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T Sakemi

Publications and source records attributed to T Sakemi.

At least 37 records · Page 2Linked to original sources
PubMed1998

Estrogen replacement therapy with its physiological dose does not eliminate the aggravating effect of ovariectomy on glomerular injury in hypercholesterolemic female Imai rats.

Hypercholesterolemic Imai rats spontaneously develop proteinuria and glomerulosclerosis, especially in males. Estrogen administration attenuated glomerular injury in male Imai rats, and the aggravating effect of ovariectomy in female rats is found. To clarify whether this aggravating effect of ovariectomy is due to a lack of estrogen, we administered estrogen to ovariectomized female Imai rats. At 6 weeks of age, group 1 (control) was sham-operated and group 2 was ovariectomized. Groups 3 and 4 were ovariectomized and received estrogen replacement therapy (0.1 mg in group 3 and 0.2 mg in group 4 once a month subcutaneously). Body weight, urinary protein and serum constituents were investigated every month from 3 to 6 months of age. At 6 months of age, rats were studied morphologically. Estrogen replacement therapy increased serum estrogen to levels close to those of controls when 0.1 mg was used, or higher when 0.2 mg was used. Estrogen replacement therapy with 0.1 mg did not eliminate the aggravating effect of ovariectomy on glomerular injury and rather aggravated it, but conversely therapy with 0.2 mg attenuated glomerular injury and abolished the aggravating effect of ovariectomy. Estrogen replacement therapy markedly elevated serum GH levels dose-dependently. These results suggested that other hormones as well as estrogen may play a protective role of the ovary for the development of glomerular injury, and that estrogen seems to exert a dual effect on glomerular injury.

Animals↗
PubMed1998

Fibrillar crystal structure in essential monoclonal IgM kappa cryoglobulinemia.

In monoclonal IgG cryoglobulinemia, two types of crystallization have been demonstrated with electron microscopy at high magnification. In contrast, little information is available on well-defined crystallization in cases of monoclonal IgM cryoglobulinemia. We present a case of pure monoclonal IgM kappa cryoglobulinemia and rapidly progressive glomerulonephritis occurring in a 75-year-old woman. We detected unequivocal formation of fibrillar crystal structure within intraglomerular macrophages on electron microscopy: the structure accords with that in a case of monoclonal IgG cyroglobulinemia described in the literature.

Aged↗
PubMed1998

Acute renal failure due to hypokalemic rhabdomyolysis in Gitelman's syndrome.

A 46-year-old-male developed acute renal failure (ARF) secondary to hypokalemic rhabdomyolysis. Potassium supplementation restored renal function following improvement of the rhabdomyolysis. After recovery from ARF, further evaluation disclosed he had hypokalemic metabolic alkalosis, normotensive hyperreninemia, hyperaldosteronism, renal hypomagnesemia, hypocalciuria and hyperplasia of the juxtaglomerular apparatus which are a diagnostic set of disorders in Gitelman's syndrome, a variant of Bartter's syndrome. This is the first reported case of ARF due to hypokalemic rhabdomyolysis associated with Gitelman's syndrome.

Acute Kidney Injury↗
PubMed1997

The ovaries attenuate the aggravating effect of testosterone on glomerular injury in Adriamycin-induced nephropathy of female rats.

To clarify whether the ovaries have a potential to attenuate the aggravating effect of testosterone (T) on glomerular injury, we investigated the effect of T in female rats with or without ovaries, using Adriamycin (ADR)-induced nephropathy in female Sprague-Dawley rats. Group 1 consisted of female control rats, group 2 received T, groups 3 and 4 were subjected to ovariectomy (OVX) at 5 weeks of age, and group 4 received further T treatment. Group 5 consisted of male control rats. T was injected subcutaneously every 4 weeks from 5 weeks of age through the end of the experiment. ADR 2 mg/kg was administered intravenously to all rats twice, at 8 weeks of age and 20 days later. Body weight, blood pressure, urinary protein and serum constituents were investigated every 4 weeks from 4 through 24 weeks after the second ADR injection. Each group was studied morphologically 24 weeks after the second ADR injection. Treatment with T or with OVX and T significantly increased the urinary protein excretion. OVX had no significant effect on the urinary protein excretion. Treatment with either T or OVX did not induce any significant effects on the renal function with regard to blood urea nitrogen (BUN), serum creatinine (Cr) and Cr clearance (Ccr) levels, but a combined treatment with OVX and T significantly lowered the serum albumin levels, increased the levels of BUN and Cr and lowered the Ccr values. The glomerulosclerosis index was significantly and markedly higher in control male rats than in control females. Treatment with T resulted in a slight but significant increase in glomerular injury to levels similar to those seen in ovariectomized rats. Combined treatment with OVX and T significantly aggravated glomerular injury in a somewhat accelerated manner, associated with a significant increase in glomerular tuft volume. Our results suggested that the ovaries could not completely suppress glomerular injury worsened by T administered at serum levels similar to those of male rats, but they had a potential to attenuate glomerular injury induced by T, and the protective effect of the ovaries on glomerular injury may be related to their attenuating effect on glomerular growth.

