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Urinary excretion of free tyramine and of norepinephrine and its metabolites in unipolar depressed patients
BIOL PSYCHIATRY 1986;21:221-224
Brief Reports
221
Urinary Excretion of Free Tyramine and of Norepinephrine and Its Metabolites in Unipolar Depressed Patients Alec Roy, Markku Linnoila, Farouk Karoum, and David Pickar
Introduction In a recent study of the urinary excretion of norephinephrine (NE) and its major metabolites, we found that unipolar depressed patients had a significantly raised urinary excretion of NE and no~etaneph~ne (NM) when compared with normal controls (Roy et al. 1986b). Similarly, the National Institute of Mental Health Collaborative Program also recently reported that unipolar depressed patients had a significantly raised urinary excretion of both NE and NM compared with controls (Koslow et al. 1983). We have also compared depressed patients and controls for a ratio indicative of the relative activity of the major metabolic pathways for NE. In the depressed patients, the urinary excretion of NE and NM, deriving from the major extraneuronal pathway, formed a significantly greater percent of the sum of the urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) and vanillylmandelic acid (VMA), which are the metabolites most representative of total NE metabolism (Roy et al, 1986a). This finding suggests that there is a shift in depression to greater use of extraneuronal metabolic path-
ways for NE and its metabolites. There are a number of possible explanations for this finding, one of which, examined here, is that high circulating levels of the indirect-acting sympathomimetic amine tyramine release excess NE in the depressed patients, thus shifting NE metabolism away from intraneuronal routes. Depressed patients, particularly those with melancholia, have been shown to excrete significantly smaller amounts of conjugated tyramine than controls (Sandler et al. 1975; Bonham Carter et al. 1978, 1980; Harrison et al. 1984). It has also been suggested that tyramine may have a role in the regulation of NE turnover, as its excretion rate was found to correlate with 24-hr “wholebody” NE turnover in depressed patients (Linnoila et al. 1982). Thus, the purpose of this study was to test the hypothesis that the increased urinary excretion of NE and NM in depressed patients might be due to altered tyramine metabolism, by comparing depressed patients and controls for their urinary excretion of free tyramine and by examining for inte~elationships between the urinary excretion of free tyramine and of NE and its metabolites.
FromtheSection on Clinical Studies, Clinical Neuroscience Branch (A.R., D.P.) and the Adult Psychiatry Branch (F.K.), NIMH, and tbe National Institute on A&&o1 Abuse and AlcohoIism, DICBR. Laboratory of Clinical Studies, Washington, DC Address reprint requests to Alec Roy, M.B., Section on Clinica Studies, Clinical Neuroscience Branch, National Institute of Mental Health, Bldg. 10, Rm. 4N214, 9OKl Rockville Pike, Washington, D.C. 202OS-IOOO. Received June 27, 1985; revised August 10, 1985.
Methods Twelve depressed inpatients were studied and compared with 25 normal controls. After a clinical interview, the depressed patients were diagnosed using the diagnostic criteria DSM-III
222
EWL PSYCHIATRY lYX6.21:221 -224
( 1980). They consisted of eight patients with a major depressive episode (MDE) and melancholia and four MDE patients who had had melancholia during a previous episode. For all the depressed patients, the 2 1-item Hamilton Rating Scale for Depression (Hamilton 1960) was completed All controls were interviewed with the Schedule for Affective Disorders and Schizophrenia (SADS-L) (Endicott and Spitzer 1979) to exclude a psychiatric disorder, and none had a family or past history of a psychiatric disorder. The controls were physically well. were taking no medication, had a normal physical examination, chest x-ray, and electrocardiogram (EKG), and had normal routine blood test results. The controls were studied as outpatients. Patients and normal controls followed a lowmonoamine, alcohol-free, and caffeine-restricted diet during the study. All depressed patients who were taking psychotropic medications were slowly withdrawn from medications and were medication-free for at least 2 weeks prior to study. Two 24-hr urine samples (7:00 AM to 7:00 AM) were collected into 3% sodium bisulfite, and ahquots were kept frozen at - 20°C until analyzed. Only samples with a volume in excess of 900 ml were accepted for the study. Free urinary tyramine, total urinary norepinephrine (NE), normetanephrine (NM), 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid (VMA) concentrations were measured with mass fragmentography after hydrolysis of conjugates (Karoum and Neff 1982). For each patient and control, we expressed the mean urinary excretion rate for NE and each of its three major metabolites in molar units per 24 hr. The sum of NE and its metabolites was used as an indicator of “whole-body” NE tumover. The following ratio was calculated and (NE + NM)/ a percent: expressed as (MHPG + VMA). It indicates a ratio of the sum of the two extraneuronally derived metabolites, NE and NM. to the sum of the two NE metabolites most representative of total NE metabolism, MHPG and VMA. Statistical analysis was by Student’s r-test
Brief Reports
with two-tailed probabilities method of correlation.
