K Kanda

Nagoya Women's University, Nagoya, Aichi, Japan

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Publications (22)17.09 Total impact

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    ABSTRACT: Our previous studies demonstrated that estrogen (E2) prevents the development of disuse atrophy of the femur in tail-suspended rats. To elucidate the mechanisms of this E2 action, we investigated the effects of E2 on the expression of alkaline phosphatase (ALP, a marker for bone formation) and tartrate-resistant acid phosphatase (TRAP, a marker for bone resorption) in the femur of ovariectomized and tail-suspended rats. One group of ovariectomized rats received estradiol dipropionate (OVX-E2), and the other the vehicle alone (OVX). Each group was subjected to tail-suspension. After 1, 3, 5 or 7 days of suspension, ALP and TRAP mRNA levels were determined by Northern blot analysis. The ALP mRNA level was not altered by suspension in the OVX group, but it gradually increased in the OVX-E2 group, the highest level being observed at day 5 of suspension. In contrast, TRAP mRNA significantly increased at days 5 and 7 in the OVX group, while it is decreased significantly from day 3 to 7 in the OVX-E2 group. These results indicate that E2 prevents disuse atrophy of the femur in an ovariectomized and tail-suspended rat model by stimulating bone formation and by inhibiting bone resorption.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 01/2002; 45(2):55-7.
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    ABSTRACT: It is known that estrogen deficiency results in osteoporosis in human and experimental animals. However, how this deficiency affects the development of disuse bone atrophy is not well understood. Recently, it has been reported that estrogen affects the production of cytokines such as interleukin 6 (IL-6) which acts as local bone-resorbing factor. We thus studied how estrogen deficiency caused by ovariectomy and estrogen supplements affects the expression of IL-6 mRNA in the femur of tail-suspended rats. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received an intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received the vehicle alone (OVX group). After the third injection, the rats were subjected to tail suspension in metabolic cages for 1, 3, 5 and 7 days. The wet weight of femurs significantly decreased after day 3 of tail-suspension in the OVX group. However, no significant decrease was observed in the OVX-E2 group. The expression of IL-6 mRNA estimated by RT-PCR (reverse transcription coupled polymerase chain reaction) in the femur significantly increased on day 5 after tail suspension in the OVX group. In the OVX-E2 group, that level significantly decreased on day 1 after the commencement of tail suspension. During suspension the level tended to be lower than that in the OVX group, a significant difference being observed on days 5 and 7 of suspension. The present results suggest that estrogen administration to OVX rats prevents both IL-6 production in the femur and the development of disuse bone atrophy induced by tail suspension.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 01/2002; 45(1):12-4.
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    ABSTRACT: It is well known that estrogen deficiency results in osteoporosis in human and experimental animals. However, how its deficiency affects the development of disuse atrophy is not well understood. We thus investigated how estrogen deficiency caused by ovariectomy and estrogen supplements affect serum levels of calcium, parathyroid hormone (PTH), and 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) in tail-suspended rats. Five-week-old female Wistar rats were ovariectomized and divided into two groups. One group received an intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received the vehicle alone (OVX group). After the third injection, the rats were subjected to tail-suspension in metabolic cages for 1, 3, 5 or 7 days. In the OVX group, urinary excretion of deoxypyridinoline (D-Pyr) tended to increase on day 1 after tail-suspension. In the OVX-E2 group, basal excretion was lower than that in the OVX group, and no increase was observed after the suspension. Serum concentrations of ionized calcium significantly increased on day 1 after the suspension in both groups. However, in the OVX-E2 group, the level tended to be higher than those in the OVX group from day 0 to day 3. Serum PTH tended to decrease on day 1 after suspension in the OVX group. In the OVX-E2 group, it did not change during the suspension, but the levels were higher than those in the OVX group during the experiment. Serum 1,25(OH)2D3 transiently and significantly increased on day 1 after suspension in both groups. However, in the OVX group, the level was significantly higher than that in the OVX-E2 group. These data indicate that estrogen treatment of ovariectomized rats modifies the changes in calcium metabolism induced by tail-suspension.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 01/2001; 44(2):75-8.
