Composition of Breast Fluid of a Man with Galactorrhea and Hyperprolactinaemia*

Abstract

It has been previously reported that men with and without known disease can produce milk, but no studies to date have demonstrated that their secretion contains milk constituents produced specifically by the breast. The present study shows the presence of lactose, alpha-lactalbumin, and lactoferrin in the breast secretion of a 27-yr-old male who had galactorrhea associated with hyperprolactinaemia. The concentrations of lactose, proteins, and electrolytes in the breast secretion of this man are within the range of colostrum and milk obtained from normal lactating women.

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0021-972X/81/5203-0581$02.00/0
Journal of Clinical Endocrinology and Metabolism
Copyright©
1981
by The Endocrine Society
Vol.
52,
No.
3
Printed in U.S.A.
Composition of Breast Fluid of a Man with Galactorrhea
and Hyperprolactinaemia*
J. K. KULSKI, P. E. HARTMANN,
AND
D. H. GUTTERIDGE
Department of Biochemistry, University of Western Australia, and the Endocrinology Unit, Sir Charles
Gairdner Hospital, Nedlands,
6009,
Western Australia
ABSTRACT. It has been previously reported that men with
and without known disease can produce milk, but no studies to
date have demonstrated that their secretion contains milk con-
stituents produced specifically by the breast. The present study
shows the presence of lactose, a-lactalbumin, and lactoferrin in
the breast secretion of a 27-yr-old male who had galactorrhea
associated with hyperprolactinaemia. The concentrations of
lac-
tose,
proteins, and electrolytes in the breast secretion of this
man are within the range of colostrum and milk obtained from
normal lactating women. (J Clin Endocrinol Metab 52: 581,
1981)
M
OST studies on human milk composition have
been limited to the period of the initiation and
maintenance of normal lactation which is appropriate to
the needs of the newborn
(1,
2). However, lactation may
also occur at a time which is inappropriate to the physi-
ological status of either men or women, with or without
known endocrinopathies (3-6). In most reported cases,
the diagnosis of inappropriate lactation (galactorrhea)
has been based on the expression of breast fluid without
an analysis of its composition (3-6). In one study, the
breast secretion of a young man with hypogonadism and
galactorrhea was analyzed for the presence of triglycer-
ides,
cholesterol, and nitrogen, the levels reportedly were
in keeping with human female milk (7). However, no
study has yet demonstrated the presence of specific milk
constituents, such as lactose, a-lactalbumin, or casein, in
the breast secretion of men with clinical galactorrhea.
Therefore, the present study was undertaken to deter-
mine 1) whether the breast secretion of a man who had
galactorrhea associated with elevated levels of serum
PRL contained specific or nonspecific milk constituents
and 2) how the concentration of these constituents com-
pared to the levels in colostrum and milk of normal
lactating women.
Received August
11,
1980.
Address all correspondence and requests for reprints to: Dr. J. K.
Kulski, Department of Biomedical and Environmental Health Sciences,
School of Public Health, University of California, Berkeley, California
94720.
* This work was supported by a grant from the National Health and
Medical Research Council of Australia.
Subjects and Methods
A 27-yr-old man with galactorrhea and decreased potency
was studied. X-Rays and tomographs demonstrated an enlarged
pituitary fossa, and the concentrations of PRL, FSH, and LH
in his serum were 183 jug/liter (normal, <5 jUg/liter), 3 U/liter
(normal, 3-19 U/liter) and 8 U/liter (normal, 3-22 U/liter),
respectively. Samples of his breast secretion (0.2-1.0 ml) were
expressed manually directly into sterile polypropylene vials
once a month during a 3-month period of study.
Samples of breast secretion also were collected from 52
normal women. Colostrum was collected during the last trimes-
ter of pregnancy and day 1 post partum, and mature milk was
collected between 1-12 months post partum.
The breast fluids of the women and the man were analyzed
for the presence of lactose, total protein, a-lactalbumin, lacto-
ferrin, albumin, immunoglobulin A, Na, K, and Cl using assay
methods previously described (8).
Results and Discussion
The concentrations of lactose, proteins, and electro-
lytes in the colostrum and milk of normal lactating
women and in the breast secretion of a man with galac-
torrhea are shown in Table 1. The results show that the
male breast can synthesize and secrete specific milk
constituents, such as lactose and a-lactalbumin, at ap-
proximately the levels found in the colostrum and milk
of normal lactating women. In addition, the nonspecific
milk proteins (lactoferrin, immunoglobulin A, and albu-
min) and electrolytes in the breast secretion of the man
were at concentrations similar to those found in the
colostrum and milk of normal lactating women. In this
581
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582COMMENTS
JCE & M • 1981
Vol 52 • No 3
TABLE
1. Comparison between concentrations of milk constituents in
the breast secretion of a male with galactorrhea and the breast secretion
of women
Milk constitu-
ent
Lactose (g/100
ml)
Protein (g/100
ml)
a-Lactalbumin
(g/liter)
Lactoferrin (g/li-
ter)
Albumin (g/liter)
Immunoglobulin
A (g/liter)
Na (mM)
K (mM)
Cl (mM)
Male galactorrhea
Sam-
ple 1
4.1
6.23
4.31
18.0
3.0
9.2
39.0
15.0
37.0
Sam-
ple 2
4.6
5.37
4.21
13.0
4.5
9.9
36.3
16.0
35.0
Sam-
ple 3
6.3
1.65
2.92
5.1
1.5
2.0
14.0
21.0
17.0
Breast secretion from
women"
Colostrum
2.34 ± 0.65
6.83 ± 3.2
3.41 ± 0.89
22.8 ± 12.0
3.4 ± 1.7
9.74 ± 6.4
61.9 ± 16.0
14.5 ± 5.1
56.3 ± 62.0
Milk
6.6 ± 0.62
1.4 ± 0.9
1.8 ± 0.42
1.2 ± 0.46
0.4 ± 0.08
0.95 ± 0.2
8.3 ± 6.4
13.4 ± 20.3
11.8 ± 3.8
Colostrum was collected during late pregnancy and 1 day post
partum, and the milk was colllected during established lactation be-
tween 1-12 months post partum.
" Mean ±
SD.
man, the synthesis and secretion of milk was related to
pituitary dysfunction and high levels of serum PRL, a
hormone known to play an important role in the initia-
tion and maintenance of lactation in humans (9) and
other species (10).
Only one previous report has stressed the importance
of defining abnormal breast fluid as milk on the basis of
its content of a specific milk constituent (6). Lactose, a-
lactalbumin (which functions as one component in lac-
tose synthase for the production of lactose), and casein
are the only milk constituents known to be synthesized
specifically by the mammary gland (11,12). The analysis
of inappropriate breast discharges for these constituents
offers a more specific demonstration that the fluid se-
creted is milk. In this connection, further studies of the
composition of normal and inappropriate breast secre-
tions may help to provide a better understanding of the
factors controlling the complex process of lactation, par-
ticularly if such studies are related to the hormone levels
in the blood and mammary secretion (13-15) as well as
to diagnosed endocrine disorders.
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