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E Haug

Publications and source records attributed to E Haug.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effects on the endocrine system of long-term treatment with the non-steroidal anti-androgen Casodex in patients with benign prostatic hyperplasia.

OBJECTIVE: To study the hormonal changes resulting from long-term use of the non-steroidal anti-androgen Casodex. PATIENTS AND METHODS: A randomized, placebo-controlled study was carried out on 27 patients with benign prostatic hyperplasia (BPH). Fourteen patients received Casodex 50 mg daily for 24 weeks and 13 received a placebo. The patients were followed up for a further 24-week period. RESULTS: Serum concentrations of luteinizing hormone (LH) increased by an average of 40% while follicle-stimulating hormone (FSH) remained unchanged. Testosterone increased by 35%, oestradiol by 29% and oestrone by 23%; all changes were statistically significant. Levels of androstenedione and dihydrotestosterone increased by 11% and 15%, respectively, but these increases did not reach statistical significance. A non-significant increase was also observed for sex hormone-binding globulin. The hormonal changes were reversible upon discontinuation of therapy. Prolactin and dehydroepiandrosterone-sulphate levels did not change. CONCLUSION: This study indicates that Casodex, due to competitive inhibition of central androgen receptors, increases LH secretion, thus causing increased production and increased metabolism of testosterone.

Aged↗
PubMed1995

Congestive heart failure caused by vitamin D deficiency?

We describe a child, 3.5 months old, with severe vitamin D deficiency, profound hypocalcaemia, hyperphosphataemia, dilated left ventricle, severely reduced myocardial contractility and congestive heart failure. She also had depressed thyroid function with subnormal thyroxine and non-detectable serum thyrotropin (TSH) levels. The child promptly responded to calcium infusions, conventional anticongestive therapy and calcitriol. She is now 3 years old and received no medication. Myocardial function is normal but she has motor delay. We believe that her transitory congestive heart failure was caused by severe vitamin D deficiency with profound hypocalcaemia.

Calcitriol↗
PubMed1995

Toxin of the marine alga Prymnesium patelliferum enhances voltage dependent Ca(2+)-currents, elevates the cytosolic Ca(2+)-concentration and facilitates hormone release in clonal rat pituitary cells.

The marine flagellate Prymnesium patelliferum produces toxins lethal to fish. The toxin extracted from the alga has haemolytic, cytotoxic and neurotoxic effects, but the action mechanisms of the toxin are not known in detail. We have examined the toxin effects on the voltage sensitive Ca(2+)-currents, the cytosolic Ca(2+)-level ([Ca2+]i) and the prolactin release in clonal rat anterior pituitary GH4C1 cells, which possess T- and L-type Ca(2+)-channels. The trans-membrane Ca(2+)-current was recorded using whole-cell voltage clamp. After 5-15 min exposure to the algal toxin at a final concentration of 50,000-100,000 cells mL-1, the Ca(2+)-currents through both the T- and L-channels showed a 2-3-fold enhancement. The voltage sensitivity of the Ca(2+)-currents was not affected by the algal toxin, and the toxin-induced currents were inhibited by 100 microM of the Ca(2+)-channel blocker D-600. In toxin-exposed cells microfluorometric measurements based on fura-2 revealed an increase of [Ca2+]i from 100-150 to 300-500 nM. This elevation was delayed and partially inhibited by 100 microM D-600. The algal toxin induced prolactin release in a dose-dependent manner, and this effect was inhibited by the Ca(2+)-channel blocker verapamil. We therefore conclude that the toxin of P. patelliferum affects the Ca2+ homeostasis of the pituitary cells by increasing the leak through voltage sensitive Ca(2+)-channels, resulting in increased [Ca2+]i and secretion of prolactin.

Animals↗
PubMed1995

Oral intake of selenium has no effect on the serum concentrations of growth hormone, insulin-like growth factor-1, insulin-like growth factor-binding proteins 1 and 3 in healthy women.

