[Autonomic neuropathy in diabetics--autonomic function and plasma catecholamines]

Autonomic neuropathy is one of the complications of diabetes. Recently, several authors reported that measuring R-R interval variation of ECG is a noninvasive and useful method for testing parasympathetic function. However, there were few reports about sympathetic function in diabetics. In order to evaluate sympathetic function in diabetics quantitatively, we studied the responses of plasma norepinephrine (NE), epinephrine (E) and related factors after 60 min bed rest and sequentially during 10 min of upright posture and 5 min handgrip while still upright. We also studied the responses of NE and E during 5 min smoking in supine position. Subjects were divided into four age-matched groups. These were 15 normal subjects (Group I), 20 diabetics without complications (Group II), 20 diabetics with peripheral neuropathy but no autonomic symptoms (Group III) and 15 diabetics with autonomic symptoms (Group IV). We also studied R-R interval variation (CV: Coefficient of Variation) as a parameter of parasympathetic function and compared this with sympathetic function. Upon standing, blood pressure (BP) dropped precipitously in Group IV, whereas no significant changes were observed in the other three groups. Heart rate (HR) increased in Groups I and II, but not in Groups III and IV. During handgrip, BP and HR did not change significantly in all groups. Basal NE levels in Group IV were significantly smaller than those in Group I. NE responses to both standing and handgrip stimuli were markedly reduced in Group IV and, even in Group III, increments were significantly smaller than those in Groups I and II. Basal E levels did not differ, and significant changes were not observed after standing and handgrip in all groups. Both plasma renin activity (PRA) and plasma aldosterone concentrations (PAC) in Groups III and IV were lower than those in Groups I and II at rest and standing. After smoking, both BP and HR increased significantly in Groups I, II and III, whereas no changes were observed in Group IV. Both NE and E responses were markedly reduced in Group IV and, even in Group III, responses were significantly smaller than those in Groups I and II. CV in Groups III and IV were significantly smaller than those in Groups I and II. In diabetics, CV was strongly correlated with NE increments after standing (r = 0.78, p less than 0.01). Also, CV was correlated with both NE and E increments after smoking (r = 0.71 (NE), r = 0.82 (E), p less than 0.01).(ABSTRACT TRUNCATED AT 400 WORDS)

Role of macrophages in serum colony-stimulating factor induction by Lactobacillus casei in mice

Heat-killed Lactobacillus casei YIT9018 (LC9018), when injected intravenously into mice at a dose of 4 to 40 mg/kg, induced the production of serum colony-stimulating factor (CSF). Since this induction was observed in both C3H/HeJ and C3H/HeN mice, LC9018 was considered to act differently from lipopolysaccharide. The amount of serum CSF induced by LC9018 in nude mice and whole-body-X-ray-irradiated mice was similar to that in control mice, but the induction of serum CSF was suppressed by the previous administration of carrageenan, indicating that macrophages, but not T cells, were responsible for serum CSF induction by LC9018. To determine whether macrophages themselves produce CSF or help other cells produce CSF in response to LC9018, we prepared adherent cells from the peritoneal cavity of normal mice and examined CSF activity in their conditioned media. Peritoneal adherent cells did not produce CSF without LC9018, but when cultivated with 1 mg of LC9018 per ml, they produced CSF at the same time that serum CSF was induced after the intravenous administration of LC9018. Additionally, in vitro-induced CSF formed macrophage, granulocyte, and mixed colonies, as serum CSF did. CSF production by peritoneal adherent cells was completely inhibited by cycloheximide (50 micrograms/ml), and neither the elimination of T cells from the peritoneal adherent cells by treating them with anti-Thy-1.2 antibody plus complement nor the addition of T cells affected CSF production. These results suggest that heat-killed LC9018 induces serum CSF in mice via direct stimulation of macrophages to produce CSF de novo.

