cardio drugs

Question 1

effects of AT1R?

Answer 1

PLC –> IP3 and DAG –> *PKC –> Ca2+ from SR/LTCC –> *MLCK –> contraction

Question 2

Effects of aldosterone

Answer 2

Upregulate Na+/K+ pump (3:2)
Upregulate eNaCs
Cl- reabsorbed

Question 3

Name of renin inhibitor?

Answer 3

Aliskiren

Question 4

Structure voltage gated ion channels?

Answer 4

a1 subunit and 3 auxilliary subunits. a1 = 4 homologous domains with 6 transmembrane alpha-helices - cation selective pores.
Auxilliary regulate a1 activity

Question 5

LTCC blockers?

Answer 5

Verapamil = phenylalkamine (cardioselective)
Amlodpipine = dihydropridine (vascular)

Question 6

TTCC blockers?

Answer 6

Mibefradil

Proliferation/hypertrophy?

Question 7

Diuretics?

Answer 7

Loop - inhibit Na/K/Cl carrier molecules by binding to Cl= site
Thiazide - less potent. Inhibit Na/Cl symporter at distal tubule.
K sparing - inhibits aldosterone mediated regulation of Na/K pump and eNaC expression (or block eNaC - amiloride)

Question 8

Organic nitrates

Answer 8

Preload - dilate veins
Afterload - dilate large resistance arteries

NO –> *guanylate cycase –> cGMP –> inhibts Ca2+ entry –> relaxation
Activates K+ channels - relaxation
cGMP dependent protein kinase (PKC) –> *MLC phosphatase –> dephosphorylates MLC -> relaxation

Question 9

K+ channel activators

Answer 9

Acts via NO –> myosin phosphatase –> dephosphorylation of MLC
Hyperpolarisation –> decrease in LTCCs –> decrease calcium