| Sažetak | Hiperadrenokorticizam je vrlo česta endokrinološka bolest pasa. To je višesustavni organski
poremećaj koji nastaje zbog kronično povišene koncentracije glukokortikoida, hormona koje
u krv izlučuje kora nadbubrežne žlijezde. Naziva se još i Cushingov sindrom i
hiperkortizolizam.
Nadbubrežne žlijezde se sastoje od dva embriološki i funkcionalno odvojena dijela, kore i
srži.Kora nadbubrežne žlijezde je funkcionalno i strukturalno odvojena od srži, a dijeli se na
tri različite zone od kojih svaka izlučuje različitu skupinu hormona;zona arcuata sintetizira
mineralokortikoide, zona fasciculataglukokortikoide, dok zona reticularis izlučuje androgene
hormone. Mineralokortikoidi reguliraju koncentraciju elektrolita i vode u organizmu,
glukokortikoidi potiču glukoneogenezu te sudjeluju u metabolizmu bjelančevina i masti, a
imaju i protuupalno djelovanje.Funkciju kore nadbubrežne žlijezde reguliraju CRH i ACTH
podrijetlom iz hipotalamusa i adenohipofize.
Hiperadrenokorticizam može nastati spontano ili ijatrogeno. Kad govorimo o spontanom
hiperadrenokorticizmu tu ubrajamo hiperadrenokorticizam ovisan o hipofizi i
hiperadrenokorticizam ovisan o nadbubrežnoj žlijezdi. Hiperadrenokorticizam ovisan o
hipofizi najčešći je uzrok spontanog hiperadrenokorticizma u pasa, a pojavljuje se u 80-85%
slučajeva. Hiperadrenokorticizam ovisan o nadbubrežnoj žlijezdi zahvaća preostalih 15-20%
pasa. Ijatrogeni se hiperadrenokorticizam pojavljuje zbog prekomjerne uporabe
glukokortikoida u kontroli alergijskih ili imunološki posredovanih poremećaja. Određene
pasmine pasa su predisponirane za razvoj Cushingovog sindroma, te je pojavnost veća u
kastriranih ženki. Hiperadrenokorticizam se javlja najčešće kod starijih pasa, posebice kod
manjih pasmina.
Klinička slika ove bolesti je vrlo raznolika. Psi najčešće pokazuju kombinaciju nekoliko
najčešćih kliničkih znakova: polidipsija i poliurija, polifagija, povećanje obujma abdomena,
povećanje jetre, slabost i atrofija mišića, letargija i slabo podnošenje tjelesne aktivnosti,
patološke promjene na koži,alopecija, izostanak spolnog ciklusa u kuja ili atrofija testisa u
pasa, kalcinoza kože, miotonija, neurološki znakovi te na kraju hipertenzivna retinopatija.
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Postoje razni načini za dijagnostiku ove bolesti, a to su: pomoću hematologije, biokemijskog
profila i analize urina, pomoću slikovne dijagnostike (RTG, UZV, CT, MR) te pomoću
dijagnostičkih endokrinoloških testova. Najveću ulogu u dijagnostici imaju UZV abdomena te
CT/MR glave, no definitivna se dijagnoza postiže kombinacijom hormonskog testa i slikovne
dijagnostike.
Hiperadrenokorticizam ovisan o hipofizi se liječi najčešće medikamentno (pomoću trilostana
ili mitotana) te se može liječiti i zračenjem ili kirurški ali to su rijetki slučajevi.
Hiperadrenokorticizam ovisan o nadbubrežnoj žlijezdi liječi se medikamentno (pomoću
trilostana ili mitotana) ili kirurški.
