From the Guidelines
Beta 2 adrenoreceptor stimulation causes hyperlactatemia primarily through increased glycogenolysis and lactate production in skeletal muscles. This occurs as stimulation of β-adrenergic receptors in skeletal muscles activates glycogenolysis and lactate production via the formation of cyclic AMP, due to the absence of glucose-6-phosphatase in these tissues 1. The key mechanism involves the activation of enzymes that break down glycogen, leading to an increase in glucose availability, which is then converted into pyruvate through glycolysis. As the rate of pyruvate production exceeds the mitochondrial capacity to metabolize it, more pyruvate is converted to lactate, resulting in hyperlactatemia. Some of the key points to consider include:
- The role of cyclic AMP in mediating the effects of β-adrenergic stimulation on glycogenolysis and lactate production
- The specific involvement of skeletal muscles in lactate production due to their lack of glucose-6-phosphatase
- The clinical implications of β-adrenergic stimulation, such as the use of epinephrine, which can lead to a transient increase in serum lactate levels, although this is often non-clinically relevant 1. In clinical practice, understanding the metabolic effects of vasoactive agents like β-adrenergic agonists is crucial for managing patients, especially those in critical care settings, to monitor and interpret changes in lactate levels appropriately.
From the Research
Mechanism of Beta 2 Adrenoreceptor Stimulation
- Beta 2 adrenoreceptor stimulation leads to increased aerobic glycolysis, resulting in lactate formation 2
- This mechanism is involved in lactate production during shock states, including septic shock, low cardiac output states, and hemorrhagic shock 2
- Epinephrine stimulation, possibly through beta 2 adrenoreceptor involvement, contributes to lactate production in muscle tissue 2
Role of Adrenergic Stimulation
- Adrenergic stimulation, particularly through beta 2 adrenoreceptors, plays a key role in stress hyperlactataemia 3
- Increased lactate production is associated with adrenergic stimulation, which facilitates bioenergetic efficiency in muscle and other organs 3
- Beta 2 adrenoreceptor activation induces cyclic AMP, leading to various intracellular signaling pathways, including those involved in lactate production 4
Hyperlactatemia and Lactic Acidosis
- Medication-induced hyperlactatemia and lactic acidosis can occur due to various medications, including beta 2 agonists like epinephrine and albuterol 5
- Beta 2 agonists can cause lactate level elevations, which can be classified as lactic acidosis or hyperlactatemia 5
- The fall in plasma magnesium and the possible role of beta 2 agonists in the production of lactic acidosis are also discussed in the context of metabolic effects of beta 2 agonists 6