Atrial natriuretic peptide and vasopressin in human plasma

Using a specific radioimmunoassay for atrial natriuretic peptide (ANP), plasma immunoreactive ANP was measured in 17 normal subjects and 83 patients with various diseases. Plasma ANP concentration in normal subjects was 14.1 +/- 1.7 pg/ml (mean +/- S.E.). Relatively high plasma ANP concentrations were detected in patients with diabetes mellitus, hyperthyroidism, atrial fibrillation and liver cirrhosis. Plasma ANP concentrations in the patients correlated positively with mean arterial blood pressure and plasma AVP concentrations. Plasma ANP concentrations in the patients also had positive correlations with left atrial dimension and left ventricular diastolic dimension determined by echocardiography. Another positive correlation was observed in the patients between plasma AVP concentrations and mean arterial blood pressure. These results suggest that ANP is a volume regulatory hormone but also that ANP may be involved in the blood pressure regulating system.

[Studies on cytosol thyroid hormone binding proteins in the rat liver: Part I. Stability and binding characteristics of thyroid hormone binding proteins]

Many studies demonstrated the presence of cytosolic thyroid hormone binding proteins (CTHBPs) in various tissues, but the physiologic significance of these CTHBPs is not clear, partially because of the lack of information about the physicochemical properties of CTHBPs as purified forms. Since the difficulty in isolating these CTHBPs is considered to be due to instability during the various procedures for their isolation, studies on the stability of CTHBPs of rat liver were performed using a charcoal binding method to separate bound and free hormones. Binding characteristics of CTHBPs of rat liver were also determined. Specific triiodothyronine (T3) binding sites of cytosolic T3 binding protein (CT3BP) of rat liver were destroyed as the time progressed in homogenate at 0 degrees C, and Aprotinin (500 U/ml) had little effect in protecting these binding sites. T3 binding sites were stable in the form of cytosol at -20 degrees C up to 10 weeks. Dithiothreitol (DTT) had no effect on T3 binding to cytosol. T3 binding to CT3BP was pH-dependent with maximum specific binding at pH 7.4. T3 binding to CT3BP was stable at 4 degrees C overnight but was destroyed rapidly at 37 degrees C. Interestingly, specific T3 binding sites of CT3BP were completely abolished by dialysis, and Ca2+ or Mg2+ had no effect on retaining the specific binding sites. Thus, CT3BP was supposed to require some dialysable small molecule(s) to maintain specific T3 binding sites. Scatchard plot of T3 binding to crude cytosol revealed a high affinity, limited capacity T3 binding site with affinity constant (Ka) of 5.9 X 10(7) M-1 and maximum binding capacity (MBC) of 118 ng/g. liver. Relative affinities of T3 analogues for CT3BP were determined by comparing the molar concentrations of T3 analogues required for 50% inhibition of tracer 125I-T3 binding. If the affinity of L-T3 was assigned 100, D-T3 would have a value of 66.1; L-T4, 22.3; D-T4, 16.5; Triac, 6.2; and both Tetrac and reverse T3 were less than 1. Thus, the binding characteristics of CT3BP were fundamentally different from those of nuclear T3 receptor. Cytosolic thyroxine (T4) binding protein (CT4BP) of rat liver was relatively stable compared with CT3BP in homogenate at 0 degrees C. CT4BP was also stable in the form of cytosol at -20 degrees C for 10 weeks. CT4BP was pH-dependent with maximum specific binding at pH 7.4. It was stable at 4 degrees C overnight but destroyed rapidly at 37 degrees C. Specific T4 binding was decreased by dialysis but not abolished completely.(ABSTRACT TRUNCATED AT 400 WORDS)

[Studies on cytosol thyroid hormone binding proteins in the rat liver: Part III. Partial purification and binding characteristics of thyroxine-binding protein in hypothyroid rat liver cytosol and serum]

