthyroidism. The patients with hypothyroidism and euthyroid goiter showed no significant difference in the receptor concentration and the affinity constants with both cell binding assays. These results indicate that thyroid hormones increase the receptor concentration in polymorphonuclear cells which might be responsible for the symptoms of sympathetic hyperactivity and the polymorphornuclear cells are useful for β-adrenergic receptor assay.

Postprandial 2-hr C-peptide concentration as a guide for insulin treatment in patient with NIDDM

To determine the usefulness of postpradial-2hr serum C-peptide as a guide for insulin treatment in NIDDM, the 67 NIDDM patients admitted in Kyung Hee University Hospital from Nov. 1981 to May 1984 were classified according to postprandial 2-hr insulin, C-peptide levels and 24-hr urine C-peptide levels. The patients were divided into 3 groups according to the level of insulin or C-peptide in normal persons reported previously. In 22 patients with postprandial 2-hr values of more than 5.8 ng/ml for C-peptide, 12 patients (55%) were diet controllable and only 5 patients (22%) required insulin treatment. On the other hand, in the classification according to postprandial 2-hr insulin or 24-hr urine C-peptide levels, higher response groups should be controlled by diet alone, but 9 of 18 patients (50%) for insulin, 8 of 14 patients (57%) for 24-hr urine C-peptide required insulin treatment. The classification according to postprandial 2hr C-peptide levels was a more sensitive guide for insulin treatment than that with postprandial 2hr insulin level or 24hr urine C-peptide level.

The changes of serum-ACE, plasma renin activity and aldosterone in the diabetics with hypertension

It is well known that the serum-ACE levels are elevated in sarcoidosis, Gaucher’s disease, and some granulomatous diseases. Recently, the serum-ACE level was also found to be elevated in diabetes mellitus. To confirm the possible role of plasma renin activity and aldosterone in the pathogenesis of hypertension and to assess the relationship of serum ACE to the plasma renin activity and aldosterone profiles in diabetics, we measured the levels of serum ACE, plasma renin activity, aldosterone and blood pressure in 38 diabetic patients who were admitted to Kyung Hee University Hospital from June 1981 to September, 1982. The results were as follows: The S-ACE activity was significantly elevated in 38 patients with diabetes mellitus (9.42±6.60 Unit) as compared with that in the healthy controls (2.53±1.54 Unit) (p<0.005) (p<0.005). The S-ACE activity was significantly elevated in 15 hypertensive diabetics (14.29± 7.10 Unit) as compared with that in 23 normotensive diabetics (6.24±3.68 Unit) (p<0.005). The S-ACE activity was elevated in 15 diabetic patients with retinopathy (10.6±4.7 Unit) as compared with the levels in 17 diabetic patients without retinopathy (6.7±4.8 U) (p<0.05). The S-ACE activity was directly correlated to the mean arterial pressure (r=0.54) (p<0.005). The plasma renin activity and aldosternone concentrations in diabetics were not different from the normal controls and had no correlationship to the S-ACE activity. After 2 weeks of insulin therapy in 15 diabetics, the S-ACE activity was not changed.

Effect of beta-endorphin and cortisol on the PHA stimulated lymphoblastogenesis

The mechanism of immune suppression in a severely stressful condition is not known. Since the demonstration of β-endorphin receptor on the surface of the circulating lymphocyte, it was reported that β-endorphin could suppress PHA stimulated lymphoblastogenesis. Because the concentration of β-endorphin was supraphysiologically high, it is doubtful that β-endorphin can suppress the lymphoblastogenesis directly in vivo. We investigated the suppression of PHA stimulated lymphoblastogenesis by β-endorphin in vitro and the effect of β-endorphin in some conditions where β-endorphin increases in vivo. PHA induced lymphoblastogenesis of T lymphocyte was maximal at the concentration of 5 μg/ml. β-endorphin could not suppress the blastogenesis even at the highest concentration. In the five healthy men who received metyrapone the previous night, PHA stimulated blastogeneses were not significantly suppressed. In a patient with Nelson’s syndrome, the lymphoblastogenesis was suppressed at all concentrations of PHA. Cortisol significant suppressed the blastogenesis even at the concentration of 10 μg/dl and its suppressive effect was shown in dose dependant manner. Our results suggested that β-endorphin could not suppress the lymphoblastogenesis directly in vivo.