- Email: [email protected]
Effect of aging on urinary excretion of 18-hydroxycortisol
ft. Steroid Biochem. Molec. Biol. Vol. 50, No. 3/4, pp. 167-168, 1994 Copyright © 1994 Elsevier Science Ltd 0960-0760(94)E0083-W Printed in Great Britain. All rights reserved 0960-0760/94 $7.00 + 0.00
Pergamon
Effect of A g i n g on U r i n a r y E x c r e t i o n of 18-Hydroxycortisol Yoshiyu Takeda,* Isamu Miyamori, Takashi Yoneda, Kazuhiro Iki, Haruhiko Hatakeyama and Ryoyu Takeda Second Department of Internal Medicine, School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920, Japan T h e s e c r e t i o n o f a l d o s t e r o n e d e c l i n e s w i t h age. W e r e p o r t e d t h a t s o d i u m d e p l e t i o n i n c r e a s e d u r i n a r y e x c r e t i o n o f 1 8 - h y d r o x y c o r t i s o l ( 1 8 - O H - F ) . T o e l u c i d a t e t h e e f f e c t o f a g i n g o n u r i n a r y e x c r e t i o n of 1 8 - O H - F , we m e a s u r e d u r i n a r y 1 8 - O H - F in 30 n o r m o t e n s i v e s u b j e c t s a g e d 20-70 y r . T h e r e w e r e significant negative correlations between age and urinary excretion of 18-OH-F or of aldosterone ( r = --0.49, r = --0.58, P < 0.05, r e s p e c t i v e l y ) b u t n o t o f u r i n a r y f r e e c o r t i s o l . T h e s e r e s u l t s s u g g e s t t h a t a n g i o t e n s i n m a y c o n t r i b u t e to c h r o n i c r e g u l a t i o n o f 1 8 - O H - F .
J. Steroid Biochem. Molec. Biol., Vol. 50, No. 3/4, pp. 167-168, 1994
INTRODUCTION
were collected repeatedly. At the same time serum and urinary creatinine were measured. Urinary excretion of aldosterone was measured by R I A after hydrolysis at p H 1 for 24 h [6]. Urinary 1 8 - O H - F was measured by R I A after purification of the urine extract by high performance liquid chromatography ( H P L C ) [7]. Urinary free cortisol (F) was measured by R I A after purification of the urine extract by H P L C [8]. P R A and plasma aldosterone were measured by R I A , as previously described [6]. T h e relationships between age and urinary 1 8 - O H F, aldosterone or free cortisol were analyzed by linear regression. Statistical significance was accepted at a level of P < 0.05.
T h e zona glomerulosa of the adrenal cortex contains a cytochrome P-450aldo (P-450c~8, P-450cmo) that transforms corticosterone to 18-hydroxycorticosterone and aldosterone [1]. T h i s enzyme also transforms 18-hydroxycortisol ( 1 8 - O H - F ) from cortisol [2]. T h e activity of cytochrome P-450a~do is regulated by angiotensin I I and potassium [3]. Aldosterone secretion declines with advancing age [4]. Plasma renin activity (PRA) is also decreased in elderly subjects [5]. We reported that sodium depletion increased urinary excretion of 1 8 - O H - F [6]. In order to clarify whether angiotensin may contribute to chronic regulation of 1 8 - O H - F , we investigated the effect of aging on the urinary excretion of 1 8 - O H - F in normal subjects.
RESULTS
EXPERIMENTAL
Figure 1 shows a significant negative correlation between age and urinary excretion of 1 8 - O H - F in normal subjects (r = - 0 . 4 9 , P < 0.05). N o significant correlation was found between age and urinary free cortisol (Fig. 2). Urinary excretion of aldosterone and plasma aldosterone concentration showed a significant negative correlation with age (r = - 0 . 5 8 , r = - 0 . 6 2 , P < 0.05, respectively). Basal P R A was decreased with aging (r = - 0.61, P < 0.05). Urinary sodium excretion was 182 + 52 mmol/day.