Cytosolic thyroxine-binding protein (CT4BP) was partially purified from rat liver cytosol obtained 10 days after thyroidectomy using Sephadex G-200 gel filtration, and its binding characteristics were analyzed in displacement experiments using a charcoal binding method to separate bound and free hormones. Serum T4-binding proteins were also partially purified, and their binding characteristics were similarly determined. Sephadex G-200 gel filtration of liver cytosol from thyroidectomized rats revealed that CT4BP had an apparent molecular weight of 100 X 10(3) daltons. CT4BP had a very high affinity constant (Ka) of 2.2 +/- 10(10) M-1 and a small maximum binding capacity (MBC) of 5.1 X 10(-9) g/mg. protein for T4. Relative affinities of T4 analogues for CT4BP (if the affinity of L-T4 was assigned a value of 100, then D-T4 would have a value of 25.3; L-T3, 16.6; D-T3, 2.3; reverse T3, 1.4 and both Tetrac and Triac less than 1) showed that CT4BP had a rigid specificity for alanine-side chain of T4-molecule. This CT4BP was not demonstrated when cytosol from normal rat liver was used. Sephadex G-200 gel filtration of rat serum obtained 10 days after thyroidectomy revealed two T4-binding proteins. The faster peak (Peak I; MW about 100 X 10(3) daltons) was eluted before the albumin peak, and the slower peak (Peak II; MW about 56 X 10(3) daltons) appeared after the albumin peak. Peak I was barely detectable when normal rat serum was used. Peak I had a higher Ka of 2.0 X 10(10) M-1 and a smaller MBC of 3.9 X 10(-9) g/mg. protein than Peak II (Ka; 8.9 X 10(8) M-1, MBC; 3.7 +/- 10(-7) g/mg. protein). Relative affinities of T4 analogues for Peak I (L-T4 100, D-T4, 34.9, L-T3 11.1, D-T3 1.8, reverse T3 6.8, Tetrac 0.25 and Triac 0.1) showed that Peak I had a rigid specificity to alanine-side chain of T4 molecule, but Peak II had little specificity to this side chain (L-T4 100, D-T4 9.2, L-T3 2.1, D-T3 1.0, reverse T3 14.3, Tetrac 69 and Triac 26.3). Thus, Peak I had a similar binding characteristics to those of human thyroxine-binding globulin (TBG), and Peak II was comparable to human thyroxine-binding prealbumin (TBPA). The results that both molecular weight and binding characteristics were similar between CT4BP and Peak I suggest that both proteins are identical, being comparable to human TBG. This must be clarified in future.

[Studies on cytosol thyroid hormone binding proteins in the rat liver: Part II. Alterations of thyroid hormone binding proteins in various thyroid function states]

Alterations of binding characteristics of cytosolic thyroid hormone binding proteins (CTHBPs) were examined in livers of rats with different thyroid function. Seven days after thyroidectomy, rats were divided into three groups. Group I received no treatment. Group II was treated with 230 ng triiodothyronine (T3)/100 g body weight per day for three days, and Group III with 40 micrograms T3/100 g body weight per day for three days. On the fourth day, each rat was given 0.7 microCi of 125I-T3/100 g body weight intraperitoneally and exsanguinated two hours later. During three days' treatment, body weight in Group II increased significantly compared with that in Group I (P less than 0.05), and body weight in Group III actually decreased. The ratio of liver weight to body weight in Group II was significantly higher than that in Group I or Group III (P less than 0.01). Percent distributions of 125I-T3 in cytosol fraction per liver or concentrations of cytosolic protein did not differ significantly among these three groups. Serum T3 concentrations (mean +/- SD ng/ml: Group I; not detectable, Group II; 0.50 +/- 0.27, Group III; 7.10 +/- 2.31), cytosolic T3 concentrations (mean +/- SD ng/ml: Group I; not detectable, Group II; 0.59 +/- 0.26, Group III; 10.38 +/- 3.08) and mitochondrial alpha-glycerophosphate dehydrogenase activities (mean +/- SD delta OD500 millimicrons/min/mg: Group I; 28.0 +/- 1.5, Group II; 46.7 +/- 7.3, Group III; 267.7 +/- 9.1) suggested that Group I was in hypothyroid state, Group II in euthyroid state and Group III in thyrotoxic state. Binding characteristics of cytosolic T3 binding protein (CT3BP) were different among the three groups.(ABSTRACT TRUNCATED AT 400 WORDS)