The administration of large doses of selenium (Se) to rats leads to reduced serum levels of somatotropin (growth hormone) and insulin-like growth factor-1 (IGF-1), followed by growth retardation. Similar experiments in humans have been contradictory. The effects of wheat Se and selenomethionine supplementation were investigated in healthy, Norwegian women. In study 1, the participants (n = 18) were given Se-rich bread with 100, 200 and 300 micrograms Se daily for 6 weeks. Initial serum Se concentration were 1.5 +/- 0.2 mumol/l (mean +/- SD). Serum Se increased in a dose-dependent manner in the three groups (p < 0.001). There was no effect on somatotropin and IGF-1 at any of the Se doses given. In study 2 (n = 24), the effects of 400 micrograms selenomethionine daily for 15 weeks were studied in a placebo controlled study. In the treatment group, serum Se concentrations increased by more than 100%. There was, however, no effect on serum somatotropin and IGF-1 concentrations, nor was there any effect on IGF-binding proteins 1 and 3. Our results indicate that at normal or slightly increased intakes, Se has no effect on the serum concentrations of these two hormones in healthy individuals.

Adult↗
PubMed1995

Inappropriately low levels of gonadotrophins in amenorrhoeic women with alcoholic and non-alcoholic cirrhosis.

We investigated a group of 111 amenorrhoeic females with associated liver disease. These comprised alcoholic cirrhotics (N = 38), non-alcoholic cirrhotics (N = 12), non-cirrhotic alcoholics (N = 21) and those suffering from other chronic liver diseases (N = 40) admitted to our medical department from 1986 to 1991. The serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), oestradiol, testosterone, sex hormone binding globulin (SHBG) and prolactin were measured. Serum LH was decreased below the normal range in 50% of patients with alcoholic cirrhosis and in 42% of patients with non-alcoholic cirrhosis. One third of non-cirrhotic alcoholics also had decreased LH, in contrast to only 8% of patients with other chronic liver diseases (p < 0.01). A close correlation was found between LH and FSH when all patients were pooled (r = 0.91, p < 0.001). A gonadotrophin-releasing hormone (GnRH) injection elicited a clear LH and FSH response in 11 out of 14 patients with cirrhosis, indicating that the hypothalamus rather than the pituitary is the site of disturbance in gonadotrophin secretion. Serum SHBG was within normal limits and similar in all four groups. In nine females with alcoholic cirrhosis who abstained for 3 months, serum SHBG increased significantly from 39 +/- 18 to 70 +/- 25 nmol/l (p < 0.001), while LH increased in five of nine females and was unchanged in four. In conclusion, half of the amenorrhoeic females with alcoholic as well as non-alcoholic cirrhosis had inappropriately low serum LH and FSH levels, indicating dysfunction of the hypothalamo-pituitary axis.(ABSTRACT TRUNCATED AT 250 WORDS)

Amenorrhea↗
PubMed1995

Endocrine and metabolic characteristics of polyoma large T transgenic mice that develop ACTH-producing pituitary tumors.

The authors have analyzed several endocrine and metabolic parameters in polyoma large T transgenic mice (PyLT-1) that develop adrenocorticotropic hormone (ACTH)-immunoreactive pituitary tumors and in nontransgenic mice with tumor transplants. All clinically ill PyLT-1 mice (13 to 16 months of age) had pituitary macroadenomas and elevated plasma ACTH levels. Compared to PyLT-1 transgenic mice, the ACTH plasma concentrations in immunocompetent mice with transplant tumors were markedly raised. In these animals, a secondary effect of hypercorticotropism was documented by a moderate hyperglycemia. Furthermore, mice with transplant tumors had a pathological weight increase from the time the tumor was palpable. The present study supports and extends the authors' previous morphological documentation of the similarity between the ACTH-producing tumors in this mouse model and human Cushing's disease.

Adrenocorticotropic Hormone↗
PubMed1995

[Vitamin D and osteoporosis].

Vitamin D constitutes a complex endocrine-regulated system, and is both a prohormone for the endogenous synthesis of the active hormone, calcitriol, and a vitamin which may be administered to supply the organism's requirements. No single test or investigation is available for the demonstration of vitamin D deficiency. Both vitamin D intake and ability to synthesise vitamin D decrease with increasing age, and particularly the elderly in institutionalised care are at risk of developing vitamin D deficiency. Iceland excepted, mean daily vitamin D consumption in the Nordic countries is less then 5 micrograms; and in approximately 10-25 per cent of the population, daily intake is less than 2.5 micrograms which is insufficient to maintain an adequate serum calcidiol concentration in individuals unexposed to sunlight. The recommended daily intake of 5 micrograms, currently adopted in the Nordic countries, may be too low-an intake of 10 micrograms is probably necessary to satisfy requirements in the elderly.

