Wingfield 1

Aceangiotensinconverbngenzyme aldosterone

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Unformatted text preview: Some hormones of the gastro-intestinal tract (uptake of ions and water). Autonomic nervous system and epinephrine (alpha and beta adrenergic receptors). Kidney
 Here is a normal adult kidney. The capsule has been removed. The hilum at the mid left contains some adipose tissue. Juxtaglomerular
cells
secrete
 renin
 Mammalian
renin:
an
enzyme
 A
fall
in
blood
pressure
(1)
causes
the
release
of
renin‐‐a
kidney
enzyme.
 Renin
(2)
in
turn
acBvates
angiotensin
(3),
a
hormone
that
causes
the
muscular

 walls
of
the
small
arteries
(arterioles)
to
constrict,
increasing
blood
pressure.
 Angiotensin
also
triggers
the
release
of
the
hormone
aldosterone
from
the
adrenal

 gland
(4),
that
causes
the
kidney
to
retain
salt
(sodium)
and
excrete
potassium.
The

 Sodium
retains
water,
expanding
the
blood
volume
and
increasing
blood
pressure.
 AcBons
of
the
renin‐angiotensin
II‐
 aldosterone
system
 Causes
smooth
muscles
in
arterioles
to
constrict
–
increasing

 
blood
pressure.

 Can
decrease
blood
flow
through
the
glomerulus
of
the
kidney.

 Acts
in
the
brain
to
regulate
thirst
(increases
drinking).
 Promotes
synthesis
and
secreBon
of
aldosterone
by
the
adrenal

 
cortex.
 Aldosterone
regulates
sodium
retenBon
and
potassium
excreBon
in

 
kidney.
 Aldosterone
promotes
sodium
uptake
in
the
G.I.
tract.
 Aldosterone
acts
on
brain
to
promote
sodium
appeBte
(salt
licks).
 Angiotensin
pepBdes
 Amino‐acid
sequences
of
angiotensin
pepBdes
and
the
receptor
 subtypes
with
which
they
interact.
The
ten‐amino‐acid
sequence
of
 the
precursor,
angiotensin
I,
is
shown
at
the
top,
with
the
amino
 acids
present
in
angiotensin
II
shown
in
red.
The
receptor
subtypes
 that
interact
with
each
pepBde
are
shown
on
the
right.
 A
change
in
the
ions
presented
to
the
Macula
Densa

 may
result
in
excess
ion
is
probably
sodium
or

 chloride.
Here
it
is
assumed
to
be
sodium.
 JG
Cell...
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This note was uploaded on 01/06/2010 for the course NPB idk taught by Professor Wingfield during the Spring '09 term at UC Davis.

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