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    ABSTRACT: We investigated the effect of estrogen (E2) and tail-suspension on expression of osteocalcin (OC) mRNA in the femur of ovariectomized rats. Five-week-old female Wistar rats were ovariectomized and divided into two groups: one group received estradiol dipropionate (OVX-E2), and the other received the vehicle (OVX). Each group was further divided into two subgroups, tail-suspended (S) and non-suspended (N), giving a total of four groups: OVX-E2-S, OVX-E2-N, OVX-S and OVX-N. After a 7-day suspension, femurs were excised, and OC mRNA levels were determined by Northern blot analysis. A significant decrease of OC mRNA in OVX-E2-N was observed when compared with that of OVX-N, indicating that E2 decreases the OC expression. Interestingly, tail-suspension further decreased the mRNA levels in both OVX-S and OVX-E2-S when compared with the levels of OVX-N and OVX-E2-N, respectively. Since glucocorticoids have been shown to decrease OC expression, we also measured the urinary excretion of corticosterone during the suspension period that reflects the serum levels of corticosterone, and found that it was increased by E2 and further increased by tail-suspension. These results indicate that estrogen and glucocorticoids exert additive effects in inhibiting OC expression in the rat femur.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 01/2001; 44(2):82-4.
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    ABSTRACT: Urinary excretion of deoxypyridinoline (D-Pyr) has been shown to be a useful marker for bone resorption. In this study, we investigated whether D-Pyr could be used to monitor the changes in bone resorption of the hind limb induced by tail-suspension. Male Wistar rats 5-weeks old were tail-suspended in a metabolic cage to unload the hind limbs. The control rats were not suspended. YH529 (YH), an inhibitor of bone resorption, or a vehicle (phosphate buffered saline=PBS) was administered daily starting 3 days before the commencement of tail-suspension. In the non-suspended rats receiving PBS, urinary excretion of D-Pyr did not show any significant change during the one-week experimental period. In the non-suspended rats receiving YH, D-Pyr excretion significantly decreased on day 5 and 7 when compared with that observed on day 0, in accordance with the systemic inhibition of bone resorption by YH. In the tail-suspended rats receiving PBS, D-Pyr excretion showed a tendency to increase on day 1, which is in agreement with our previous report that tail-suspension causes an early (on day 1 of suspension) and transient increase in bone-resorption of the hind limbs. In the tail-suspended rats treated with YH, the increase in D-Pyr excretion on day 1 was not observed, and a significantly lower excretion was noted from day 3 to 7 during the tail-suspension. It was suggested that D-Pyr excretion might reflect the transient increase in hind limb bone resorption induced by tail-suspension. As observed in-YH treated rats, D-Pyr excretion could serve as a good marker for the inhibition of systemic bone resorption.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1998; 42(1):11-3.
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    ABSTRACT: Rat tail-suspension induces disuse atrophy of muscles and bones in hindlimbs. In the present investigation we studied how ovariectomy and estrogen substitution affect the development of the disuse atrophy induced by suspension. Five-week old female Wistar rats were ovariectomized and divided into two groups. One group received intramuscular injection of estradiol dipropionate once a week (OVX-E2 group), and the other received a vehicle injection (OVX group). After the third injection, each group was further divided into two groups, tail-suspended and non-suspended. After 7 days of tail-suspension, a significant decrease in the wet weight of femurs and their Ca and Pi content was observed in the OVX group. However, no significant change in those parameters was observed in the E2 group. In both E2 and OVX groups, a significant decrease in the wet weight of soleus and gastrocnemius muscles was demonstrated after the suspension. This demonstrated that estrogen administration to ovariectomized rats prevents the development of disuse bone atrophy but not that of muscle atrophy, suggesting that estrogen plays important roles in bone remodeling.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 01/1998; 41(2):89-92.