Animals↗
PubMed1997

Testosterone does not eliminate the attenuating effect of estrogen on progressive glomerular injury in estrogen-treated hypercholesterolemic male Imai rats.

Hypercholesterolemic Imai rats spontaneously develop proteinuria and glomerulosclerosis, especially males. Estrogen attenuates the progressive glomerular injury in these male rats. To clarify whether this attenuating effect of estrogen depends on a reduction of testosterone and/or a reduction of the sex-related factors, we investigated whether testosterone administration eliminates the attenuating effect of estrogen on the development of glomerular injury in estrogen-treated male Imai rats. Estrogen significantly reduced sex-related low molecular weight protein excretion to undetectable levels; and treatment with estrogen and testosterone failed to increase these levels. Unexpectedly, treatment with estrogen and testosterone attenuated glomerular injury more than treatment with estrogen only. Estrogen significantly increased both levels of estrogen and growth hormone (GH), whereas it suppressed testosterone levels. Testosterone administration resulted in an increase in serum testosterone levels of about fivefold above the control levels, but reduced the elevated serum GH to the levels of the controls. These results suggest that estrogen appears to play a protective role by itself or in association with sex-related factors, independent of the levels of serum testosterone, and that testosterone does not exert its effect on augmenting glomerular injury and rather may act to attenuate glomerular injury associated with a reduction of GH levels.

Aging↗
PubMed1997

Attenuating effect of castration on glomerular injury is age-dependent in unilaterally nephrectomized male Sprague-Dawley rats.

To clarify a role of sex hormones in greater susceptibility of young rats than adults to the development of focal and segmental glomerulosclerosis (FSGS), we castrated animals at different ages and investigated whether the attenuating effect of castration on FSGS is age-dependent in unilaterally nephrectomized male Sprague-Dawley (SD) rats. At 6 weeks of age, all groups received unilateral right nephrectomy (Nx) and group 2 was simultaneously castrated, while group 1 received a sham operation. Group 3 was castrated at 3 months of age, and group 4 at 6 months of age. Body weight, blood pressure, urinary protein and serum constituents were investigated every 2 months from 4 to 14 months of age. At 6 and 14 months of age, rats were studied morphologically. Castration at 6 weeks of age or at 3 months of age significantly inhibited the compensatory glomerular hypertrophy and hyperfunction with regard to the creatinine clearance as seen in Nx rats at 6 months of age and significantly reduced glomerular injury at the end of the experiment, while castration at 6 months produced neither an inhibitory effect on glomerular hypertrophy nor an attenuating effect on glomerular injury. Serum levels of growth hormone (GH) and somatomedin-C (SmC) were decreased by castration to a greater extent when castrated at younger age. These findings indicated that GH and SmC influenced by male sex hormone seem to play a more important role at younger age than in adults in exerting its effect on glomerular growth, leading somehow to glomerular injury in aging, unilaterally nephrectomized male SD rats.

Aging↗
PubMed1997

Different effect of estrogen administration from castration on glomerular injury in unilaterally nephrectomized male Sprague-Dawley rats.

We have already reported an equally attenuating effect of castration or estrogen administration on the development of focal segmental glomerulosclerosis (FSGS) in the animal models of a short-term experimental period ended at 24 weeks. In the present study, to clarify the importance of the experimental period in studying the pathogenesis of the development of FSGS, we investigated a long-term effect of castration or estrogen administration on FSGS using an experimental model of uninephrectomized Sprague-Dawley (SD) rats ended at 54 weeks. Thirty male SD rats received unilaterally right nephrectomy at 6 weeks of age. They were divided into three groups: group 1 was control; group 2 was castrated at 6 weeks, and group 3 was administered 0.2 mg estrogen subcutaneously once a month from 6 weeks of age. Body weight, urinary protein, serum albumin and other serum constituents were investigated every 12 weeks from 18 to 54 weeks of age. Each group was studied morphologically at the end of the experiment. Castration attenuated glomerular injury to the same extent as seen in the study of a short-term experimental period, while estrogen administration failed to attenuate glomerular injury, although each treatment equally suppressed an urinary excretion of a sex-related low-molecular-weight (LMW) protein. Castration reduced significantly kidney weight (KW), glomerular volume (GV) and serum growth hormone (GH) levels, but estrogen treatment failed to reduce KW and GV, and conversely elevated GH levels. These results suggest that a sex-related LMW protein influenced by castration or estrogen treatment may not play an important role in the development of FSGS and that an increase in plasma GH levels may contribute to the failure of an attenuating effect of estrogen on glomerular injury.

