Disorders of adrenal (suprarenal) gland, stress.

Transcription

1 Disorders of adrenal (suprarenal) gland, stress.

2 Surgery/Endocrine/Adrenalectomy/Pages/Overview.aspx

3 Glucocorticoids CRH (from hypothalamus) Release stimulated by stress and hypoglycemia CRH is released in pulses Glucocorticoids have circadian rhytm (max. morning) Adrenal cortex hormones Functional tests: Dexamethasone Insulin, ACTH 24-hour urine collection

4 Adrenal cortex hormones RAAS Angiotensinogen RBF Renine ACE Mineralocorticoids Angiotensin I Angiotensin II Aldosterone Vazoconstriction Hyperkalemia Nečas Aldosterone

5 Adrenal cortex hormones Adrenal cortex hormones are synthetized from cholesterole In series of steps glucocorticoids, mineralocorticoids and androgens are created Enzymatic defects affect hormone production based on the site of defect

6 Disorders of adrenal cortex Congenital adrenal hyperplasia (21β-hydroxylase) Reduced production of gluco- a mineralocorticoids Feedback loop increases production of androgens (ACTH hyperplasia) virilization of neonate girls Non-classic form manifests in adulthood (virilization) (!) Reduced production of mineralocorticoids can be life-threatening (shock) Neonatal screening 17-OH progesterone Therapy: substitution of glucocorticoids and mineralocorticoids 11β-hydroxylase increased mineralocorticoid production (hypertension) 3β- hydroxydehydrogenase loss of strong androgens (testosterone)

7 Disorders of adrenal cortex Cushing s syndrome and Cushing s disease Causes: ACTH (Cushing s disease) pituitary adenoma, may have signs of hypopituitarism Adrenal cortisole (adenoma Cushing s syndrome) - atrophy of healthy parts of adrenal glands Ectopic production of ACTH (small cell lung cancer) Iatrogenic (immunosuppression)

8 Disorders of adrenal cortex Cushing s syndrome and Cushing s disease Steroid diabetes, hyperlipidemia Proteocatabolism: osteoporosis, striae, muscle atrophy, Fat redistribution (moon face, buffalo hump) Antiinflammatory effect, worse wound healing Hypertension (catecholamine sensibilization), atherosclerosis Peptic ulcers Androgennic effect in female ( SHBG), in male (LH inhibition) Steroid encephalopathy (emotional lability, depression)

9 Primary: Hyperaldosteronism Adrenal adenoma (Conn s syndrome), Hyperplasia (hypervolemia (hypertension), hypokalemia (fatigue, weakness, nephropathy, ileus), met. alcalosis (tetany), not edemas ANP contraregulation) Secondary: Shock (hypovolemic, distributive) Cardiac failure Ascites Disorders of adrenal cortex Renal and renovascular hypertension, nephrotic syndrome Bartter syndrome Without aldosterone : 11β-Hydroxysteroiddehydrogenase deficiency (AME) Liddle s syndrome Glucocorticoid remediable aldosteronism (GRA)

10 Disorders of adrenal cortex Adrenal insufficiency Addison s disease Adrenal insuficiency: enzymatic defects, autoimmune (APS), sepsis (Waterhouse- Friderichsen syndrome), ischemia (shock), Adrenal insuficiency POMC αmsh pigmentation ACTH deficiency ( white Addison) pituitary disorders, iatrogenic atrophy Mineralocorticoid deficiency Hypotonic dehydration (ortostatic hypotension, shock) Hyperkalemia (arrythmias), acidosis, (ADH-hyponatremia!glucose infusion!) glucose fever, lung edema

11 Disorders of adrenal cortex Adrenal insufficiency Addison s disease Glucocorticoid deficiency Hypoglycemia, inzuline lipolysis, protein catabolism GIT disorders nauzea, vomiting, loss of apetite Psychic alteration (lethargy) Central forms ( ACTH) only glucocorticoid deficiency (RAAS intact)

12 Disorders of adrenal cortex Addisonian crisis Hypotension, tachycardia circulatory shock Hypoglycemia hypoglycemic coma Hyperkalemia, hyponatremia, acidosis, nauzea, vomiting, diarrhea fever, apathy, confusion, neutropenia, lymphocytosis Triggered by trauma, infection, surgery (it is necessary to increase glucocorticoid doses in substitution therapies) Often iatrogenic cause in discontinuation of previous glucocorticoid treatment (down-regulation of receptors) + stress situation