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    ABSTRACT: We demonstrated that administration of a bisphosphonate, YH529, prevents the development of disuse atrophy of the hind limbs induced by tail-suspension in rats. Since tail suspension is accompanied by an increase in the secretion of stress hormones, we studied whether administration of bisphosphonate affects the secretion of stress hormones during that procedure. Tail suspension was carried out in a metabolic cage by connecting a wire inserted through tail bone to the ceiling of the cage. The control rat received the same treatment but was not suspended. YH529 or a vehicle (PBS=phosphate buffered saline) was administered daily starting 3 days before the commencement of tail suspension. Urine samples were collected before the wire was inserted (day 0), on the day of insertion (day 1) and 3, 5 and 7 days after. In the control rats receiving PBS, urinary excretion of corticosterone and epinephrine did not change throughout the 7-day experimental period. In the control rats receiving YH529, urinary excretion of corticosterone increased significantly on the day of tail-piercing and wiring but then returned to the prior level. This increase was not observed in the control group receiving PBS. In the tail suspended rats, excretion of corticosterone and epinephrine increased significantly in both PBS and YH529 groups, the highest level being observed on the first day of tail suspension. Although statistically not significant, corticosterone excretion on day 1 of tail suspension was higher in the YH529 groups than that in the PBS group. It is thus suggested that administration of YH529 causes an augmented response to stress load.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1997; 41(1):9-12.
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    ABSTRACT: We recently demonstrated that osteopenia induced by rat tail-suspension was associated with an initial increase in bone resorption. To study the significance of the increase in early bone resorption for osteopenia, we investigated whether administration of YH529, a third-generation bisphosphonate, prevents the development of osteopenia as evidenced by increased wet weight of the femur, together with its calcium and phosphorus contents, when compared with those of tail-suspended rats treated with the vehicle alone. These results suggested that the initial increase in bone resorption plays an important role in the development of osteopenia induced by tail suspension.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1997; 41(1):16-7.
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    ABSTRACT: Our previous studies demonstrated that tail suspension causes early, transient increases in osteoclastic activity, followed by a decrease in osteoblastic activity in the hind limbs of rats. To assess whether this early increase in bone resorption is important in the development of disuse atrophy, the effect of YH529, a third generation bisphosphonate, was studied on hind limb atrophy in rats subjected to tail suspension. YH529 (YH group) or PBS (control group) were administered subcutaneously in 5-week-old male Wistar rats suspended for 7 days. In the control group, wet weight, calcium and phosphorus contents decreased significantly in the femur but they did not change in the humerus. In the YH group, however, these parameters did not change significantly in the femur, but both calcium and phosphorus increased significantly in the humerus. These results indicate that the inhibition of bone resorption by YH529 prevents the development of disuse atrophy induced by tail suspension. It is thus suggested that early increases in bone resorption are important for the development of disuse bone atrophy.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1996; 40(1):39-42.
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    ABSTRACT: To study the effects of mechanical unloading on systemic calcium homeostasis, we determined the changes in serum concentration of calcium, 1,25-dihydroxyvitamin D3 and parathyroid hormone (PTH) during tail-suspension experiments in rats. The serum concentration of ionized calcium significantly increased during the 14 days of the suspension, reflecting increased bone resorption in the hind limbs. This hypercalcemic condition should cause suppression in PTH secretion. Indeed, serum PTH levels decreased on Day 3 of the suspension. This decrease was associated with lower serum levels of 1,25-dihydroxyvitamin [correction of dihyroxyvitamin] D3 probably due to a decrease in the activity of 1 alpha-hydroxylase in the kidneys resulting from a decrease in PTH secretion. Since it is known that 1,25-dihydroxyvitamin D3 stimulates osteoblastic function, it is suggested that endocrine responses evoked by tail suspension aggravate disuse atrophy of the hind limbs.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1996; 40(1):43-6.
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    ABSTRACT: The catecholamine response to acute stress has been shown to change with age. However, alterations under chronic stress conditions have not been established. This study attempted to determine whether aging modifies the catecholamine response to chronic stress load in rats subjected to tail suspension. Urinary excretions of epinephrine (E) and norepinephrine (NE) were monitored before and during the tail suspension experiments in rats at two different ages: 5 weeks old (young) and 18 months old (aged). Basal excretions of E and NE before the suspension were higher in the aged rats, indicating that sympathetic-adrenal medullary activities increase with age under resting conditions. The chronic stress load elicited E responses in the aged rats similar to those in the young rats. The NE responses, however, were completely different in that tail suspension caused a greater increase in NE excretion in the young rats than in the aged rats. This finding suggests that the sympathetic response to chronic stress load changes with age.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1995; 39(2):107-11.