Adrenal Cortex Hormones↗
PubMed1995

Dopaminergic inhibition of pulsatile luteinizing hormone secretion is abnormal in regularly menstruating women with insulin-dependent diabetes mellitus.

OBJECTIVE: To examine the influence of low doses of dopamine (DA) (0.4 micrograms/kg per minute), on the secretion pattern of LH. DESIGN: Prospective randomized, single blind, placebo-controlled crossover study with infusion of DA or placebo in the follicular phase in regularly menstruating women with insulin-dependent diabetic mellitus (IDDM) and controls during 9.5 hours. SETTING: Department of Endocrinology, Odense University Hospital, Odense, Denmark. PATIENTS: Eight regularly menstruating IDDM women and eight controls. MAIN OUTCOME MEASURES: Mean LH, LH pulse amplitude, and LH pulse frequency. RESULTS: During placebo infusion no significant differences in basal LH values, pulse amplitude, and pulse frequency were seen between IDDM women and controls. In diabetics, basal LH levels and pulse amplitude decreased significantly during DA infusion (3.1 +/- 1.2 mIU/mL (conversion factor to SI unit, 1.00; mean +/- SD) and 0.9 +/- 0.3 mIU/mL, respectively) compared with placebo (4.5 +/- 1.1 and 1.2 +/- 0.4 mIU/mL, respectively). In normal women no significant changes were observed (basal LH 3.0 +/- 1.8 versus 3.2 +/- 1.6 mIU/mL and pulse amplitude 1.6 +/- 0.6 versus 1.5 +/- 0.9 mIU/mL). The LH pulse frequency during DA infusion was not different from placebo in either normal (9.0 +/- 2.7 versus 10.3 +/- 4.0) or diabetic women (11.8 +/- 2.1 versus 10.9 +/- 1.8). CONCLUSION: These results suggest that diabetic women are more sensitive to a small increase in peripheral DA concentration. An abnormal permeability of the blood-brain barrier in IDDM patients could explain a greater exposure of the hypothalamic structures, regulating the pituitary gonadotropin hormone secretion.

Adult↗
PubMed1995

Diet and vitamin D status among pregnant Pakistani women in Oslo.

OBJECTIVES: In the present study the diet and the nutritional status of pregnant Pakistani immigrant women have been compared with a group of Norwegian women. DESIGN: A cross-sectional survey of women in the 18th week of pregnancy. SETTING: Women referred to routine ultrasound examination at Aker and Ullevål Hospitals in Norway. SUBJECTS: All (58) healthy women of Pakistani origin referred from October of 1991 to January of 1992 were included, of whom 38 (66%) participated. Forty-five Norwegian women were randomly included in the same period and 38 (84%) of these women participated. RESULTS: The serum levels of 25-hydroxyvitamin D3 were significantly lower in the Pakistanis compared with the Norwegians (median 19 nmol/l vs 55 nmol/l, P < 0.001) and 83% of the Pakistani women had 25-hydroxyvitamin D3 levels below the reference value (< 30 nmol/l). The Pakistanis had higher levels of serum parathyroid hormone (median 2.6 vs 1.6 pmol/l, P < 0.001). The Pakistanis also had a lower dietary intake of vitamin D than that of the Norwegians (median 2.2 vs 3.3 micrograms/day, P < 0.05), and a lower total intake, including supplements (median 2.9 vs 7.0 micrograms/day, P < 0.001). Among the Pakistanis a correlation was found between the dietary intake of margarine, the main source of vitamin D in the diet, and the concentration of 25-hydroxyvitamin D3 in serum, r = 0.48 (P = 0.01). In general, the Pakistanis avoided any direct sunshine exposure, and no relation between outdoor activity and serum level of 25-hydroxyvitamin D3 was found. The Pakistani women had a lower intake of calcium than the Norwegians (median 793 vs 1134 mg/day, P < 0.001). CONCLUSION: This study has shown that Pakistani women living in Oslo are at great risk of developing vitamin D deficiency during pregnancy. The main reasons for this are avoidance of sun exposure, a low dietary intake of vitamin D, and no or little use of supplementation.

Adult↗
PubMed1994

1,25-dihydroxyvitamin D3 alters the effect of cAMP in thyroid cells by increasing the regulatory subunit type II beta of the cAMP-dependent protein kinase.