Study protocol T h i r t y urine samples from healthy m e m b e r s of the laboratory staff and their adult relatives (age range, 20-70 yr) were collected. T h e s e individuals were allowed an unrestricted diet, but all were advised to limit their daily sodium intake to 180 to 200 mmol/day. T h e y have no complications with endocrine disorder, renal disease, hepatic disease or hypertension. T h e y received no medical attention. T w e n t y - f o u r urinary samples
DISCUSSION 18-Hydroxycortisol ( 1 8 - O H - F ) was first isolated as the major free cortisol in the urine of patients with
*Correspondence to Y. Takeda. Received 7 Jan. 1994; accepted 7 Apr. 1994. 167
168
Yoshiyu Takeda et al. 1500o
5
•
lOOO-
r
0 49
.u_
o= o ==
500o
'' 20
' 30
4'0 Age
' 50
'' 60
7'0
(yr)
Fig. 1. C o r r e l a t i o n b e t w e e n age a n d u r i n a r y excretion of 18-hydroxycortisol (18-OH-F) in the n o r m a l subjects. A significant negative c o r r e l a t i o n (r = - - 0 . 4 9 , P <0.05) was observed.
"-~ 500"
~
250. •
eI
•
|
0
I
20
••
•
•
I
I
40
50
Age
t
el
50
7'0
(yr)
Fig. 2. C o r r e l a t i o n b e t w e e n age a n d u r i n a r y excretion of free cortisol (free F) in the n o r m a l subjects. No significant c o r r e l a t i o n was observed.
Conn's syndrome [9] and was reported to be elevated in the urine of patients with either Conn's adenoma [10] or the rare glucocorticoid-remediable hyperaldosteronism [11]. We reported that urinary 18-OH-F is a good marker to distinguish aldosterone-producing adenoma from idiopathic hyperaldosteronism [12]. Hegstad et al. [4] suggested that aldosterone secretion declines with advancing age and that the effect of age on aldosterone secretion is an important consideration when one evaluates older hypertensive patients for primary aldosteronism. In this study, urinary excretion of 18-OH-F decreased with aging. T h e effect of age on 18-OH-F secretion is as important a consideration as the effect on aldosterone secretion. PRA declines with advancing age in normotensive persons [5]. Hegstad et al. [4] suggests that this decrease in PRA with increasing age is likely to be the primary cause of the lower plasma aldosterone levels. 18-Hydroxycortisol is transformed from cortisol by cytochrome P450a~do, which synthesizes aldosterone from corticosterone and 18-hydroxycorticosterone [2]. Shibata et al. reported that cytochrome P450aldo is regulated by angiotensin II and potassium in rats [3]. In humans, urinary excretion of 18-OH-F is increased by sodium restriction [6], which suggests 18-OH-F is partly under the control
of the renin-angiotensin system. T h e decrease in angiotensin levels with aging may contribute to the fall in 18-OH-F levels. Yamakita et al. reported that 18-OH-F and 18-oxo-F levels increased by being in an upright position for 2 h and that this increase disappeared with treatment of dexamethasone [13]. T h e y concluded that 18-oxo-F and 18-OH-F were more dependent on A C T H regulation in an acute phase. Our results suggest that angiotensin may contribute to chronic regulation of 18-OH-F.
REFERENCES 1. Ogishima T., Mitani F. and Ishimura Y.: Isolation of aldosterone synthase cytochrome P-450 from zona glomerulosa mitochondria of rat adrenal cortex. J. Biol. Chem. 264 (1989) 10,935-10,938. 2. Kawamoto T., Mitsuuchi Y., Toda K., Yokoyama Y., Miyahara K., Miura S., Ohnishi T., Ichikawa Y., Nakao K., Imura H., Ulick S. and Shizuta Y.: Role of steroid 1 lfl-hydroxylase and steroid 18-hydroxylase in the biosynthesis of glucocorticoids and mineralocorticoids in humans. Proc. Natn. Acad. Sci. U.S.A. 89 (1992) 1458-1462. 3. Shibata H., Ogishima T., Mitani F., Suzuki H., Murakami M., Saruta T. and Ishimura Y.: Regulation of aldosterone synthase cytochrome P-450 in rat adrenals by angiotensin II and potassium. Endocrinology 128 (1991) 2534-2539. 4. Hegstad R., Brown R. D., Jiang N-S., Kao P., Weinshilboum R. M., Strong C. and Wisgerhof.: Aging and aldosterone. Am..7. Med. 74 (1983) 442--448. 