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    ABSTRACT: Voltage-dependent K+ channels contribute to the repolarization phase of the cardiac action potential. An increase in Kv1.5 K+ channel gene expression by a pharmacological dose of glucocorticoid was reported recently in the heart of an adrenalectomized rat. In this study, we examined whether physiological elevations of glucocorticoid induced by tail suspension affects the K+ channel gene expression. Five-week-old male Wistar rats were subjected to tail suspension for three days. Total RNA was extracted from the ventricle, and the level of Kv1.5 mRNA was determined by Northern blot analysis. On the first day, the Kv1.5 mRNA had increased over the non-suspended rat. By the third day, mRNA had increased significantly by more than 3-fold. knowing that urinary excretions of glucocorticoid increase in tail-suspended rats, these findings suggest that physiologically elevated glucocorticoid may upregulate Kv1.5 K+ gene expression.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 11/1995; 39(2):141-4.
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    ABSTRACT: To elucidate the mechanism in disuse bone atrophy induced by skeletal unloading, we studied the indices of bone resorption and bone formation in the femur of tail-suspended rats. The duration of the suspension ranged from 1 to 14 days. Tartrate-resistant acid phosphatase mRNA, an index used to evaluate bone resorption, increased significantly more than the controls for the first 3 days of the tail-suspension experiments, compared those in controls. Osteocalcin and alkaline phosphatase, two common markers for bone formation, were also monitored. Osteocalcin mRNA started to decrease after 3 days of suspension. Five days later, alkaline phosphatase mRNA showed a decrease. Levels of both of these mRNAs remained low for the remaining suspension period. Sequential changes in the markers for bone metabolism indicate that the transient increase in bone resorption preceded the decrease in bone formation in the development of disuse bone atrophy induced by skeletal unloading.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 09/1995; 39(1):21-4.
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    ABSTRACT: Adrenal insufficiency in human and rat is associated with an impairment of the diuretic response to water load, and only glucorticoids (GCs) restore this deficit. Our observation that GCs potentiate atrial natriuretic polypeptide (ANP)-stimulated cGMP production in cultured renal cells prompted us to examine the possibility that GCs may restore the diuretic response through the potentiation of ANP action. Initially, changes in urine volume and ANP levels were studied in adrenalectomized (Adx) and sham-operated intact rats after an oral water load of 5 ml/100 g BW. Urine volume after water load was 4.5 +/- 0.5 ml/30 min in the intact rats, whereas it was 0.8 +/- 0.2 ml/30 min in the Adx rats. In the intact rats, a significant increase in plasma ANP level was observed 30 min after the water load, whereas no increase was observed in Adx rats. This defective ANP response may be involved in the impairment of the diuretic response in Adx rats. Indeed, pretreatment of Adx rats with dexamethasone (Dex, 20 micrograms/100 g BW) increased plasma ANP levels even before water load and improved diuretic response. Subsequently, effect of iv administration of human or rat ANP at a pharmacological dose (2.5 micrograms/100 g BW) on urine volume, osmolarity, and urinary excretion of cGMP, and sodium was studied in Adx rats that received an oral water load 30 min before ANP. Dex treatment was achieved by per os administration 3 h before the ANP injection. In Adx rats, the urine volume after ANP administration was 1.2 +/- 0.1 ml/30 min, and pretreatment with Dex markedly increased the urine volume to 6.3 +/- 0.4 ml/30 min. Dex also increased ANP-induced osmolar and sodium excretion by 2.6- and 2.9-fold, respectively. Although urinary excretion of cGMP was increased in Adx rats by ANP administration, a further significant increase was observed by the pretreatment with Dex. Injection of (Bu)2cGMP to Adx rats pretreated with Dex resulted in a significant increase in urine volume and osmolar and sodium excretion. However, no significant increase in urine volume was observed in Adx rats not pretreated with Dex. The present study suggests that GCs restore the diuretic response to acute water load not only by increasing the secretion of ANP but also by potentiating ANP-stimulated cGMP production. Furthermore, GCs may augment ANP action at one or more steps other than cGMP formation because administration of (Bu)2cGMP to Adx rats did not correct the diuretic response to water load.
