pH Buffer And Vehicles Flashcards
What is the relevance of pH to biological systems?
Most enzymatic actions occur at an optimal pH- changes in pH can alter the efficiency of an enzyme
Some ion channels are gated H+
The activity if some ion channels is altered by changes in pH
What is pH?
The activity of hydrogen ions in solution
What is the pH at which most mammalian cell lines have optimal growth?
pH of 7.4
What single pH range in which most mammalian cells can normally survive?
6.6-7.8
What pH is the blood?
7.35-7.45
What are used as a buffering agents?
HEPES and sodium bicarbonate
What is the pH used in brain slice experiments?
7.3-7.4
What is the pH of the ileum?
7-8
What is the pH of jejunum?
7-9
What is the significance of Ringers Solution?
The saline developed by Ringers can essentially compensate for lost blood serum and provide short term survival of tissues and cells
What does ringers solution contain?
Isotonic solution NaCL 6.5 g/L KCl 0.42 g/L CaCl2 0.25 g/L NaHCO3 0.2 g/L to balance pH
What is lactated ringers solution?
Isotonic solution which is a modification of ringers solution to treat acidosis in the blood NaCL 6g/L KCl 0.3 g/L CaCl2 0.2 g/L Sodium lactate 3.1 g/L
What does Tyrodes solution contain?
Isotonic solution similar to interstitial fluid and is a modification of lactated ringers solution . NaCl 8.0 g/L KCl 0.2 g/L NaHCO3 0.1 g/L NaH2PO4 0.1g/L MgCl2 0.1 g/L CaCl2 0.2 g/L Glucose 1.0 g/L
What is Krebs buffer?
Isotonic solution to study the heart and is a modification of ringers solution. Glucose 1.8 g/L MgCl2 0.0468 g/L KCl 0.34 g/L NaCl 7.0 g/L Sodium phosphate dibasic 0.1 g/L Sodium phosphate monobasic 0.18 g/L
What is a vehicle?
The solution the drug is dissolved in.
It carrys the drug to its destination (site of action)
Can be any salines
Can be used as the control for no drug comparison