and
Pearson’s
Results The clinical and descriptive data for the depressed patients and normal controls are shown in Table 1. There was no significant difference between the depressed patients and normal controls for the urinary excretion of free tyramine (423.0 t 177.8 pg/24 hr versus 425.4 ? 149.6 pg/24 hr, t = 0.04, NS). In the depressed patients, there were no significant correlations between urinary levels of tyramine and either NF or any of its metabolites or with 24-hr “wholebody” NE turnover or the ratio of NE metabolites. Among the normal controls, urinary levels of tyramine were significantly correlated with urinary levels of MHPG and NM (p < 0.009 and p < 0.03, respectively) (Table 2). We next combined the depressed and normal control groups (n = 37) to see whether or not other significant correlations would emerge in a larger sample. There were significant correlations between urinary levels of tyramine and
Table I Clinical Data and Rating Scale Score Normal control\
Mean age in
(n = 25, -_ 44.9 (23. 73)
year\ Male Female
IO 15
Mean duration of episode in months Mean number of previous episodes Mean age at onwt of disorder Mean Hamilton depression score Mean weeks medication-free
-.-.
Brief Reports
BIOL
223
PSYCHIATRY
1986;21:221-224
Table 2. Urinary Excretion Rate of Free Tyramine Correlated with Those of Norepinephrine and Its Major Metabolites in Unipolar Depressed Patients and Controls
Ttyamine Depressed patients (n = 12) Normal controls (n = 25) NE,
norepinephrine;
Numbers
are Pearson
“Sum”indicates “Ratio”
MHPG
NM
VMA
Sum
Ratio
0.42 0.19
0.41 0.47”
0.33 o.39b
0.34 0.18
0.38 0.30
0.20 0.06
3-methoxy-4-hydroxyphenylglycol;
NM,
normetanephrine;
VMA,
vanillylmandelic
acid.
correlation coefficients. + MHPCi
t
NM
+
indicates a ratio of the e~tra~uronall~
most representative “p i
NE
MHPG,
NE
VMA
(in molar units),
derived
metabolites
which NE
indicates “whole-body”
+ NM
to MHPG
+
VMA.
NE tomover. which are the two NE
metabolites
of total NE metabolism.
0.009.
“p < 0.03.
MHPG (r = 0.43,~ < 0.004), NM (1. = 0.27, p < 0.05), and the sum of NE meta~lites (r = 0.32, p < 0.03), and there were trends toward significant correlations for NE (r = 0.27, p < 0.07) and VMA (r = 0.23, p < 0.09). Discussion In the present study, there was no significant difference between unipolar depressed patients and normal controls for urinary levels of free tyramine, and there were no significant correlations among the depressed patients between the urinary excretion rates of tyramine and the urinary excretion rates of NE and its metabolites. Thus, these results suggest that the significantly higher urinary levels of NE and NM in depressed patients that we reported earlier are unlikely to be due to changes in tyramine metabolism. We followed the methodology of Linnoila et al. (1983), who have shown that at least two complete 24-hr urine samples are required in depressed patients on a low monoamine diet to obtain reliable info~ation about the excretion of NE and its metabolites. In this study, we considered only depressed inpatients who had severe recurrent unipolar affective disorder and who had major depressive episodes meeting DSM-III criteria for melancholia (“endogenous” depression), which is the subgroup of uni~l~ depressed patients who have been found to have significantly elevated levels of plasma and urine NE when compared with controls (Roy 1986b).
