1、 So unbound cortisol is filtered into the urine.Dexamethasone suppression testCortisol excess secretion,will rapidly exceed the available capacity of cortisol binding globulin.The possibility that a patient may have Cushings syndrome frequently arises because they are obese（肥胖的）or hypertensive.ANDRO
2、GEN EXCESShyponatraemia (低钠血症);A natural or synthetic steroid with aldosterone-like activity is called a mineralocorticoid(盐皮质激素).Dexamethasone suppression testleads to pathological sodium loss(病理性钠流失)by the kidneyAdrenal insufficiency Adrenal crisisADRENOCORTICAL PATHOPHYSIOLOGYPrimary adrenocortic
3、al insufficiency17-hydroxyprogesterone)are secreted in large amounts.Failure of the adrenal cortex to produce cortisol and aldosterone may be due to autoimmune or infiltrative diseases(浸润性疾病)(infiltrative carcinoma).All of the 21-hydroxylated steroids(21-羟化类固醇)have mineralocorticoid effects to varyi
4、ng degrees.CORTISOL皮质醇Primary adrenocortical insufficiencyHypothalamic secretion(下丘脑分Dehydration (脱水)（继发性肾上腺皮质功能不全）stimulation of the adrenal cortex(刺激肾上腺皮质)by synthetic ACTH(Synacthen)ADRENAL INSUFFICIENCY肾上腺（皮质）功能不全An initial blood sample will be taken to check the baseline level of cortisol(280-7
5、20nmol/l).negative feedback loops(负反馈途径).Determining the causeA prolonged excessive exposure of body tissues to cortisol or any other glucocorticoid results in Cushings syndrome(库欣综合征).ALDOSTERONE EXCESS2 mmol/L(hypoglycaemia)Adrenocortical insufficiency is rare but life-threatening.1mg of Dexametha
6、sone(地塞米松)taken at 23:00trauma(创伤）Insulin-induced hypoglycaemia testNausea 低钠血症低钠血症高钾血症高钾血症Adrenal crisis (肾上腺危象肾上腺危象)Infectionoperation stress trauma(创伤）创伤）life-threatening)脱水Adrenal insufficiencyFollowing are the causes of adrenal insufficiency低钠血症高钾血症排泄排泄 Synacthen is a synthetic analogue of ACTH
7、(合成ACTH类似物)There are two kind of Synacthen teststhe short Synacthen test the depot Synacthen testSynacthen tests in the diagnosis of adrenocortical insufficiencyAn initial blood sample will be taken to check the baseline level of cortisol(280-720nmol/l).0.25m g S yn acth e n i s a d m i n i s t e r
8、e d intravenously(iv injection)to stimulate your own body production of cortisol.A blood sample will be taken at 30 minutes and 60 minutes after the stimulation to measure the cortisol level.Normally,the resting value is within the reference range 280720nmol/l at 08:0010:00 Am.There should be an inc
9、rement of more than 200nmol/L after Synacthen the final value should be greater than 500 nmol/L.Diagnostic criteria of If a patient with an impaired response to the Synacthen test.An elevated ACTH concentration will confirm the diagnosis of primary adrenal failure in such a patient.Patients with equ
10、ivocal responses(不明不明确应答确应答)to the short Synacthen testafter stimulation of the adrenal cortex with depot Synacthen(long-acting material长效的长效的).the short Synacthen test may be retested.The depot Synacthen test This depot Synacthen is given intramuscularly(IM injection)for 3 days.On the fourth day a
11、short Synacthen test is carried out as before.If the normal criteria for the short Synacthen test are satisfied on the second testing,it is not primary but secondary adrenocortical insufficiency.Depot Synacthen test an excellent diagnostic test for adrenal insufficiency used to check the amount of c
12、ortisol in the body and how well it can produce It also indicates the ability of adrenal cortex to respond to ACTH.The HPA axis may be investigated by performing an insulin tolerance test(ITT)(胰岛素耐量试验胰岛素耐量试验).ITT is used in diagnosis of pituitary insufficiency(垂体机能减退垂体机能减退)which may lead to secondar
13、y failure of the adrenal cortex.Diagnosis of adrenocortical insufficiencySUMMARY(Adrenal insufficiency)Adrenocortical insufficiency is rare but life-threatening.Failure of the adrenal cortex to produce cortisol and aldosterone may be due to autoimmune or infiltrative diseases(浸润性疾病浸润性疾病)(infiltrativ
14、e carcinoma).The Synacthen test is used in diagnosis of primary adrenocortical failure.The insulin tolerance test is used in diagnosis of pituitary insufficiency which may lead to secondary failure of the adrenal cortex.SUMMARY(Adrenal insufficiency)HYPERFUNCTION OF THE ADRENAL CORTEX肾上腺皮质功能肾上腺皮质功能亢
15、进亢进 Hyperfunction of the adrenal cortex can be conveniently discussed in terms of the overproduction of the three main products:Cortisol (皮质醇皮质醇)Adrenal androgens (肾上腺雄激素肾上腺雄激素)Aldosterone (醛固酮醛固酮)Hyperfunction of the adrenal cortexCORTISOL EXCESS A prolonged excessive exposure of body tissues to co
16、rtisol or any other glucocorticoid results in Cushings syndrome(库欣综合征库欣综合征).It is one of the most difficult endocrine diagnoses to make.Cortisol excessThe main clinical features of Cushings syndrome Disorders of lipid metabolism Disorders of protein metabolism Disorders of glycometabolism Electrolyt
17、e disturbances Hypertension Breakdown of immune function sexual disturbance In any investigation of Cushings syndrome the clinician should ask two questions:Does the patient actually have Cushings syndrome?The possibility that a patient may have Cushings syndrome frequently arises because they are o
18、bese（肥胖的肥胖的）or hypertensive.Cortisol excessOnce the diagnosis of Cushings syndrome is established,then a second question may be asked:What is the cause of the excess cortical secretion?Cortisol excessDiagnosis of Cortisol excess（1）I a t r o g e n i c（医 源 性）（医 源 性）C u s h i n g s syndrome should be diagnosed from the patient history and clinical examination(the steroid may have been taken)Cortisol excess secretion,will rapidly exceed the available capacity of cortisol binding globulin.皮质醇增多症皮质醇增多症