Mutagenic activation of biliary metabolites of benzo(a)pyrene by beta-glucuronidase-positive bacteria in human faeces

Human faeces hydrolysed synthetic beta-D-glucuronides of both p-nitrophenol and phenolphthalein. The origin of this activity in faeces was localised in the bacterial pellet fraction after centrifugation. Ninety-seven bacterial strains with beta-glucuronidase activity isolated from fresh human faeces were identified as species of Bacteroides, Peptostreptococcus, Fusobacterium, Propionibacterium, Clostridium, Eubacterium and Bifidobacterium. They were classified into two groups according to their activity against two synthetic beta-D-glucuronides. One group hydrolysed p-nitrophenyl glucuronide and phenolphthalein glucuronide to the same extent and the other hydrolysed p-nitrophenyl glucuronide much more strongly than phenolphthalein glucuronide. The bile of rats given benzo(a)pyrene by mouth was tested for mutagenicity in the presence and absence of cell-free extracts of human faeces and bacteria. Extracts of beta-glucuronidase-positive bacteria increased the mutagenicity of metabolites of benzo(a)pyrene, as did faecal extracts, but extracts of beta-glucuronidase-negative bacteria did not. D-Saccharic acid-1,4-lactone inhibited the increase in mutagenicity produced by the faecal extracts and extracts of beta-glucuronidase-positive bacteria except for Peptostreptococcus strains 204 and 952. These results indicate that some intestinal bacteria have beta-glucuronidases heterogenous in substrate specificity and that they may be involved in mutagenicity of benzo(a)pyrene in the intestinal tract.

Induction by Lactobacillus casei of increase in macrophage colony-forming cells and serum colony-stimulating activity in mice

The content of macrophage colony-forming cells (M-CFC) and the serum colony-stimulating activity (CSA) were investigated in mice after intravenous administration of Lactobacillus casei YIT9018 (LC9018). In normal BALB/c mice, 500 micrograms of LC9018 increased both femoral and splenic M-CFC; the highest levels were found a few days and a week, respectively, after the administration. LC9018 also induced an increase in splenic M-CFC in C3H/HeJ mice as well as in C3H/HeN mice, unlike lipopolysaccharide (LPS), which was ineffective in C3H/HeJ mice. In Meth A-bearing BALB/c mice, LC9018 (250 micrograms X 5) suppressed the growth of tumor cells and increased femoral and splenic M-CFC to much greater extents than Lactobacillus plantarum YIT0102 (250 micrograms X 5) did. LC9018 induced a rise of serum granulocyte-macrophage CSA in the same way as LPS. Sera taken 6 hr after LPS administration, when transferred to normal mice, induced increases in femoral and splenic M-CFC. However, sera taken 6 hr after LC9018 administration increased neither femoral nor splenic M-CFC. These results indicate that LC9018 modulates myelopoiesis at least at the stage of the proliferation of M-CFC in a different way from LPS, and this ability may be related to its antitumor activity.

Mutagenic activation of biliary metabolites of 1-nitropyrene by intestinal microflora