in an earlier study, Linnoila et al (1982) did fmd si~ificant correlations in depressed patients between urinary levels of tyramine and NE and its metabolites. However, that study did not include normal controls, and the depressed patients were mainly bipolar depressed patients, whereas all the patients in the present study were unipolar depressed patients. Fu~he~ore, some of the patients of Linnoila et al. (1982) had very high outputs of urinary free tyramine. This was reflected in the higher means and SDS as compared with the present results. In the present study, normal controls were also studied and significant correlations between urinary levels of tyramine and urinary levels of NE and MHPG were found. When the depressed patients and normal controls were combined, there was also a significant correlation between urinary levels of tyramine and the sum of NE and its metabelites, and trends toward significant correlations with urinary levels of NE and VMA. These results suggest that although the regulation of the urinary excretion of tyramine and NE and its metabolites may covary, any correlations that are found between them in uni~lar melancholic patients are probably not specific to depression. In summary, in the present study, we found that unipolar depressed patients and normal controls did not differ significantly on urinary tyramine levels and there were no significant correlations with urinary NE and its metabolites in the depressed patients. Thus, higher urinary levels of NE and its metabolites in unipolar depressed patients are probably not secondary to
224
BIOL PSYCHIATRY 1986:21:221-224
Brief Reports
changes in tyramine metabolism in depressive illness.
Thanks are due to Loann Drake for statistical help and Andrea Hobbs for secretarial help.
References American Psychiatric Association (I 980): Diagnostic and Statistical Manual of Mental Disorders, 3rd cd. Washington. DC: American Psychiatric Association. Bonham Carter S, Sandler M, Goodwin BL, Sepping P, Bridges PK (1978): Decreased urinary output of tyramine and its metabolites in depression. Br J Psychiatry 132:125-132. Bonham Carter SM. Reveley MA, Sandier M, Dewhurst J, Little B, Hayworth J, Priest R (1980): Decreased urinary output of conjugated tyramine is associated with lifetime vulnerability to depressive illness. Psychiatry Res 3: 13-2 1. Endicott J, Spitzer R (1979): A diagnostic interview: The Schedule for Affective Disorders and Schizophrenia. Arch Gen Psychiatry 35:837-844. Hamilton M (1960): A rating scale for depression. Neurol Neurosurg Psychiatry 2356-62.
J
Harrison W, Cooper T, Stewart J, Quitkin F, McGrath P, Liebowitz M, Rabkin J, Markowitz J, Klein D (I 984): The tyramine challenge test as a marker for melancholia. Arch Gen Psychiatr.v 41:681692.
Karoum F, Neff N (1982): Quantitative gas chromatography-mass spectrometry [GC-MS] of biogenie amines: theory and practice. In Spector S, Beck N (eds). Modern Methods in Pharmacoloav. <,, New York: klan R. Liss. Koslow S, Mass J, Bowden C, Davis JK, Hanin I, Javaid J (1983): CSF and urinary biogenic amines and metabolites in depression and mania. Arch Gan Psychiatry 40:999-1010. Linnoila M, Karoum F. Potter W (1982): High positive correlation between urinary free tyramine excretion rate and “whole body” norepinephrine turnover in depressed patients. Biol Psychiatq 17:1031-1036. Linnoila M, Karoum F. Miller T, Potter W (1983): Reliability of urinary monoamine and metabolite output measurements in depressed patients. Am J Psychiatry 140:1055-1057. Roy A, Pickar D, Linnoila M, Potter W (1985): Plasma norepinephrine in affective disorders: Relationships to melancholia. Arch Gen Psychiatr?; (in press), Roy A, Linnoila M. Karoum F, Pickar D (1986a): Relative activity of metabolic pathways for norepinephrine in endogenous depression. Acta Psychiatr Stand (submitted). Roy A, Pickar D, Douillet P, Karoum F. Linnoila M ( 1986b): Urinary monoamines and monamine metabolites in subtypes of unipolar depressive disorder and normal controls. Psycho/ Med (submitted). Sandler M, Bonham Carter S. Cuthbert MF, Pare C ( 1975): Is there an increase in monoamine oxidase activity in depressive illness? Luncet i:1045-1049.
