PS, PI, and PG pt 2 Flashcards

1
Q

what are ehter linked lipids

A

Ether-linked lipids are primarily a
specialized group of PL that account for
~20% of all of the classes of PL in vivo

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2
Q

ether linked lipids structure

A

The ether-linked lipids have an ether bond
in the sn-1 position that can also be
accompanied without (termed plasmanyl)
or with (termed plasmalogen) a 1′ cis
double bond
– An ether with a 1′ cis double bond is better
known as a vinyl ether
`

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3
Q

absence of ether linked lipids

A

To an individual cell, the absence of ether-
linked lipids is not lethal
* However, the absence of ether-linked
lipids is detrimental to tissues

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4
Q

disruptions of ether linked lipids in mice

A

Disruption of their synthesis in mice leads to
impaired neurological and eye development

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5
Q

disruption of ether linked lipids in humans

A

In humans, extremely rare genetic defects in
ether-linked lipid synthesis leads to impaired
brain development, rhizomelia (truncated limb
bones), and infantile death

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6
Q

where are ether linked lipids found

A

Ether-linked lipids exist in many tissues and in the plasma via lipoproteins
* Of interest:
– Tissues typically have ethanolamine plasmalogens, but the heart has a disproportionately higher amount of choline plasmalogens vs. ethanolamine plasmalogens
– 10% of PL on lipoproteins are ethanolamine based… 1/2 of
this is ethanolamine plasmalogen via ONLY the liver (a tissue with one of the lowest levels of plasmalogens)

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7
Q

what does the synth of ether linked lipids require

A

The synthesis of ether-linked lipids
requires fatty alcohols
– Fatty alcohols are also precursors for the
formation of most waxes

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8
Q

what are the two types of acyl CoA reductases that exist

A

– Acyl-CoA reductase 1
– Acyl-CoA reductase 2

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9
Q

what does acyl coa reductase 1 do

A

Acyl-CoA reductase 1 primarily reduces
C16 and C 18 unsaturated fatty acids

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10
Q

what does acyl coa reducatase 2 do

A

Acyl-CoA reductase 2 reduces all
saturated fatty acids

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11
Q

what does CDP-ethanolamine: 1alkyl-2-acyl-sn-glycerol ethanolaminephoshpotransferase do

A

attaches ethanoamine to phosphate

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12
Q

what does CDP- choline:1-alkyl-sn-glycerol cholinephosphotransferase do

A

attatches choline to phosphate

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13
Q

what is plasmanyl do

A

plasmanylethanolamine

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14
Q

wat is plasmalogen

A

ethanolamine plasmalogen

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15
Q

what is PAF- and what is it produced by

A

platelet activating factor
PAF is a plasmanylcholine produced by
endothelial cells and various white blood
cells (basophils, neutrophils, monocytes,
macrophages, mast cells)

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16
Q

what does PAF do

A

PAF triggers extremely potent pathological
responses associated with asthma,
hypertension, inflammation, allergic
responses, and anaphalaxis with as little
as 100 pM in the bloodstream

17
Q

how is PAF synthesized

A

remodelling route
de novo route

18
Q

remodelling route of PAF synth

A

Remodeling route: activated by inflammatory
events & primary route for pathogenesis
* The fatty acid in the sn-2 position of
plasmanylcholine is rapidly replaced with acetate

19
Q

de novo route of PAF synth

A

De novo route: maintains minimal
concentrations to regulate normal cellular
functions
* Synthesized over several steps starting with a
lyso-plasmanyl acid

20
Q

PAF and bronchoconstriction

A

increase

21
Q

PAF and pulmonary resistance

A

increase

22
Q

PAF and lung compliance

A

decrease

23
Q

PAF and pulmonary edema

A

increase

24
Q

PAF and hypertension

A

increase

25
Q

PAF and heart rate

A

increase

26
Q

PAF and hypersensitivity

A

increase

27
Q

PAF and intracellular [Ca++]

A

increase

28
Q

PAF and superoxide synth

A

increase

29
Q

PAF and eicosanoid synth from arachidonate

A

increase

30
Q

PAF and phosphoinositude utilization

A

increase

31
Q

PAF and pro-inflammatory cytokine synth

A

increase

32
Q

PAF and anti inflammatory cytokine synth

A

decrease

33
Q

what are the functions of plasmalogens

A

Not really clear, but current studies
suggest:
– Plasmalogens are typically enriched with
PUFAs, thus they are believed to act as a
supply of essential fatty acids during dietary
fatty acid deficiency
– It is also believed that the vinyl ether bond
acts as an antioxidant to scavenge damaging
reactive oxygen species

34
Q
A