Objective—To evaluate adrenal sex hormone concentrations
in neutered dogs with hypercortisolemia.
Animals—11 neutered dogs with hypercortisolemia.
Procedure—Serum samples obtained before and 1
hour after administration of ACTH were evaluated for
concentrations of cortisol, progesterone, testosterone,
dehydroepiandrosterone sulfate or androstenedione
or both, and 17-hydroxyprogesterone.
Results—For all dogs, concentrations of 1 or more
adrenal sex hormones were substantially greater than
reference range values before or after administration
of ACTH. Testosterone concentration was not greater
than reference range values in any of the dogs.
Conclusions and Clinical Relevance—Results
emphasize the importance of ruling out hypercortisolemia
before measuring adrenal sex hormone concentrations
as a means of diagnosing adrenal hyperplasia
syndrome (alopecia X) in dogs. (J Am Vet Med Assoc 2001;218:214–216)
Objective—To compare the effects of 2 doses of
cosyntropin (5 µg/kg vs 250 µg, IV) on serum concentrations
of cortisol, sex hormones of adrenal origin,
and adrenocortical steroid intermediates and determine
the optimal sample collection time after adrenal
stimulation with cosyntropin.
Procedure—Dogs were randomly assigned to initially
receive cosyntropin at 5 µg/kg or as a total dose of
250 µg, IV. Dogs received the alternate dose 1 to 2
weeks later. Serum was obtained from blood samples
collected before (0 minutes) and 30, 60, 90, and 120
minutes after cosyntropin administration.
Results—Maximum stimulation of cortisol,
androstenedione, progesterone, and 17-hydroxyprogesterone
production was achieved at 60 minutes following
IV administration of cosyntropin at 5 µg/kg or
as a total dose of 250 µg. Serum estradiol concentration
did not increase in response to either cosyntropin
dose. For all hormones, no significant difference in
serum hormone concentrations was found among
sample collection times of 0, 30, 60, and 90 minutes
when comparing the 2 doses of cosyntropin.
Conclusions and Clinical Relevance—Cosyntropin,
when administered at 5 µg/kg, IV, effectively stimulated
maximum production of cortisol, sex hormones of
adrenal origin, and adrenocortical steroid intermediates
at 1 hour after administration. (Am J Vet Res
Objective—To investigate the in vitro effect of the combination of lignan enterolactone (ENL) or lignan enterodiol (END) with melatonin on steroid hormone secretion and cellular aromatase content in human adrenal carcinoma cells. Sample—Human adrenocortical carcinoma cells.
Procedures—Melatonin plus ENL or END was added to cell culture medium along with cAMP (100μM); control cells received cAMP alone. Medium and cell lysates were collected after 24 and 48 hours of cultivation. Samples of medium were analyzed for progesterone, 17-hydroxyprogesterone, androstenedione, aldosterone, estradiol, and cortisol concentration by use of radioimmunoassays. Cell lysates were used for western blot analysis of aromatase content.
Results—The addition of ENL or END with melatonin to cAMP-stimulated cells (treated cells) resulted in significant decreases in estradiol, androstenedione, and cortisol concentrations at 24 and 48 hours, compared with concentrations in cells stimulated with cAMP alone (cAMP control cells). The addition of these compounds to cAMP-stimulated cells also resulted in higher progesterone and 17-hydroxyprogesterone concentrations than in cAMP control cells; aldosterone concentration was not affected by treatments. Compared with the content in cAMP control cells, aromatase content in treated cells was significantly lower.
Conclusions and Clinical Relevance—The combination of lignan and melatonin affected steroid hormone secretion by acting directly on adrenal tumor cells. Results supported the concept that this combination may yield similar effects on steroid hormone secretion by the adrenal glands in dogs with typical and atypical hyperadrenocorticism.
Objective—To determine the effects of leuprolide
acetate, a long-acting gonadotropin-releasing hormone
analog, in ferrets with adrenocortical diseases.
Animals—20 ferrets with adrenocortical disease
diagnosed on the basis of clinical signs and plasma
sex hormone concentrations.
Procedure—Ferrets were treated with leuprolide
(100 µg, IM, once), and plasma hormone concentrations
were measured before and 3 to 6 weeks after
Results—Leuprolide treatment resulted in significant
reductions in plasma estradiol, 17 α-hydroxyprogesterone,
androstenedione, and dehydroepiandrosterone
concentrations and eliminated or reduced clinical
signs associated with adrenocortical disease.
Decreases in vulvar swelling, pruritus, and undesirable
sexual behaviors and aggression were evident 14
days after treatment; hair regrowth was evident by 4
weeks after treatment. The response to treatment
was transitory, and clinical signs recurred in all ferrets.