To investigate the modifying role of intestinal microflora in the metabolism of chemical carcinogens in vivo, we subjected bile from Fischer rats treated per os with chemical carcinogens and related compounds to a mutagenicity assay in the presence and absence of a cell-free extract from human feces. A mixture of the bile sample and potassium phosphate buffer was incubated in the presence or absence of human cell-free fecal extract and then further incubated with a bacterial suspension of Salmonella typhimurium tester strains TA98 or TA100. Bile from rats treated with 1-nitropyrene (1-NP) produced about 2700 and 400 revertants per plate in strain TA98 in the presence and absence of the fecal extract, respectively. There was a drug dose- and bile volume-related response. Treatment of 1-NP-bile with beta-glucuronidase, but not aryl sulfatase, enhanced its mutagenicity. Cell-free extracts of some strains of intestinal bacteria (Bacteroides fragilis ATCC 12044, B. vulgatus ATCC 8482, B. thetaiotaomicron ATCC 12290, Bacteroides sp. strain 524, Eubacterium eligens VPI C15-48, Peptostreptococcus sp. strain 204 and Escherichia coli A-5-18) also enhanced the mutagenicity of 1-NP-bile. These bacterial cell-free extracts hydrolyzed the synthetic beta-D-glucuronides of phenolphthalein and/or p-nitrophenol. These data indicate that the glucuronide(s) of 1-NP-metabolite(s) secreted into bile can be hydrolyzed in the intestine by bacterial beta-glucuronidases to potent mutagenic aglycone(s).

Tri-iodothyronine-induced increase in rat liver nuclear thyroid-hormone receptors associated with increased mitochondrial alpha-glycerophosphate dehydrogenase activity

The effect of tri-iodothyronine injection on the nuclear tri-iodothyronine receptor (putative thyroid-hormone receptor) was examined in rat liver. Nuclear receptors were extracted from isolated nuclei with 0.4 M-KCl, and their association constants (Ka) and maximal binding capacities (Cmax.) were determined by Scatchard analyses with and without correction for the endogenous hormone. The amount of endogenous tri-iodothyronine bound to non-histone protein was estimated on the basis of the specific radio-activity of [125I]tri-iodothyronine injected 2 h before the rats were killed. It was demonstrated that Cmax. of the nuclear receptors was 2.5-fold higher in severely hyperthyroid than in hypothyroid rats. However, irrespective of the thyroid status, the Ka of the receptors remained unchanged when corrected for endogenous tri-iodothyronine bound to non-histone protein. The validity of the correction was supported by experiments in vitro in which nuclear receptors were preincubated with unlabelled tri-iodothyronine. The increase in Cmax. of nuclear receptors was directly related to mitochondrial alpha-glycerophosphate dehydrogenase activity. These results suggest a hormonal modulation of the nuclear receptors which is associated with hormonal action.

Inhibition of angiotensin III action by DES-ASP1-,ILEU8-angiotensin II in man

In 5 normal men intravenous infusion of 600 ng/kg/min of des-asp1-ileu8-angiotensin II (AIIIA) inhibited a rise in blood pressure as well as increase in plasma aldosterone caused by an intravenous infusion of 20 or 100 ng/kg/min of des-asp1-angiotensin II (angiotensin III, AIII). This result and our previous study on simultaneous infusions of 600 ng/kg/min of AIIIA and 20 ng/kg/min of angiotensin II (AII) in the same 5 normal men demonstrate that this dose of AIIIA antagonizes AIII and AII on the adrenal cortex as well as peripheral arterioles and that AIIIA has the same degree of inhibitory effect on the aldosterone-stimulating action of AIII and on that of AII in man.

Hypothalamo-pituitary-adrenal function in pituitary adenoma and craniopharyngioma. Part I: Insulin test, lysine-vasopressin test, and rapid ACTH test

For the assessment of hypothalamo-pituitary-adrenal function in the presence of pituitary adenomas and craniopharyngiomas, insulin tests, lysine-vasopressin tests, and rapid ACTH tests were performed and plasma cortisol was assayed. Rapid ACTH test and lysine-vasopressin test, which examine adrenal and mainly pituitary function respectively, showed normal function in ten among 14 cases. But insulin test, which examines the whole hypothalamo-pituitary-adrenal function, showed various levels of abnormality in eight among 14 cases. Frequent association of functional disturbances of this axis in these diseases was stressed.