Prognoza bolesti je dobra kod hiperadrenokorticizma ovisnog o hipofizi, ako se liječi pravilno
medikamentno i ako se lezija ne proširi toliko da stvara druge komplikacije, psi tad mogu
preživjeti godinama. Kod hiperadrenokorticizma ovisnog o nadbubrežnoj žlijezdi je prognoza
odlična ako se tumor uspije u potpunosti ukloniti i ako nije metastazirao. Kod neoperabilnih
tumora je prognoza također dobra ako se liječi mitotanom ili nešto lošija ukoliko se liječi
trilostanom. Prognoza Cushingove bolesti u pasa je povoljna i uz odgovarajuću terapiju psi
mogu živjeti godinama s dobrom kvalitetom života. |
| Sažetak (engleski) | Cushing's disease is a very common endocrine disease in dogs. It is a multiple organ
dysfunction caused by chronically elevated concentration of glucocorticoids, hormones that
are secreted into the bloodstream by the adrenal cortex. The disease is also known as
Cushing's syndrome or hypercortisolism.
The adrenal gland functionally and embryologically comprises two distinct parts, a cortex and
a medulla. The cortex itself, which is functionally and structurally divided from the medulla.
is subdivided into three zones, all of which produce different types of hormones: the zona
arcuata is responsible for the synthesis of mineralocorticoids, the zona fasciculata synthesizes
and secrets glucocorticoids, while the zona reticularis produces hormones called androgens.
Mineralocorticoids help regulate electrolytes and water balance in the body; glucocorticoids,
which stimulate gluconeogenesis, are involved in the metabolism of proteins and fats, while at
the same time having anti-inflammatory effects. The function of the adrenal cortex is
regulated by CRH and ACTH, the former originating from hypothalamus and the latter from
adenohypophysis.
Hyperadrenocorticism in dogs may occur spontaneously or may be iatrogenic. Spontaneously
occuring hyperadrenocorticism is classified as: pituitary-dependent hyperadrenocorticism and
adrenal-dependent hyperadrenocorticism. Pituitary-dependent hyperadrenocorticism is the
most common form of spontaneous hyperadrenocorticism in dogs and accounts for 80 – 85 %
of cases in dogs. Adrenal-dependent hyperadrenocorticism affects the remaining 15 – 20 % of
dogs. Iatrogenic hyperadrenocorticism is caused by excessive administration of
glucocorticoids used in regulation of allergies and autoimmune diseases. Certain breeds of
dogs are more prone to develop Cushing's syndrome and a slightly greater incidence has been
found in spayed female dogs.
Hyperadrenocorticism is most commonly diagnosed in older dogs, especially in small breed
dogs.
Clinical manifestations of this disease are numerous and veriable. The most common
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symptoms include the combination of the following clinical signs: polydipsia and polyuria,
polyphagia, abdominal distention, liver enlargement, weakness and muscle atrophy, letarghy
and reduced physical activity, pathological skin changes, alopecia, failure to cycle in female
dogs or testicular atrophy in male dogs, calcinosis cutis, myotonia, neurological signs and
finally hypertensive retinopathy.
There are different ways used to diagnose this disease, such as hematology tests, biochemical
profile tests and urinanalysis, diagnostic imaging (X – rays, USG, CT, MRI), and
endocrinology tests. Abdominal US and cranial CT/MRI scans have the most important role
in its diagnosis, but the final diagnosis is made by the combination of screening
endocrinological blood tests and diagnostic imaging.
Pituitary-dependent hyperadrenocorticism is mostly treated medically with either trilostane or
mitotane, but it can also be treated with radiation therapy or surgically. However, the latter
two treatments are very rare. Adrenal-dependent hyperadrenocorticism is usually treated
medically (by trilostane or mitotane), or surgically.
The prognosis of patients with pituitary-dependent hyperadrenocorticism is very good if
treated with correctly determined medication, and if a lesion does not expand to such an
extent that it creates other complications. In that case, dogs can live for many years. The
prognosis of patients with adrenal-dependent hyperadrenocorticism is excellent if tumor has
been completely removed and has not metastasized. In case of inoperable tumors, if the
disease is treated with mitotane, the prognosis is also good, and the prognosis is somewhat
poorer if the disease is treated with trilostane. The prognosis of patients with Cushing's
disease is favourable, and with an appropriate treatment dogs may live long and have a goodquality
life. |