13 Disorders of adrenal cortex Hypoaldosteronism Addison s disease Enyzmatic defects (some forms of CAH) - hyperreninemic hypoaldosteronism (aldosterone synthesis defect) Pseudohypoaldosteronism (aldosterone resistance) Hyporeninemic hypoaldosteronism (acquired defect of juxtaglomelural apparatus)

14 Disorders of adrenal cortex Androgens Determination of sex XY SRY XX Testes Ovarium Testosteron MIF absence of these Inner and outer genitalia Inner and outer genitalia Pubic hair Psychic Psychic Development periods: Fetal: Sexual development (Neonatal): Prepubertal: Suppression Pubertal: Puberty

15 Disorders of adrenal cortex Androgens Manifestation depends on gender, time of effect and type of disorder Increase (tumor (testes, adrenal gland), exogennic, adrenogenital syndrome) Pseudopubertas praecox (izo/heterosexualis) Virilization, hirsutism, amenorrhoea (adult females inc. Cushing s syndrome) Decrease (central, PRL, peripheral (testes), enzymatic defects, receptor) Androgen insensitivity syndrome (testicular feminization) Absence of puberty in male, late closure of epiphysis, Loss of pubic hair, libido in female BUT not in male if testes is normal Infertility of male (if testes production lost as well)

16 Stress Stress is uniform neurohumoral response of organism to being affected by stressor (an adverse condition). Stressor may be any adverse change of outer or inner conditions (physical wound, surgery; chemical intoxication; biological infection; psychic emotion, pain) Stage: Alarm reaction (Fight or flight): Catecholamines, glycogenolysis, lipolysis, proteocatabolism Resistance: Glucocorticoids, gluconeogenesis, proteocatabolism, antiinflamatory effects Exhaustion: Exhaustion of reserves

17 Stress Hypothalamo-pituitary-adrenal axis: brain cortex hypothalamus CRH (epinephrine release from hypothalamus) ACTH (and endorphins) glucocorticoids (and mineralocorticoids) suppression of TRH/TSH/T3,T4; STH increase Sympatoadrenal axis: hypothalamus spinal cord SNS catecholamines (neurocrine and endocrine effect)

18 Stress Sympathoadrenal system Develops from neural crest, controlled via nerves, stimulated by hypoglycemia Secretes catecholamines (epinephrine, norepineprhine, dopamine) Ca 2+ α 1 smooth muscle contraction (vazoconstriction) NE>E>D camp α 2 presynaptic inhibition, inzulin a glucagon camp β 1 cardiac (+ ino-,chrono-,dromotropic), renin E>NE>D Dobutamine camp β 2 smooth muscle relaxation (bronchodilation, tocolysis, vasodialtion glycogenolysis) Salbutamol camp β 3 lipolysis

19 Stress Alarm reaction: catecholamines most important, positive chrono-, ino- a dromotropic effect, CO, blood pressure increase, blood redistribution (!vazodilation in organs with β 2 receptors), increase blood clotting, glycogenolysis, lipolysis, bronchodilation Resistance: glucocorticoids most important, gluconeogenesis, proteocatabolism, antiinflamatory effect (counteracts SIRS), neutrophilia, decreased eozinophils and lymphocytes, fluid retention (blood loss) Importance of stress: adaptation vs. part of pathophysiology of diseases, psychoemotive stress does not provide advantage hypertension, atherosclerosis, hemoconcentration, CHD, stroke sympathicotonia Metabolic syndrome, infection, peptic ulcers, autoimmune disorders

20 Sympathetic hypofunction Adrenal medulla hypofunction only as part of whole sympathetic hypofunctions Autonomic failure (degeneration): orthostatic hypotension, thermoregulation disorders, sex function disorders, bronchoconstriction Horner s triad (eye): ptosis, miosis, apparent enopthalmos Impaired glucose counter-regulation: DM 1 st type, inadequate hormonal response to hypoglycemia (sympathetic system, glucagone) happens after previous episodes of hypoglycemia or with autonomic neuropathy

21 Disorders of adrenal medulla Pheochromocytoma: Paroxysmal hypertension, tachycardia and palpitations, headaches, chest pain, perspiration, hyperglycemia, constipation, heat intolerance, psychic disorders (unrest) Ratio of NE (hypertension) a E (tendency to hypotension) May be compensated receptor downregulation Diagnosis: urine metabolites (e.g. vanilmandelic acid) Complications: Intracranial hemorrhage, hypertensive nephro/retinopathy, arrhythmias, AMI May undergo necrosis imitates acute abdomen

22 Thank you for listening Sources: Obecná patologická fyziologie Nečas Patologická fyziologie orgánových systémů Část II Nečas Atlas patofyziologie člověka Silbernagl, Lang