Hypothalamo-pituitary-adrenal function in pituitary adenoma and craniopharyngioma. Part II: insulin test and clinical features

For the assessment of hypothalamic corticotropin releasing hormone (CRH) secretory function, insulin test, lysinevasopressin test, and rapid ACTH test were performed and plasma crotisol was assayed. Disturbances of CRH secretory activities were found not to be related with the degree of suprasellar extension of tumors, contents of tumors, the degree of visual disturbances, or the duration of symptoms, and it was supposed that more complex mechanisms were responsible for CRH secretory abnormalities.

Ultracentrifugal characterization of cytosol-binding proteins for thyroxine and triiodothyronine in human liver

Sucrose density gradient ultracentrifugation was performed on human liver cytosol containing double tracers of 131I-thyroxine(T4) and 125I-triiodothyronine(T3) together with or without large amount of stable hormones. Tracer T4 bound to the cytosol indicated 2 peaks of 8.3S and 4.7S, both of which were displaced with stable T4, but not with T3. Maximal binding capacity of the 8.3S component averaged 43.2 microgram/100ml of 33% cytosol. Tracer T3 in the cytosol showed a single peak of 4.2S which was displaced with stable T3 and also with T4. The results indicate thtat the human liver cytosol contains limited-capacity binding proteins: the one specific for T4, and the other relatively specific for T3.

Biological activity of high dose of des-asp 1-, ileu 8-angiotensin II in man

The biological activity of high doses of des-asp 1-, ileu 8-angiotensin II (AIIIA) was studied in man. In 5 normal men an intravenous infusion of 600 ng/kg/min of AIIIA for 30 min caused a slight rise in blood pressure, a decrease in plasma renin activity and an increase in plasma aldosterone. This dose inhibited pressor and steroidogenic actions of angiotensin II infused into the same 5 normal men at a rate of 20 ng/kg/min for 30 min. These results are considerably different from our previous report using lower dose (200 ng/kg/min) of AIIIA and indicate that in man AIIIA has both agonist and antagonist activities on the peripheral arterioles as well as on the adrenal cortex.

Biological activity of des-Asp1-,Ileu8-angiotensin II (Ileu8-angiotensin III) in man

Biological activity of ileu8-angiotensin III (AIIIA) was studied in man. In 5 normal men intravenous infusion of 200 ng/kg/min of AIIIA for 30 minutes from 0900 h had no effect on blood pressure (BP) but caused a decrease in plasma renin activity (PRA) and an increase in plasma aldosterone (PA). This dose did not inhibit pressor and steroidogenic actions of angiotensin II (AII) infused into the normal men at a rate of 20 ng/kg/min for 30 minutes. In 3 patients with Bartter's syndrome 260-1,200 ng/kg/ min of AIIIA infusion for 30 minutes from 0900 h had no effect on BP but caused decreases in PRA and PA. These results indicate that in man AIIIA has no pressor action and no antagonistic effect on pressor action of AII but has PRA-lowering and aldosterone-stimulating effects. Antagonistic effect of AIIIA on steroidogenic action of AII was also shown in patients with Bartter's syndrome but not in AII-treated normal men. This may be due to the difference of administered dose of AIIIA.

Blood pressure fall by angiotensin II antagonist in patients with Bartter's syndrome

Intravenous infusion of 600 ng/kg/min of 1-sarcosine, 8-isoleucine-angiotensin II, an angiotensin II antagonist, caused a marked blood pressure fall and a decrease in plasma aldosterone in 3 patients with Bartter's syndrome. These results indicate that proximal cause of Bartter's syndrome is an arteriolar hyporesponsiveness to angiotensin II and that this angiotensin II analogue has an antagonist activity on peripheral arterioles as well as adrenal cortex.

Biological activity of des-asp1-angiotensin II (angiotensin III) in man

Effects of des-asp1-angiotensin II (angiotensin III) on blood pressure and aldosterone secretion were examined in man. Angiotensin III was equipotent with val5-angiotensin II amide in the stimulation of aldosterone production, but had only 20% of the pressor activity of the later. These results are consistent with those previously reported by other investigators in animals.