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) attenuates the stimulatory effects of cAMP on proliferation and iodide uptake in rat thyroid FRTL-5 cells. This study examines the effects of 1,25-(OH)2D3 on the cAMP-dependent protein kinase (PKA). Cytosol proteins separated by anion exchange chromatography showed increased [3H]cAMP binding activity as well as increased kinase activity in the fractions containing PKA type II in 1,25-(OH)2D3 (10 nM)-treated cells compared to the control cells. Western blot analysis of 1,25-(OH)2D3-treated cells revealed a 4-fold increase in the cytosolic amount of the PKA regulatory subunit RII beta, whereas no changes were detected in the regulatory subunits RI alpha and RII alpha or the catalytic (C) subunit. Northern blot analyses showed a similar increase in RII beta mRNA in cells treated for 12 h with 1,25-(OH)2D3 (10 nM), and RII beta mRNA increased further to 10-fold above control cell level after 96 h of incubation. Iodide uptake was synergistically stimulated with both PKAI- and PKAII-directed pairs of cAMP analogs. The PKAI synergism was, however, inhibited by 1,25-(OH)2D3 treatment of the cells, whereas the PKAII synergism was unaffected. In conclusion, 1,25-(OH)2D3 attenuates both PKAI formation and PKAI-stimulated iodide uptake in rat thyroid FRTL-5 cells by increasing the level of RII beta without altering the other PKA subunit levels.

Animals↗
PubMed1994

[Pituitary apoplexy after injection of pituitary-hormone releasing hormones].

Pituitary apoplexy often occurs spontaneously in adenomas. A few cases have been reported after testing anterior pituitary function by means of intravenous injections of a mixture of gonadotropin-releasing hormone and thyrotropin-releasing hormone, or gonadotropin-releasing hormone alone. In these cases the development of visual field defects has necessitated surgical intervention, which confirmed pituitary apoplexy. We describe a patient with a pituitary macroadenoma. He developed symptoms and signs of pituitary apoplexy immediately after intravenous injection of a mixture of hypothalamic releasing hormones. His visual fields remained normal, and he recovered spontaneously.

Aged↗
PubMed1994

[Determination of estrogen receptors in aspirates from needle biopsies of breast carcinomas. Correlation to a biochemical method].

Several methods exist for determining oestrogen receptor status in breast carcinomas. Biochemical methods have been widely used for many years, but recently immunocytochemical methods have become available. We have compared the outcome of the biochemical and immunocytological analysis in 274 breast cancer patients. Fine needle aspirates from all the patients were investigated immunocytologically and 214 tumours were positive (78%) and 60 negative (22%). Biochemical data were available in 155 patients, and the concordance between the two methods was 88%. Most of the 119 carcinomas (43%) that were only investigated cytologically were too small to allow both histological and biochemical analysis. A minority of patients were not operated on because of high age, and/or impaired health, or because the tumour was inoperable. In our opinion, biochemical and immunocytological methods are equally sensitive and specific in detecting oestrogen receptor in breast tumour tissue. In fine needle aspirates there is the additional advantage of morphological assessment of malignant nuclei and the possibility of obtaining material from small lesions.

Biopsy, Needle↗
PubMed1994

Calcitriol attenuates the basal and vasoactive intestinal peptide-stimulated cAMP production in prolactin-secreting rat pituitary (GH4C1) cells.

A clonal strain of prolactin-producing rat pituitary tumour cells (GH4C1 cells) was used to study the effect of calcitriol on cyclic adenosine monophosphate (cAMP) production. Calcitriol (10 nM) attenuated both the basal and vasoactive intestinal peptide (VIP)-stimulated cAMP production after 2 days' pretreatment of the cells. The effect was detectable at 1 nM and maximal at about 10 nM. Calcitriol was at least 100 times more potent than calcidiol and 24-hydroxycalcidiol. Calcitriol (10 nM, 4 days) did not affect the specific binding of 125I-VIP, but attenuated the guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS)-stimulated (100 microM) adenylyl cyclase activity by 25%. Calcitriol (10 nM, 4 days) also attenuated both the Mn2+ (1 mM) and the forskolin-stimulated (10 microM) adenylyl cyclase activity by 43 and 41%, respectively. In conclusion, these data suggest that calcitriol attenuates the basal and VIP-stimulated cAMP production by inhibiting the catalytic subunit of the adenylyl cyclase as well as the amount of the G protein Gs alpha.