5. Noth R. H., Kassman M. N., Tan S. Y., Fernandez-Czuz A. Jr. and Murlrow P. J.: Age and renin-aldosterone system. Arch. Intern. Med. 137 (1977) 1414-1417. 6. Takeda Y., Miyamori I., Takeda R., Lewicka S. and Vecsei P.: Effect of sodium restriction on urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone, newly identified mineralocorticoids in man. J. Clin. Endocr. Metab. 74 (1992) 1195-1197. 7. Miyamori I., Takeda Y., Takasaki H., Itoh Y., Iki K. and Takeda R.: Determination of urinary 18-hydroxycortisol in the diagnosis of primary aldosteronism. J. Endocr. Invest. 15 (1992) 19-24. 8. Takeda Y., Miyamori I., Karayalcin U. and Takeda R.: Influence of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, pravastatin, on corticosteroid metabolism in patients with heterozygous familial hypercholesterolemia. Hormone Res. 36 (1991) 75-77. 9. Chu M. D. and Ulick S.: Isolation and identification of 18-hydroxy-cortisol from the urine of patients with primary hyperaldosteronism..7. Biol. Chem. 257 (1982) 2218-2224. 10. Ulick S. and Chu M. D.: Hypersecretion of a new corticosteroid, 18-hydroxycortisol in two types of adrenocortical hypertension. Clin. Exp. Hypertens. A4 (1982) 1771-1776. 11. Davis J. R. E., Burt D., Corrie J. E. T., Edwards C. R. W. and Sheppard M. C.: Dexamethasone-suppressible hyperaldosteronism: studies on overproduction of 18-hydroxycortisol in three affected family members. Clin. Endocr. 29 (1988) 297-308. 12. Takeda Y., Miyamori I., Iki K., Takeda R. and Vecsei P.: Urinary excretion of 19-noraldosterone, 18,19-dihydroxycorticosterone and 18-hydroxy-19-norcorticosterone in patients with aldosterone-producing adenoma or idiopathic hyperaldosteronism. Acta. Endocr. 126 (1992) 484-488. 13. Yamakita N., Gomez-Sanchez C, E., Mune T., Yoshida H., Miyazaki S., Yasuda K. and Nakai T.: Regulation of 18-oxocortisol and 18-hydroxycortisol by the renin-angiotensin system and ACTH in man..7. Steroid Biochem. Molec. Biol. 46 (1993) 395-399.
Pergamon
Effect of A g i n g on U r i n a r y E x c r e t i o n of 18-Hydroxycortisol Yoshiyu Takeda,* Isamu Miyamori, Takashi Yoneda, Kazuhiro Iki, Haruhiko Hatakeyama and Ryoyu Takeda Second Department of Internal Medicine, School of Medicine, Kanazawa University, 13-1 Takara-machi, Kanazawa 920, Japan T h e s e c r e t i o n o f a l d o s t e r o n e d e c l i n e s w i t h age. W e r e p o r t e d t h a t s o d i u m d e p l e t i o n i n c r e a s e d u r i n a r y e x c r e t i o n o f 1 8 - h y d r o x y c o r t i s o l ( 1 8 - O H - F ) . T o e l u c i d a t e t h e e f f e c t o f a g i n g o n u r i n a r y e x c r e t i o n of 1 8 - O H - F , we m e a s u r e d u r i n a r y 1 8 - O H - F in 30 n o r m o t e n s i v e s u b j e c t s a g e d 20-70 y r . T h e r e w e r e significant negative correlations between age and urinary excretion of 18-OH-F or of aldosterone ( r = --0.49, r = --0.58, P < 0.05, r e s p e c t i v e l y ) b u t n o t o f u r i n a r y f r e e c o r t i s o l . T h e s e r e s u l t s s u g g e s t t h a t a n g i o t e n s i n m a y c o n t r i b u t e to c h r o n i c r e g u l a t i o n o f 1 8 - O H - F .
J. Steroid Biochem. Molec. Biol., Vol. 50, No. 3/4, pp. 167-168, 1994
INTRODUCTION
were collected repeatedly. At the same time serum and urinary creatinine were measured. Urinary excretion of aldosterone was measured by R I A after hydrolysis at p H 1 for 24 h [6]. Urinary 1 8 - O H - F was measured by R I A after purification of the urine extract by high performance liquid chromatography ( H P L C ) [7]. Urinary free cortisol (F) was measured by R I A after purification of the urine extract by H P L C [8]. P R A and plasma aldosterone were measured by R I A , as previously described [6]. T h e relationships between age and urinary 1 8 - O H F, aldosterone or free cortisol were analyzed by linear regression. Statistical significance was accepted at a level of P < 0.05.
