The Adrenal Glands PartⅠ The Adrenal medulla Ziying WANG Institute of Pharmacology School of Medicine, Shandong University [email protected] n
Jan 12, 2016
The Adrenal Glands PartⅠThe Adrenal medulla
Ziying WANGInstitute of Pharmacology School of Medicine, Shandong [email protected]
Part 1 Introduction
Adrenal Glands
Blood supply
Nerve supply
AD
Embryology of the adrenal gland
Part 2 Adrenal medullaAt the interface between the neural
and endocrine system
Case: Mrs. Smith, a 45-year-old woman
• Worried for panic attacks– Sweating – Palpitation– Sudden episodes of rapid heart beating– Frightened
• Examination– Pale– P: 100/min– BP: 155/105 to 260-165 mmHg
• Investigation– Serum sodium: 141mmol/L (→)– Serum potassium : 3.2mmol/L (↓)– Plasma noradrenaline: 12nmol/L (↑ ↑)– Plasma adrenaline: 6.7nmol/L (↑ ↑ ↑ ↑)
Adrenal medulla
• Composed of polygonal cells arranged in cords or cluster
• Numerous wide diameter capillaries
• Sympathetic ganglion
Adrenal medulla chromate salt stain
– Brownish cytoplasm granules- when fixed by chromate salt containing fixative
– Also called chromaffin cell
Hormones of adrenal medulla
Catecholamines
Adrenaline
Noradrenaline
Dopamine
Peptides
Opiate peptides
Adrenomedullin
Arginine vasopressin
Vasoactive intestinal peptide
Catecholamine (CA)
Synthesis of catecholamine
Synthesis of catecholamine
• PNMT• Regulated by glucocorticoids.
Secretion of catecholamine
Regulation of catecholamine secretion
• The activity of the adrenal medulla is regulated by the activity of the sympathetic nerve.
Transport and metabolism of adrenal medullary hormones
(1) No specific binding proteins
(2) Onset rapid and short-lived
(3) Metabolized by COMT and MAO
(4) End product: VMA
Actions of adrenal medullary hormones
• Fight and flight neuroendocrine response
• Emergency reaction hypothesis:
W. B. Cannon, 1928
• Through activating adrenoceptors
Case: What is the cause?
Over-secretion of the CA
– Palpitation– Sudden episodes of rapid heart beating– Frightened– Pale– P: 100/min– BP: 155/105 to 260-165 mmHg– Plasma noradrenaline: 12nmol/L (↑ ↑)– Plasma adrenaline: 6.7nmol/L (↑ ↑ ↑ ↑)
Part 3 Disorders of the adrenal medulla
Phaeochromocytoma: a tumor causes
adrenal medullary hormones over-secretion
Phaeochromocytoma
Symptoms: with emergency reaction frequently
Diagnosis
(1) CT and MIBG: localization
(2) Symptoms: HBP, HG, high BMR
(3) VMA, AD and NA in urine
Treatment
(1) Operation
(2) Adrenoceptor antagonists• α-adrenoreceptor blockers• β-adrenoreceptor blockers
Case: treatment
(1) Drug treatment:α-blockers→β- blockers
(2) To find the source: CT and MIBG scan
(3) Operation
Familial Phaeochromocytoma
Part 3 Pharmacological uses of adrenal medullary hormones
Clinical uses of adrenaline
1. Cardiac arrest
2. Allergic shock: first choice
3. Bronchial asthma
4.Prolongation of local anesthetic duration
5. Topical hemorrhage
bronchial mucosa vessel dilation
↑HA, SRS, PGs, BK
Ag-Ab
Allergized cells
Bronchial SM contraction
dyspnea
Intrathoracic pressure↑
↓returned blood volume
↓SBP
Vessel dilation
DBP↓
mucosal edema
AD: first choice for allergic shock
AD
x
x xx
x
Clinical uses of NA
1. Shock and hypotension
2. Upper digestive tract hemorrhage
Endocrine hypertension
Belongs to secondary hypertension:
Conn’s syndrome
Cushing’s syndrome
Phaeochromocytoma