Animals↗
PubMed1994

Vitamin D receptor binding and biological effects of cholecalciferol analogues in rat thyroid cells.

The cholecalciferol analogues 1(S),3(R)-dihydroxy-20(R)-[3'(S)-cyclopropyl-3'-hydroxyprop-1'(E)- enyl]-9,10-secopregna-5(Z),7(E),10(19)-triene (calcipotriol, MC 903), 1(S),3(R)-dihydroxy-20(R)-[3'-ethyl-3'-hydroxy- pentoxy]-9,10-secopregna-5(Z),7(E),10(19)-triene (KH 1060) and 1(S),3(R)-dihydroxy-20(R)-[5'-ethyl-5'-hydroxy-hepta- 1',3'(E)-diene-1'-yl]-9,10-secopregna-5(Z),7(E),10(19)-triene (EB 1089) have been modified in the side chain to increase their effects on cell differentiation and proliferation and to reduce the risk of inducing hypercalcemia. The effects of these analogues were tested on FRTL-5 cells, a strain of continuously growing and well-differentiated rat thyroid cells. FRTL-5 cells express a normal vitamin D receptor (VDR), and 1,25-(OH)2D3 potently attenuates the thyrotropin (TSH) stimulated production of the intracellular signalling molecule 3',5'-cyclic adenosine monophosphate (cAMP), iodide uptake and cell growth of these cells. These effects were also induced by the cholecalciferol analogues after 4 days of incubation. KH 1060 was the biologically most potent of the analogues and, compared to KH 1060, the IC50 values were 1.2-, 2.7- and 14-fold higher when 1,25-(OH)2D3, EB 1089 and MC 903, respectively, were used for the displacement of receptor bound [3H]1,25-(OH)2D3. As indicated by their VDR binding, 1,25-(OH)2D3 and EB 1089 were equipotent inhibitors of the TSH stimulated adenylyl cyclase activity, iodide uptake and FRTL-5 cell growth. The analogue MC 903 was the second most potent inhibitor of cell growth in spite of expressing the lowest affinity for the VDR and the weakest inhibition of TSH-stimulated adenylyl cyclase activity and iodide uptake. In conclusion, the biological effects of these cholecalciferol analogues in rat thyroid FRTL-5 cells seem to be mainly determined by their binding affinity for the VDR, although non-genomic effects can not be excluded.

Adenylyl Cyclases↗
PubMed1994

Somatostatin in human follicular fluid.

To demonstrate the presence of somatostatin in human pre-ovulatory follicular fluid, and to assess the role of this peptide in follicular maturation, a total of 66 follicular fluid samples were obtained from 26 patients at the time of oocyte recovery for in-vitro fertilization. Follicular fluid concentrations of somatostatin, oestradiol, progesterone and androstenedione were measured by immunoassay. Somatostatin concentrations in concomitantly obtained plasma samples were also analysed. Follicular fluid somatostatin concentrations ranged from undetectable (< 1.5 pmol/l) to 109.4 pmol/l. The mean +/- SE somatostatin concentrations in follicular fluid (12.8 +/- 1.8 pmol/l) were significantly (P < 0.0001) increased compared to corresponding plasma concentrations of somatostatin (6.5 +/- 0.2 pmol/l). A significant and positive correlation existed between follicular fluid and plasma somatostatin concentrations (r = 0.27; P < 0.03). No differences in either follicular fluid or plasma somatostatin concentrations were found between different stimulation protocols or diagnostic groups. Neither did follicular fluid somatostatin concentration vary with follicular size. Similarly, no differences in somatostatin concentrations were found between follicular fluids associated with fertilized (13.2 +/- 2.1 pmol/l) or non-fertilized oocytes (10.5 +/- 1.6 pmol/l). Follicular fluid concentrations of somatostatin correlated positively with those of progesterone (r = 0.30; P = < 0.04), but not with those of oestradiol or androstenedione or with the androstenedione/oestradiol ratio. The relationship between follicular fluid somatostatin and progesterone concentrations suggests that follicular fluid somatostatin may have a physiological role in follicular maturation and the luteinization process.