T h e zona glomerulosa of the adrenal cortex contains a cytochrome P-450aldo (P-450c~8, P-450cmo) that transforms corticosterone to 18-hydroxycorticosterone and aldosterone [1]. T h i s enzyme also transforms 18-hydroxycortisol ( 1 8 - O H - F ) from cortisol [2]. T h e activity of cytochrome P-450a~do is regulated by angiotensin I I and potassium [3]. Aldosterone secretion declines with advancing age [4]. Plasma renin activity (PRA) is also decreased in elderly subjects [5]. We reported that sodium depletion increased urinary excretion of 1 8 - O H - F [6]. In order to clarify whether angiotensin may contribute to chronic regulation of 1 8 - O H - F , we investigated the effect of aging on the urinary excretion of 1 8 - O H - F in normal subjects.
RESULTS
EXPERIMENTAL
Figure 1 shows a significant negative correlation between age and urinary excretion of 1 8 - O H - F in normal subjects (r = - 0 . 4 9 , P < 0.05). N o significant correlation was found between age and urinary free cortisol (Fig. 2). Urinary excretion of aldosterone and plasma aldosterone concentration showed a significant negative correlation with age (r = - 0 . 5 8 , r = - 0 . 6 2 , P < 0.05, respectively). Basal P R A was decreased with aging (r = - 0.61, P < 0.05). Urinary sodium excretion was 182 + 52 mmol/day.
Study protocol T h i r t y urine samples from healthy m e m b e r s of the laboratory staff and their adult relatives (age range, 20-70 yr) were collected. T h e s e individuals were allowed an unrestricted diet, but all were advised to limit their daily sodium intake to 180 to 200 mmol/day. T h e y have no complications with endocrine disorder, renal disease, hepatic disease or hypertension. T h e y received no medical attention. T w e n t y - f o u r urinary samples
DISCUSSION 18-Hydroxycortisol ( 1 8 - O H - F ) was first isolated as the major free cortisol in the urine of patients with
*Correspondence to Y. Takeda. Received 7 Jan. 1994; accepted 7 Apr. 1994. 167
168
Yoshiyu Takeda et al. 1500o
5
•
lOOO-
r
0 49
.u_
o= o ==
500o
'' 20
' 30
4'0 Age
' 50
'' 60
7'0
(yr)
Fig. 1. C o r r e l a t i o n b e t w e e n age a n d u r i n a r y excretion of 18-hydroxycortisol (18-OH-F) in the n o r m a l subjects. A significant negative c o r r e l a t i o n (r = - - 0 . 4 9 , P <0.05) was observed.
"-~ 500"
~
250. •
eI
•
|
0
I
20
••
•
•
I
I
40
50
Age
t
el
50
7'0
(yr)
Fig. 2. C o r r e l a t i o n b e t w e e n age a n d u r i n a r y excretion of free cortisol (free F) in the n o r m a l subjects. No significant c o r r e l a t i o n was observed.
Conn's syndrome [9] and was reported to be elevated in the urine of patients with either Conn's adenoma [10] or the rare glucocorticoid-remediable hyperaldosteronism [11]. We reported that urinary 18-OH-F is a good marker to distinguish aldosterone-producing adenoma from idiopathic hyperaldosteronism [12]. Hegstad et al. [4] suggested that aldosterone secretion declines with advancing age and that the effect of age on aldosterone secretion is an important consideration when one evaluates older hypertensive patients for primary aldosteronism. In this study, urinary excretion of 18-OH-F decreased with aging. T h e effect of age on 18-OH-F secretion is as important a consideration as the effect on aldosterone secretion. PRA declines with advancing age in normotensive persons [5]. Hegstad et al. [4] suggests that this decrease in PRA with increasing age is likely to be the primary cause of the lower plasma aldosterone levels. 18-Hydroxycortisol is transformed from cortisol by cytochrome P450a~do, which synthesizes aldosterone from corticosterone and 18-hydroxycorticosterone [2]. Shibata et al. reported that cytochrome P450aldo is regulated by angiotensin II and potassium in rats [3]. In humans, urinary excretion of 18-OH-F is increased by sodium restriction [6], which suggests 18-OH-F is partly under the control
of the renin-angiotensin system. T h e decrease in angiotensin levels with aging may contribute to the fall in 18-OH-F levels. Yamakita et al. reported that 18-OH-F and 18-oxo-F levels increased by being in an upright position for 2 h and that this increase disappeared with treatment of dexamethasone [13]. T h e y concluded that 18-oxo-F and 18-OH-F were more dependent on A C T H regulation in an acute phase. Our results suggest that angiotensin may contribute to chronic regulation of 18-OH-F.
