Although I have many more narrowly focused professional interests, I have decided to focus this professional blog on the field of pharmacodynamics because (1) I have a doctorate in pharmacodynamics and (2) I think that it is a broad enough topic and there will be many interesting things to talk about.
To begin, I will define pharmacodynamics. The simpliest definition that I have heard is that "pharmacodynamics is the study of what drugs do to be the body." The field of pharmacodynamics is often contrasted with the field of pharmacokinetics, which focuses on "what the body does to the drug," or how a drug is metabolized in the body.
Pharmacodynamics is really more than the study of what the drug does to the body because pharmacodynamics also focuses on the effects of natural hormones, neurotransmitters, etc, on body function.
Mathematically, the field of pharmacodynamics is frequently summarized as the relationship between the dose of a hormone or drug and the magnitude of the response that it creates.
Since receptor-based pharmacology is primarily based on a theory of direct correlation between drug-receptor binding and drug response, pharmacodynamics is also the study of the binding of hormone or drug to its receptors on the surface (0r in some cases within) of a cell.
Therefore, classic pharmacology textbooks describe pharmacodynamics as the mathematical relationship between a drug (L), the cell surface receptor (R), and the drug-receptor complex (LR):
Specifically, the relationship can be defined as:
Kd is equal to the equilibrium constant. , or the concentration of drug required to bind to 50% of the available receptors. Kd is typically defined as the affinity of the hormone or drug for its receptor. In other words, the Kd refers to the "tightness" of binding between the hormone or drug and its receptor.
One, of the hormones that we study is my lab is angiotensin II. Here are some data of the binding of this hormone to membranes prepared from the cortex of the adrenal gland:
The Kd would be the concentration at which 50% of the maximal binding occurs.
The open circles show binding in rats that have their ovaries removed, and the triangles show binding in ovariectomized rats have been treated with estrogen.
In the old days, it was common to transform this information into a format that could be expressed in a linear graph. This was done mostly because it is much easier to create a good linear graph than it is to create a good fit to a saturation isotherm. If you are a student of pharmacology, you have no doubt heard of these linear plots which are better known as "Scatchard" (or some would say more accurately known as "Rosenthal") plots.
Here's an example of that binding data from above in a linear Scatchard or Rosenthal plot:
In this plot, the X-intercept defines the maximal binding, and the slope of the line is equal to -1/Kd.
In summary, the goal of pharmacodynamics is to understand the relationship between a dose of a hormone or a drug and its response.
What will this blog be about?
My specialty is really adrenal endocrinology. You have probably heard that the adrenal gland gets activated during stress. The hormone "adrenalin", or epinephrine, is produced by the medulla of the adrenal gland. So, I will talk a lot about the hormones produced by the adrenal gland and their relationship to the metabolic (e.g. obesity), cardiovascular (e.g. hypertension), and cognitive and psychological effects of these hormones.
One of my other interests is in understanding differences between males and females, so this blog will discuss differences in the actions of many hormones and drugs in males and females and in females during pregnancy.
But this blog will not just be about stress and sex. This blog will also tackle interesting articles from the news as they pertain to the field of pharmacodynamics.
To begin, I will define pharmacodynamics. The simpliest definition that I have heard is that "pharmacodynamics is the study of what drugs do to be the body." The field of pharmacodynamics is often contrasted with the field of pharmacokinetics, which focuses on "what the body does to the drug," or how a drug is metabolized in the body.
Pharmacodynamics is really more than the study of what the drug does to the body because pharmacodynamics also focuses on the effects of natural hormones, neurotransmitters, etc, on body function.
Mathematically, the field of pharmacodynamics is frequently summarized as the relationship between the dose of a hormone or drug and the magnitude of the response that it creates.
Since receptor-based pharmacology is primarily based on a theory of direct correlation between drug-receptor binding and drug response, pharmacodynamics is also the study of the binding of hormone or drug to its receptors on the surface (0r in some cases within) of a cell.
Therefore, classic pharmacology textbooks describe pharmacodynamics as the mathematical relationship between a drug (L), the cell surface receptor (R), and the drug-receptor complex (LR):
Specifically, the relationship can be defined as:
Kd is equal to the equilibrium constant. , or the concentration of drug required to bind to 50% of the available receptors. Kd is typically defined as the affinity of the hormone or drug for its receptor. In other words, the Kd refers to the "tightness" of binding between the hormone or drug and its receptor.
One, of the hormones that we study is my lab is angiotensin II. Here are some data of the binding of this hormone to membranes prepared from the cortex of the adrenal gland:
The Kd would be the concentration at which 50% of the maximal binding occurs.
The open circles show binding in rats that have their ovaries removed, and the triangles show binding in ovariectomized rats have been treated with estrogen.
In the old days, it was common to transform this information into a format that could be expressed in a linear graph. This was done mostly because it is much easier to create a good linear graph than it is to create a good fit to a saturation isotherm. If you are a student of pharmacology, you have no doubt heard of these linear plots which are better known as "Scatchard" (or some would say more accurately known as "Rosenthal") plots.
Here's an example of that binding data from above in a linear Scatchard or Rosenthal plot:
In this plot, the X-intercept defines the maximal binding, and the slope of the line is equal to -1/Kd.
In summary, the goal of pharmacodynamics is to understand the relationship between a dose of a hormone or a drug and its response.
What will this blog be about?
My specialty is really adrenal endocrinology. You have probably heard that the adrenal gland gets activated during stress. The hormone "adrenalin", or epinephrine, is produced by the medulla of the adrenal gland. So, I will talk a lot about the hormones produced by the adrenal gland and their relationship to the metabolic (e.g. obesity), cardiovascular (e.g. hypertension), and cognitive and psychological effects of these hormones.
One of my other interests is in understanding differences between males and females, so this blog will discuss differences in the actions of many hormones and drugs in males and females and in females during pregnancy.
But this blog will not just be about stress and sex. This blog will also tackle interesting articles from the news as they pertain to the field of pharmacodynamics.