    Endocrinology 01/1995; 135(6):2459-64. · 4.72 Impact Factor
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    ABSTRACT: We recently showed that increased glucocorticoid secretion aggravates disuse atrophy when induced by skeletal unloading. Disuse atrophy in the elderly is becoming a serious problem in many developed countries. In this study we attempted to examine how aging affects the glucocorticoid response to skeletal unloading. Three groups of rats (aged 5 weeks, 12 months and 18 months) were subjected to 7 days of hind limb unloading by tail-suspension. Urinary excretion of corticosterone over a 24-hr period were monitored every other day. Corticosterone excretion in the control group of 5-week-old rats was initially 87.4 +/- 12.8 ng/day and did not change throughout the experiment. Tail-suspension experiments yielded a significant increase (more than 3 fold) in excretion on days 1 and 3 of the suspension before returning to control levels. In the 12-month-old rats, a marked increase in the basal corticosterone level was observed in the control rats throughout the experiment, while the increase by tail-suspension was attenuated with a transient, significant increase on day 5. In 18-month-old rats, a further increase in the basal level was observed in the control group, although excretions tended to increase steadily from day 1 to day 3 and remained high until day 7. Urinary excretion of corticosterone among the 18-month-old suspension group was similar to those observed in the control group. These results indicate that the younger (5-week-old) rats adapted the stress load caused either by tail-suspension or manipulation alone faster than the older rats did (12 or 18 months old). The observation that basal corticosterone excretion increases with age suggests, alterations in the hypothalamic-pituitary-adrenal axis among the aged rats which might aggravates disuse atrophy induced by skeletal unloading.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 02/1994; 38(1):7-12.
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    ABSTRACT: To elucidate the mechanism involved in the development of disuse atrophy of bone by skeletal unloading, changes in osteocalcin and alkaline phosphatase mRNAs, markers for bone formation, were studied in the hind limb bones of tail-suspended rats. Tail suspension for 8 and 14 days resulted in a significant decrease in osteocalcin mRNA in the femur when compared with age-matched non-suspended controls. Serum 1,25-dihydroxyvitamin D3 decreased to 60% of the control level after 8 days of skeletal unloading but regained almost normal levels over the next 7 days. Since it is known that vitamin D3 up regulates and glucocorticoid down regulates transcription of the osteocalcin gene, the endocrine response evoked by tail suspension may have aggravated the disuse atrophy caused by skeletal unloading in this study.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 02/1994; 38(2):103-6.
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    ABSTRACT: Tail-suspension of rats has been employed for the study of disuse atrophy of hindlimb muscles and bones. From our study, it is suggested that stress exacerbates muscle and bone atrophy; however, the determination of stress hormones has been inappropriately performed. For assessing the effect of tail suspension on stress hormone secretion, suspension was performed for 7 days in a metabolic cage. Urinary excretions of corticosterone, catecholamines and antidiuretic hormone were determined during the 7-day suspension. Urine volume was unchanged during the suspension period, whereas water consumption was decreased during suspension. Urinary excretion of corticosterone and catecholamines increased significantly during the initial 3 days of suspension. The excretion of antidiuretic hormone increased throughout the suspension period. Our results demonstrated that the determination of urinary excretion of these hormones is useful for evaluating the stress reaction.
    Environmental medicine : annual report of the Research Institute of Environmental Medicine, Nagoya University. 02/1993; 37(1):39-41.
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    ABSTRACT: ACTH rapidly and transiently increases c-fos mRNA in the rat adrenals in vivo. The present investigation was undertaken in order to determine what kind(s) of second messenger systems is involved in this increase. Rat adrenal cells were grown in monolayers in Dulbecco's modified Eagle's medium supplemented with 10% fetal bovine serum. After 2 days of culture, cells were treated with ACTH and various agents alone or in combination. The amount of c-fos mRNA was determined by dot blot hybridization and corticosterone levels in the media were measured by RIA. ACTH (300 pg/ml) increased c-fos mRNA transiently with a peak level after 60 min. A similar increase was observed when (Bu)2cAMP (1 mM) was substituted for ACTH. Pretreatment with N-[2-(p-bromocinnamylamino)ethyl]-5-isoquinoline-sulfonamide (H-89), a selective inhibitor of cAMP-dependent protein kinase, suppressed both basal and ACTH-increased c-fos mRNA. H-89 also suppressed corticosterone production. On the other hand, neither 12-O-tetradecanoyl-phorbol-13-acetate (100 ng/ml) nor elevated potassium ion (50 mM) affected the amount of c-fos mRNA and corticosterone production. Furthermore, pretreatment with cycloheximide (5 micrograms/ml) increased both basal and ACTH-increased c-fos mRNA. These results indicate that ACTH increases c-fos mRNA by phosphorylation of preexisting trans-acting factor(s) via cAMP-dependent protein kinase in common with steroidogenesis.