REFERENCES 1. Ogishima T., Mitani F. and Ishimura Y.: Isolation of aldosterone synthase cytochrome P-450 from zona glomerulosa mitochondria of rat adrenal cortex. J. Biol. Chem. 264 (1989) 10,935-10,938. 2. Kawamoto T., Mitsuuchi Y., Toda K., Yokoyama Y., Miyahara K., Miura S., Ohnishi T., Ichikawa Y., Nakao K., Imura H., Ulick S. and Shizuta Y.: Role of steroid 1 lfl-hydroxylase and steroid 18-hydroxylase in the biosynthesis of glucocorticoids and mineralocorticoids in humans. Proc. Natn. Acad. Sci. U.S.A. 89 (1992) 1458-1462. 3. Shibata H., Ogishima T., Mitani F., Suzuki H., Murakami M., Saruta T. and Ishimura Y.: Regulation of aldosterone synthase cytochrome P-450 in rat adrenals by angiotensin II and potassium. Endocrinology 128 (1991) 2534-2539. 4. Hegstad R., Brown R. D., Jiang N-S., Kao P., Weinshilboum R. M., Strong C. and Wisgerhof.: Aging and aldosterone. Am..7. Med. 74 (1983) 442--448. 5. Noth R. H., Kassman M. N., Tan S. Y., Fernandez-Czuz A. Jr. and Murlrow P. J.: Age and renin-aldosterone system. Arch. Intern. Med. 137 (1977) 1414-1417. 6. Takeda Y., Miyamori I., Takeda R., Lewicka S. and Vecsei P.: Effect of sodium restriction on urinary excretion of 19-noraldosterone and 18,19-dihydroxycorticosterone, newly identified mineralocorticoids in man. J. Clin. Endocr. Metab. 74 (1992) 1195-1197. 7. Miyamori I., Takeda Y., Takasaki H., Itoh Y., Iki K. and Takeda R.: Determination of urinary 18-hydroxycortisol in the diagnosis of primary aldosteronism. J. Endocr. Invest. 15 (1992) 19-24. 8. Takeda Y., Miyamori I., Karayalcin U. and Takeda R.: Influence of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, pravastatin, on corticosteroid metabolism in patients with heterozygous familial hypercholesterolemia. Hormone Res. 36 (1991) 75-77. 9. Chu M. D. and Ulick S.: Isolation and identification of 18-hydroxy-cortisol from the urine of patients with primary hyperaldosteronism..7. Biol. Chem. 257 (1982) 2218-2224. 10. Ulick S. and Chu M. D.: Hypersecretion of a new corticosteroid, 18-hydroxycortisol in two types of adrenocortical hypertension. Clin. Exp. Hypertens. A4 (1982) 1771-1776. 11. Davis J. R. E., Burt D., Corrie J. E. T., Edwards C. R. W. and Sheppard M. C.: Dexamethasone-suppressible hyperaldosteronism: studies on overproduction of 18-hydroxycortisol in three affected family members. Clin. Endocr. 29 (1988) 297-308. 12. Takeda Y., Miyamori I., Iki K., Takeda R. and Vecsei P.: Urinary excretion of 19-noraldosterone, 18,19-dihydroxycorticosterone and 18-hydroxy-19-norcorticosterone in patients with aldosterone-producing adenoma or idiopathic hyperaldosteronism. Acta. Endocr. 126 (1992) 484-488. 13. Yamakita N., Gomez-Sanchez C, E., Mune T., Yoshida H., Miyazaki S., Yasuda K. and Nakai T.: Regulation of 18-oxocortisol and 18-hydroxycortisol by the renin-angiotensin system and ACTH in man..7. Steroid Biochem. Molec. Biol. 46 (1993) 395-399.