Brief Reports
221
Urinary Excretion of Free Tyramine and of Norepinephrine and Its Metabolites in Unipolar Depressed Patients Alec Roy, Markku Linnoila, Farouk Karoum, and David Pickar
Introduction In a recent study of the urinary excretion of norephinephrine (NE) and its major metabolites, we found that unipolar depressed patients had a significantly raised urinary excretion of NE and no~etaneph~ne (NM) when compared with normal controls (Roy et al. 1986b). Similarly, the National Institute of Mental Health Collaborative Program also recently reported that unipolar depressed patients had a significantly raised urinary excretion of both NE and NM compared with controls (Koslow et al. 1983). We have also compared depressed patients and controls for a ratio indicative of the relative activity of the major metabolic pathways for NE. In the depressed patients, the urinary excretion of NE and NM, deriving from the major extraneuronal pathway, formed a significantly greater percent of the sum of the urinary excretion of 3-methoxy-4-hydroxyphenylglycol (MHPG) and vanillylmandelic acid (VMA), which are the metabolites most representative of total NE metabolism (Roy et al, 1986a). This finding suggests that there is a shift in depression to greater use of extraneuronal metabolic path-
ways for NE and its metabolites. There are a number of possible explanations for this finding, one of which, examined here, is that high circulating levels of the indirect-acting sympathomimetic amine tyramine release excess NE in the depressed patients, thus shifting NE metabolism away from intraneuronal routes. Depressed patients, particularly those with melancholia, have been shown to excrete significantly smaller amounts of conjugated tyramine than controls (Sandler et al. 1975; Bonham Carter et al. 1978, 1980; Harrison et al. 1984). It has also been suggested that tyramine may have a role in the regulation of NE turnover, as its excretion rate was found to correlate with 24-hr “wholebody” NE turnover in depressed patients (Linnoila et al. 1982). Thus, the purpose of this study was to test the hypothesis that the increased urinary excretion of NE and NM in depressed patients might be due to altered tyramine metabolism, by comparing depressed patients and controls for their urinary excretion of free tyramine and by examining for inte~elationships between the urinary excretion of free tyramine and of NE and its metabolites.
FromtheSection on Clinical Studies, Clinical Neuroscience Branch (A.R., D.P.) and the Adult Psychiatry Branch (F.K.), NIMH, and tbe National Institute on A&&o1 Abuse and AlcohoIism, DICBR. Laboratory of Clinical Studies, Washington, DC Address reprint requests to Alec Roy, M.B., Section on Clinica Studies, Clinical Neuroscience Branch, National Institute of Mental Health, Bldg. 10, Rm. 4N214, 9OKl Rockville Pike, Washington, D.C. 202OS-IOOO. Received June 27, 1985; revised August 10, 1985.
Methods Twelve depressed inpatients were studied and compared with 25 normal controls. After a clinical interview, the depressed patients were diagnosed using the diagnostic criteria DSM-III
222
EWL PSYCHIATRY lYX6.21:221 -224
( 1980). They consisted of eight patients with a major depressive episode (MDE) and melancholia and four MDE patients who had had melancholia during a previous episode. For all the depressed patients, the 2 1-item Hamilton Rating Scale for Depression (Hamilton 1960) was completed All controls were interviewed with the Schedule for Affective Disorders and Schizophrenia (SADS-L) (Endicott and Spitzer 1979) to exclude a psychiatric disorder, and none had a family or past history of a psychiatric disorder. The controls were physically well. were taking no medication, had a normal physical examination, chest x-ray, and electrocardiogram (EKG), and had normal routine blood test results. The controls were studied as outpatients. Patients and normal controls followed a lowmonoamine, alcohol-free, and caffeine-restricted diet during the study. All depressed patients who were taking psychotropic medications were slowly withdrawn from medications and were medication-free for at least 2 weeks prior to study. Two 24-hr urine samples (7:00 AM to 7:00 AM) were collected into 3% sodium bisulfite, and ahquots were kept frozen at - 20°C until analyzed. Only samples with a volume in excess of 900 ml were accepted for the study. Free urinary tyramine, total urinary norepinephrine (NE), normetanephrine (NM), 3-methoxy-4-hydroxyphenylglycol (MHPG), and vanillylmandelic acid (VMA) concentrations were measured with mass fragmentography after hydrolysis of conjugates (Karoum and Neff 1982). For each patient and control, we expressed the mean urinary excretion rate for NE and each of its three major metabolites in molar units per 24 hr. The sum of NE and its metabolites was used as an indicator of “whole-body” NE tumover. The following ratio was calculated and (NE + NM)/ a percent: expressed as (MHPG + VMA). It indicates a ratio of the sum of the two extraneuronally derived metabolites, NE and NM. to the sum of the two NE metabolites most representative of total NE metabolism, MHPG and VMA. Statistical analysis was by Student’s r-test
Brief Reports
with two-tailed probabilities method of correlation.