    Endocrinology 07/1992; 130(6):3231-6. · 4.72 Impact Factor
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    ABSTRACT: The present study was undertaken to examine whether sulfonamide-derived diuretics affect [Arg8]vasopressin (AVP)-stimulated or atrial natriuretic peptide (ANP)-stimulated cyclic nucleotide formation in cells cultured from rat or dog kidney. In rat renal cells, all four sulfonamide-derived diuretics examined significantly suppressed 10(-9) M AVP-stimulated cAMP formation at concentrations of 10(-4) and 10(-3) M, while basal cAMP formation was unchanged by the diuretics. When cells were stimulated with 10(-7) M AVP, low ceiling diuretics (indapamide and trichlormethiazide) did not suppress cAMP formation, while high ceiling diuretics (furosemide and azosemide) significantly suppressed cAMP formation at concentrations of 10(-4) and 10(-3) M. The suppressive effect of the diuretics on AVP-stimulated cAMP formation in vitro paralleled the reported diuretic potency of the agents in vivo. In dog renal cells, all four diuretics significantly suppressed 10(-9) M AVP-stimulated cAMP formation at concentrations from 10(-6) to 10(-5) M, while these diuretics did not change basal cAMP levels. High ceiling diuretics suppressed 10(-7) M AVP-stimulated cAMP formation, whereas low ceiling diuretics did not. The difference in effective doses between rats and dogs seems to be consistent with the species difference observed in vivo. None of the diuretics affected basal levels of intracellular cGMP or ANP-stimulated cGMP formation in cultured rat renal cells. In addition to the inhibition of the Na/K/Cl co-transporter, it is suggested that most sulfonamide-derived diuretics act, at least in part, by inhibiting the actions of AVP.
    European Journal of Pharmacology 02/1991; 192(1):153-9. · 2.59 Impact Factor
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    ABSTRACT: 1. The effect of steroid hormones on atrial natriuretic peptide (ANP)-stimulated cyclic guanosine monophosphate (cyclic GMP) formation was studied in cultured rat renal cells. 2. ANP increased cyclic GMP formation in a dose-dependent manner, while cyclic AMP was not changed by ANP. 3. Steroid hormones did not affect basal cyclic GMP levels in cultured rat renal cells. 4. Dexamethasone at 10(-8) M increased ANP (human and rat ANP)-stimulated cyclic GMP dose-dependently in cultured rat renal cells. Cortisol, corticosterone and aldosterone at a concentration of 10(-7) M also potentiated ANP-stimulated cyclic GMP formation, although triiodothyronine, oestradiol and testosterone were ineffective. Potentiation of ANP action by these steroids seems to parallel glucocorticoid activity. 5. Dexamethasone did not affect cyclic GMP formation stimulated by sodium nitroprusside which stimulates soluble guanylate cyclase in the cytosol. Therefore, the potentiating action of dexamethasone may be mediated through the action on particulate guanylate cyclase at the plasma membrane. 6. It is suggested that the diuretic action of glucocorticoids may, at least in part, be mediated through the potentiating effect of glucocorticoids on cyclic GMP response to ANP.
    British Journal of Pharmacology 05/1989; 96(4):795-800. · 5.07 Impact Factor

Publication Stats

69 Citations
17.09 Total Impact Points

Institutions

  • 2002
    • Nagoya Women's University
      Nagoya, Aichi, Japan
  • 1988–2002
    • Nagoya University
      • Research Institute of Environmental Medicine
      Nagoya-shi, Aichi-ken, Japan