Adult↗
PubMed1994

Carbohydrate-deficient transferrin and other markers of high alcohol consumption: a study of 502 patients admitted consecutively to a medical department.

An isoform of transferrin, carbohydrate-deficient transferrin (CDT) is increased in a high percentage of abusing alcoholics and has been found superior in its specificity compared with other biological markers. We used serum CDT as a screening parameter in 502 patients consecutively admitted to our medical department during a 4-week period. The intake of ethanol during the last 4 weeks was registrated by personal interviews and the mean daily consumption calculated. Serum CDT was measured at admission (CDTect) and compared with gamma-glutamyltranspeptidase (GGT), AST, ALT, and mean corpuscular volume (MCV). Serum CDT detected 18 of 26 (69%) patients who consumed > 50 g ethanol daily. The clinical sensitivity of CDT of detection ethanol consumption > 50 g daily was 69%, compared with 73%, 50%, 35%, and 52% for increased values of GGT, AST, ALT, and MCV, respectively. Altogether, 38 of 476 patients (8%) with a daily ethanol consumption < 50 g also had increased serum CDT levels. The specificity of CDT was 92%, compared with 75%, 82%, 86%, and 85% for GGT, AST, ALT, and MCV, respectively. In the 60 patients who consumed > 10 g ethanol daily, we found a significantly positive correlation between CDT and ethanol consumption (r = 0.52, p < 0.001). A positive correlation was also found between serum transferrin and CDT (r = 0.51, p < 0.001). In conclusion, the specificity of CDT is much higher compared with GGT in detecting alcohol abuse. Some acute and chronic illnesses may increase the serum level of CDT. False-positive CDT levels may be caused by changes in serum transferrin concentration.

Adult↗
PubMed1994

1,25-Dihydroxyvitamin D3 attenuates adenylyl cyclase activity in rat thyroid cells: reduction of thyrotropin receptor number and increase in guanine nucleotide-binding protein Gi-2 alpha.

1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] is the most potent of the naturally occurring vitamin D metabolites. In rat thyroid FRTL-5 cells, 1,25-(OH)2D3 attenuated the increase in TSH-stimulated adenylyl cyclase activity obtained by removing TSH from the culture medium. When cells were incubated with 1,25-(OH)2D3 (10 nmol/liter; 4 days), the binding capacity for specific [125I]TSH binding decreased from 20.1 +/- 1.8 to 8.8 +/- 1.6 fmol/10(6) cells (mean +/- SEM; n = 4; P < 0.01) compared to that in control cells. The Kd did not change (mean +/- SEM, 0.46 +/- 0.09 vs. 0.25 +/- 0.07 nmol/liter; n = 4; P = NS). Western blotting revealed no change in the membrane content of the adenylyl cyclase (AC) stimulatory guanine nucleotide-binding protein (G-protein) alpha-subunit (Gs alpha) during 1,25-(OH)2D3 treatment. Similarly, levels of the AC inhibitory G-protein Gi-3 alpha- and G-protein beta-subunits were not altered by 1,25-(OH)2D3. However, Western blotting with antibodies recognizing both Gi-1 alpha and Gi-2 alpha was augmented 4-fold, presumably representing an increase in Gi-2 alpha only, as Gi-1 alpha messenger RNA (mRNA) was not detected in FRTL-5 cells. 1,25-(OH)2D3 (10 nmol/liter; 4 days) reduced cholera toxin (10 nmol/liter)-stimulated AC activity to 85% of the control value (P < 0.05), whereas forskolin (100 mumol/liter)-stimulated direct activation of AC was inhibited by 39%. The TSH receptor mRNA level correlated to the beta-actin mRNA was 2-fold higher in control cells compared to that in 1,25-(OH)2D3-treated cells 12 h after TSH removal. Only minor alterations in the Gs alpha mRNA/beta-actin mRNA and Gi-3 alpha mRNA/beta-actin mRNA ratios were observed during 1,25-(OH)2D3 treatment, whereas Gi-2 alpha mRNA increased 3-fold compared to that in control cells. No change in the resting intracellular Ca2+ concentration could be detected after 4 days of 1,25-(OH)2D3 treatment. Our studies show that 1,25-(OH)2D3 attenuates AC activity by reducing the TSH receptor number and increasing the level of the AC inhibitory G-protein Gi-2 alpha in FRTL-5 cells.

Actins↗