Animals↗
PubMed1997

Systemic lupus erythematosus in a patient with remitting minimal change nephrotic syndrome.

Minimal change nephrotic syndrome (MCNS) developed in a 17-year-old female and spontaneously remitted. One month later the nephrotic syndrome relapsed. Prednisolone therapy, 60 mg/day, was started and resulted in a full remission within a week and the prednisolone dose was subsequently tapered. Seven months later, when 10 mg/day of prednisolone was being administered, she developed erythematous rash with photosensitivity and polyarthralgia without exacerbation of the nephrotic syndrome, and fulfilled four of the American College of Rheumatology criteria for classification of systemic lupus erythematosus (SLE). Avoidance of direct sunlight ameliorated the erythematous rash and the polyarthralgia disappeared even though the prednisolone dose was decreased further. This is the first reported case of SLE developed in a patient with remitting MCNS.

Adolescent↗
PubMed1996

Sex difference in progression of adriamycin-induced nephropathy in rats.

To clarify the pathogenesis of focal-segmental glomerulosclerosis, we investigated the sex-related difference and the effect of castration in Adriamycin (ADR) induced nephropathy of Sprague-Dawley rats. At 5 weeks of age, group 1 female and group 2 male rats were sham operated, and group 3 male rats were castrated. ADR 2 mg/kg was intravenously administered to all rats at 8 weeks of age twice at a 20-day interval. Body weight, blood pressure, urinary protein, and serum constituents were investigated every 4 weeks, 4-20 weeks after the second ADR injection. Each group was studied morphologically 12 and 20 weeks after the second ADR injection. ADR induced massive proteinuria in male rats, whereas it induced significantly lower proteinuria in female rats, and castration significantly reduced proteinuria of male rats to an extent equal to the levels seen in female rats. Control male rats had significantly lower serum albumin levels and a significantly greater impairment of renal function (blood urea nitrogen and creatinine levels) than the female rats or the castrated male rats at 20 weeks. The glomerulosclerosis index was significantly higher in control male rats than in female rats, and castration attenuated glomerular injury of male rats to an extent close to the levels seen in female rats, though there was a significant difference in the glomerulosclerosis index between female rats and castrated male rats. The three groups did not differ in blood pressure and plasma somatomedin C and serum growth hormone levels, whereas the plasma testosterone levels were decreased to undetectable in female and castrated male rats, resulting in a reduction of sex-related low molecular weight protein in urine. These observations suggest that sex hormones such as testosterone and estrogen and/or sex-related low molecular weight protein regulated by testosterone and estrogen may play a contributory role in sex differences in the progression of glomerulosclerosis in ADR-treated rats.

Animals↗
PubMed1996

Effect of ovariectomy on glomerular injury in hypercholesterolemic female Imai rats.

To clarify the pathogenesis of focal and segmental glomerulosclerosis, we investigated the effect of ovariectomy in hypercholesterolemic female Imai rats. At 5 weeks of age, control female (group 1) and control male rats (group 3) were sham-operated, female rats (group 2) were ovariectomized and male rats (group 4) were castrated. Body weight, blood pressure, urinary protein and serum constituents were checked every 2 months from 2 through 12 months of age. All groups were studied morphologically at 6 months of age and further female groups (1 and 2) studied at 12 months. Both control female and control male rats developed marked proteinuria, to a significantly greater extent in the male rats. Castration reduced proteinuria, while ovariectomy did not influence it and there were no significant differences in proteinuria among the control females, the ovariectomized females and the castrated males. Control male rats had significantly lower serum albumin levels, higher cholesterol levels and a significantly greater impairment of renal function in blood urea nitrogen (BUN) levels than did the control female rats at 6 months. Castration significantly increased serum albumin levels and lowered BUN levels, while ovariectomy did not basically influence these values in the female rats. The glomerulosclerosis index at 6 months of age was significantly higher in the control males than in the control females. Castration attenuated glomerular injury, while ovariectomy aggravated glomerular injury to the same levels as found in the castrated males. This aggravating effect of ovariectomy observed at 6 months, however, disappeared at 12 months. These results suggested that sex-related factors regulated by the ovaries may play an inhibitory role in the development of glomerulosclerosis before 6 months of age, but not thereafter, in hypercholesterolemic female Imai rats.

Animals↗