Mean ± SEM time to recurrence was 3.7 ± 0.4
months (range, 1.5 to 8 months).
Conclusions and Clinical Relevance—Results suggest
that leuprolide can be safely used to temporarily
eliminate clinical signs and reduce sex hormone concentrations
in ferrets with adrenocortical diseases.
However, the safety of long-term leuprolide use in ferrets
has not been investigated, and the long-term
effects of leuprolide in ferrets with nodular adrenal
gland hyperplasia or adrenal gland tumors are
unknown. (J Am Vet Med Assoc 2001;218:1272–1274)
Objective—To evaluate the clinical and endocrine
responses of ferrets with adrenocortical disease
(ACD) to treatment with a slow-release implant of
Animals—15 ferrets with ACD.
Procedure—Ferrets were treated SC with a single
slow-release, 3-mg implant of deslorelin acetate.
Plasma estradiol, androstenedione, and 17-hydroxyprogesterone
concentrations were measured before
and after treatment and at relapse of clinical signs; at
that time, the adrenal glands were grossly or ultrasonographically
measured and affected glands that
were surgically removed were examined histologically.
Results—Compared with findings before deslorelin
treatment, vulvar swelling, pruritus, sexual behaviors,
and aggression were significantly decreased or eliminated
within 14 days of implantation; hair regrowth
was evident 4 to 6 weeks after treatment. Within 1
month of treatment, plasma hormone concentrations
significantly decreased and remained decreased until
clinical relapse. Mean time to recurrence of clinical
signs was 13.7 ± 3.5 months (range, 8.5 to 20.5
months). In 5 ferrets, large palpable tumors developed
within 2 months of clinical relapse; 3 of these
ferrets were euthanatized because of adrenal gland
tumor metastasis to the liver or tumor necrosis.
Conclusions and Clinical Relevance—In ferrets with
ACD, a slow-release deslorelin implant appears
promising as a treatment to temporarily eliminate clinical
signs and decrease plasma steroid hormone concentrations.
Deslorelin may not decrease adrenal
tumor growth in some treated ferrets. Deslorelin
implants may be useful in the long-term management
of hormone-induced sequelae in ferrets with ACD and
in treatment of animals that are considered at surgical
or anesthetic risk. (Am J Vet Res 2005;66:910–914)
Objective—To characterize the physiologic response
to IV bolus injection of glucose and insulin for development
of a combined glucose-insulin test (CGIT) in
Animals—6 healthy mares and 1 mare each with
pituitary adenoma and urolithiasis.
Procedure—Horses were given a CGIT (glucose,
150 mg/kg; insulin, 0.1 U/kg); results were compared
with a singular IV glucose tolerance test (GTT; 150
mg/kg) and a singular IV insulin sensitivity test (IST;
0.1 U/kg). Healthy horses were also given a CGIT after
receiving xylazine and undergoing stress.
Results—Physiologically, the CGIT resulted in a 2-phase curve with positive (hyperglycemic) and negative
(hypoglycemic) portions; the positive phase came
first (250% of baseline at 1 minute). The descending
segment declined linearly to baseline by approximately
30 minutes and to a nadir at 58% of baseline
by 75 minutes. After a 35-minute valley, a linear
ascent to baseline began. Addition of insulin in the
CGIT increased glucose utilization by approximately
4.5 times during the positive phase but not during the
negative phase. The diseases' effects and experimental
inhibition of insulin secretion with xylazine and
stress were detectable by use of the 2 phases of the
CGIT. Only a single positive phase resulted from the
GTT and a single negative phase from the IST.
Conclusions and Clinical Relevance—The CGIT
resulted in a consistent, well-defined glycemia profile,
which can be disrupted experimentally or by a disease
process. The CGIT has clinical potential because it
provides integrated information and more information
than either the singular GTT or IST. (Am J Vet Res
Objective—To evaluate the effect of a soy-based diet on general health and adrenocortical and thyroid gland function in dogs.
Animals—20 healthy privately owned adult dogs.
Procedures—In a randomized controlled clinical trial, dogs were fed a soy-based diet with high (HID; n = 10) or low (LID; 10) isoflavones content. General health of dogs, clinicopathologic variables, and serum concentrations of adrenal gland and thyroid gland hormones were assessed before treatment was initiated and up to 1 year later. Differences between groups with respect to changes in the values of variables after treatment were assessed by means of a Student t test (2 time points) and repeated-measures ANOVA (3 time points).
