Plasma Cholinesterase Abnormalities Flashcards
What is plasma cholinesterase (PC)
An enzyme found in PLASMA and most TISSUES, but NOT in rbcs.
What does PC degrade
acetylcholine succinylcholine Ester-linked LA Cocaine Mivacurium Pilocarpine Donepezil
How is PC transmitted
Autosomal recessive
What chromosome is PC associated with
chromosome 3q26
What type of variant is assoc. with PC
Atypical
What aa change is noted for PC
70 Aspartine replaced by Glycine
What is the name of the test used to determine if a patient has PC
Dibucaine Number
How does the Dibucaine test work
The aa Dibucaine will inhibit the NORMAL PC activity by 80% in disease-free patients
The aa Dibucaine will inhibit ABNORMAL PC by only 20%
True/False
The Dibucaine test measures activity parameters such as PC plasma concentration and enzyme efficiency
FALSE
What is the genotype for someone with PC deficiency
EaEa
Some genetic variations are inhibited by
Fluoride
What are the genotypes for fluoride deficiencies
Ef
Es
What isoenzyme variant of PC results in abnormally rapid hydrolysis of succs
C5 variant
What is the Porphyrias
The porphyrias are a group of rare inherited or acquired disorders of certain enzymes that normally participate in the production of porphyrins and heme
porphyrins are the main precursors of heme, an essential constituent of hemoglobin, myoglobin, catalase, peroxidase, respiratory and P450 liver cytochromes.
What are the two categories of porphyrias
hepatic
erthropoietic
Hepatic porphyrias are further classifed into which four conditions
**Acute intermittent prophyria
Porphyria cutanea tarda
Variegate porphria
Hereditary coproporphyria
Which hepatic porphyria is the most important and serious form
Acute intermittent porphyria
In AIP deficiency of uroporphyrinogen I synthetase results in
excess formation of porphobilinogen and simga-aminolevulinate which accumulates in the urine
The clinical manifestations of AIP include
SEVERE abdominal pain in young-middle aged females
*mistaken for acute cholecystitis, pancreatitis, appendicitis, or renal colic
Demyelination»motor weakness, ANS dysfunction, emotional disturbances, psychosis, paralysis of resp. muscles
What events trigger attacks
starvation dehydration sepsis female hormones drugs
What drug classifications are known to precipitate porphyria
sedative/hypnotics-barb,ket,eto,benz analgesics-lidocaine anticonvulsants-phenytoin antibiotics-sulfa drugs steroids-Estrogen, Progesterones, corticost. toxins-ethanol, lead, amphetamines
GIve —– and —— only for patients with porphyria
opioids and propofol
Treatment of acute attacks of AIP
Hydration
Glucose infusion
Hematin infusion
Analgesia