and
Pearson’s
Results The clinical and descriptive data for the depressed patients and normal controls are shown in Table 1. There was no significant difference between the depressed patients and normal controls for the urinary excretion of free tyramine (423.0 t 177.8 pg/24 hr versus 425.4 ? 149.6 pg/24 hr, t = 0.04, NS). In the depressed patients, there were no significant correlations between urinary levels of tyramine and either NF or any of its metabolites or with 24-hr “wholebody” NE turnover or the ratio of NE metabolites. Among the normal controls, urinary levels of tyramine were significantly correlated with urinary levels of MHPG and NM (p < 0.009 and p < 0.03, respectively) (Table 2). We next combined the depressed and normal control groups (n = 37) to see whether or not other significant correlations would emerge in a larger sample. There were significant correlations between urinary levels of tyramine and
Table I Clinical Data and Rating Scale Score Normal control\
Mean age in
(n = 25, -_ 44.9 (23. 73)
year\ Male Female
IO 15
Mean duration of episode in months Mean number of previous episodes Mean age at onwt of disorder Mean Hamilton depression score Mean weeks medication-free
-.-.
Brief Reports
BIOL
223
PSYCHIATRY
1986;21:221-224
Table 2. Urinary Excretion Rate of Free Tyramine Correlated with Those of Norepinephrine and Its Major Metabolites in Unipolar Depressed Patients and Controls
Ttyamine Depressed patients (n = 12) Normal controls (n = 25) NE,
norepinephrine;
Numbers
are Pearson
“Sum”indicates “Ratio”
MHPG
NM
VMA
Sum
Ratio
0.42 0.19
0.41 0.47”
0.33 o.39b
0.34 0.18
0.38 0.30
0.20 0.06
3-methoxy-4-hydroxyphenylglycol;
NM,
normetanephrine;
VMA,
vanillylmandelic
acid.
correlation coefficients. + MHPCi
t
NM
+
indicates a ratio of the e~tra~uronall~
most representative “p i
NE
MHPG,
NE
VMA
(in molar units),
derived
metabolites
which NE
indicates “whole-body”
+ NM
to MHPG
+
VMA.
NE tomover. which are the two NE
metabolites
of total NE metabolism.
0.009.
“p < 0.03.
MHPG (r = 0.43,~ < 0.004), NM (1. = 0.27, p < 0.05), and the sum of NE meta~lites (r = 0.32, p < 0.03), and there were trends toward significant correlations for NE (r = 0.27, p < 0.07) and VMA (r = 0.23, p < 0.09). Discussion In the present study, there was no significant difference between unipolar depressed patients and normal controls for urinary levels of free tyramine, and there were no significant correlations among the depressed patients between the urinary excretion rates of tyramine and the urinary excretion rates of NE and its metabolites. Thus, these results suggest that the significantly higher urinary levels of NE and NM in depressed patients that we reported earlier are unlikely to be due to changes in tyramine metabolism. We followed the methodology of Linnoila et al. (1983), who have shown that at least two complete 24-hr urine samples are required in depressed patients on a low monoamine diet to obtain reliable info~ation about the excretion of NE and its metabolites. In this study, we considered only depressed inpatients who had severe recurrent unipolar affective disorder and who had major depressive episodes meeting DSM-III criteria for melancholia (“endogenous” depression), which is the subgroup of uni~l~ depressed patients who have been found to have significantly elevated levels of plasma and urine NE when compared with controls (Roy 1986b).
