Teratology II Flashcards
4 Factors affecting fetal dose
- Nature of agent itself
- Route and degree of maternal exposure
- Rate of placental transfer
- Composition of the maternal and embryonic/ fetal genotypes
What are 3 parts of the nature of the agent to consider?
Molecular Weight (size)
Charge - ionized forms do not cross the placenta
Pharmacokinetics
What are 3 important aspects of pharmacokinetics?
Systemic absorption
Plasma half-life
Protein binding- bound vs unbound
- bound drugs do not cross the placental barrier
What affect does bloodflow have on the effect of teratogen?
Faster blood flow the greater chance of teratogen being transfered from dam to fetus
3 important environmental factors?
Radiation
Chemical factors
Hormones
4 possible consequence of radiation
Preimplantation
Chromosome/fragmentation
DNA damage/mutations
Grwoth impairment
What is a consistent outcome of glucorticoids
Cleft Palate
Effect of glucorticoids on fetus
Effect metabolism which impedes cell function
Target of aspirin?
Inhibition of cyclooxygenase enzyme
What does aspirins affect on cyclooxygenase affect?
Break down of aracadonic acid into prostaglandins
What are prostaglandins important for?
Produce inflamation
Important in smooth muslce
Important in parturition
What does albendazole target?
Inhibits microtubule formation
-leads to cell arrest and cytoskeleton disruption
Embryological effects of Albendazole
External and skeletal malformation
Fused vertebra and ribs
Spina bifida
Decreased fetal weights
Vascular anomalies
Sulphonamides mode of action?
Structural analog of PABA
PABA used by bacteria to form follic acid
Why do sulphonamides affect horse development
Depend upon bacterial production of follic acid for nutrition
Follic acid important in proper development of rapidly deviding cells