Results—No differences were detected between the 2 groups with respect to body condition and results of hematologic, serum biochemical, and urine analyses. Most serum concentrations of hormones did not change significantly after treatment, nor were they affected by diet. However, the mean change in serum concentration of total thyroxine was higher in the HID group (15.7 pmol/L) than that in the LID group (–1.9 pmol/L). The mean change in estradiol concentration after ACTH stimulation at 1 year after diets began was also higher in the HID group (19.0 pg/mL) than that in the LID group (–5.6 pg/mL).
Conclusions and Clinical Relevance—Phytoestrogens may influence endocrine function in dogs. Feeding soy to dogs on a long-term basis may influence results of studies in which endocrine function is evaluated, although larger studies are needed to confirm this supposition.
Objective—To evaluate adrenal sex hormone concentrations
in response to ACTH stimulation in healthy
dogs, dogs with adrenal tumors, and dogs with pituitary-
dependent hyperadrenocorticism (PDH).
Animals—11 healthy control dogs, 9 dogs with
adrenal-dependent hyperadrenocorticism (adenocarcinoma
[ACA] or other tumor); 11 dogs with PDH, and
6 dogs with noncortisol-secreting adrenal tumors
Procedure—Hyperadrenocorticism was diagnosed on
the basis of clinical signs; physical examination findings;
and results of ACTH stimulation test, low-dose
dexamethasone suppression test, or both. Dogs with
noncortisol-secreting ATs did not have hyperadrenocorticism
but had ultrasonographic evidence of an AT.
Concentrations of cortisol, androstenedione, estradiol,
progesterone, testosterone, and 17-hydroxyprogesterone
were measured before and 1 hour after IM
administration of 0.25 mg of synthetic ACTH.
Results—All dogs with ACA, 10 dogs with PDH, and
4 dogs with ATs had 1 or more sex hormone concentrations
greater than the reference range after ACTH
stimulation. The absolute difference for progesterone,
17-hydroxyprogesterone, and testosterone concentrations
(value obtained after ACTH administration minus
value obtained before ACTH administration) was significantly
greater for dogs with ACA, compared with
the other 3 groups. The absolute difference for
androstenedione was significantly greater for dogs
with ACA, compared with dogs with AT and healthy
Conclusions and Clinical Relevance—Dogs with
ACA secrete increased concentrations of adrenal sex
hormones, compared with dogs with PDH, noncortisol-secreting ATs, and healthy dogs. Dogs with noncortisol-secreting ATs also have increased concentrations of sex hormones. There is great interdog variability
in sex hormone concentrations in dogs with ACA
after stimulation with ACTH. (J Am Vet Med Assoc
Objective—To determine causes of hyperphosphatasemia (high serum alkaline phosphatase [ALP] activity) in apparently healthy Scottish Terriers.
Design—Prospective case-controlled study.
Animals—34 apparently healthy adult Scottish Terriers (17 with and 17 without hyperphosphatasemia).
Procedures—Serum activities for 3 isoforms (bone, liver, and corticosteroid) of ALP were measured. Concentrations of cortisol, progesterone, 17-hydroxyprogesterone, androstenedione, estradiol, and aldosterone were measured before and after cosyntropin administration (ie, ACTH; 5 μg/kg [2.27 μg/lb], IM). Liver biopsy specimens from 16 dogs (11 with and 5 without hyperphosphatasemia) were evaluated histologically.
Results—In dogs with hyperphosphatasemia, the corticosteroid ALP isoform comprised a significantly higher percentage of total ALP activity, compared with the percentage in dogs without hyperphosphatasemia (mean ± SE, 69 ± 5.0% and 17 ± 3.8%, respectively). In 6 dogs with hyperphosphatasemia, but none without, serum cortisol concentrations exceeded reference intervals after ACTH stimulation. Six dogs with and 15 without hyperphosphatasemia had increased concentrations of ≥ 1 noncortisol steroid hormone after ACTH stimulation. Serum ALP activity was correlated with cortisol and androstenedione concentrations (r = 0.337 and 0.496, respectively) measured after ACTH stimulation. All dogs with and most without hyperphosphatasemia had abnormal hepatocellular reticulation typical of vacuolar hepatopathy. Subjectively, hepatocellular reticulation was more severe and widespread in hyperphosphatasemic dogs, compared with that in nonhyperphosphatasemic dogs.
Conclusions and Clinical Relevance—Hyperphosphatasemia in apparently healthy Scottish Terriers was most likely attributable to hyperadrenocorticism on the basis of exaggerated serum biochemical responses to ACTH administration and histologic hepatic changes, but none of the dogs had clinical signs of hyperadrenocorticism.