in an earlier study, Linnoila et al (1982) did fmd si~ificant correlations in depressed patients between urinary levels of tyramine and NE and its metabolites. However, that study did not include normal controls, and the depressed patients were mainly bipolar depressed patients, whereas all the patients in the present study were unipolar depressed patients. Fu~he~ore, some of the patients of Linnoila et al. (1982) had very high outputs of urinary free tyramine. This was reflected in the higher means and SDS as compared with the present results. In the present study, normal controls were also studied and significant correlations between urinary levels of tyramine and urinary levels of NE and MHPG were found. When the depressed patients and normal controls were combined, there was also a significant correlation between urinary levels of tyramine and the sum of NE and its metabelites, and trends toward significant correlations with urinary levels of NE and VMA. These results suggest that although the regulation of the urinary excretion of tyramine and NE and its metabolites may covary, any correlations that are found between them in uni~lar melancholic patients are probably not specific to depression. In summary, in the present study, we found that unipolar depressed patients and normal controls did not differ significantly on urinary tyramine levels and there were no significant correlations with urinary NE and its metabolites in the depressed patients. Thus, higher urinary levels of NE and its metabolites in unipolar depressed patients are probably not secondary to
224
BIOL PSYCHIATRY 1986:21:221-224
Brief Reports
changes in tyramine metabolism in depressive illness.
Thanks are due to Loann Drake for statistical help and Andrea Hobbs for secretarial help.
References American Psychiatric Association (I 980): Diagnostic and Statistical Manual of Mental Disorders, 3rd cd. Washington. DC: American Psychiatric Association. Bonham Carter S, Sandler M, Goodwin BL, Sepping P, Bridges PK (1978): Decreased urinary output of tyramine and its metabolites in depression. Br J Psychiatry 132:125-132. Bonham Carter SM. Reveley MA, Sandier M, Dewhurst J, Little B, Hayworth J, Priest R (1980): Decreased urinary output of conjugated tyramine is associated with lifetime vulnerability to depressive illness. Psychiatry Res 3: 13-2 1. Endicott J, Spitzer R (1979): A diagnostic interview: The Schedule for Affective Disorders and Schizophrenia. Arch Gen Psychiatry 35:837-844. Hamilton M (1960): A rating scale for depression. Neurol Neurosurg Psychiatry 2356-62.
J
Harrison W, Cooper T, Stewart J, Quitkin F, McGrath P, Liebowitz M, Rabkin J, Markowitz J, Klein D (I 984): The tyramine challenge test as a marker for melancholia. Arch Gen Psychiatr.v 41:681692.
Karoum F, Neff N (1982): Quantitative gas chromatography-mass spectrometry [GC-MS] of biogenie amines: theory and practice. In Spector S, Beck N (eds). Modern Methods in Pharmacoloav. <,, New York: klan R. Liss. Koslow S, Mass J, Bowden C, Davis JK, Hanin I, Javaid J (1983): CSF and urinary biogenic amines and metabolites in depression and mania. Arch Gan Psychiatry 40:999-1010. Linnoila M, Karoum F. Potter W (1982): High positive correlation between urinary free tyramine excretion rate and “whole body” norepinephrine turnover in depressed patients. Biol Psychiatq 17:1031-1036. Linnoila M, Karoum F. Miller T, Potter W (1983): Reliability of urinary monoamine and metabolite output measurements in depressed patients. Am J Psychiatry 140:1055-1057. Roy A, Pickar D, Linnoila M, Potter W (1985): Plasma norepinephrine in affective disorders: Relationships to melancholia. Arch Gen Psychiatr?; (in press), Roy A, Linnoila M. Karoum F, Pickar D (1986a): Relative activity of metabolic pathways for norepinephrine in endogenous depression. Acta Psychiatr Stand (submitted). Roy A, Pickar D, Douillet P, Karoum F. Linnoila M ( 1986b): Urinary monoamines and monamine metabolites in subtypes of unipolar depressive disorder and normal controls. Psycho/ Med (submitted). Sandler M, Bonham Carter S. Cuthbert MF, Pare C ( 1975): Is there an increase in monoamine oxidase activity in depressive illness? Luncet i:1045-1049.