Clinical biochemistry 2 - Essay Example

The biochemistry lab plays a vital role for an endocrinologist as well. Assessments of hormonal functions are important to provide for the diagnosis of endocrinology disorders and this is aided by the assistance of the biochemistry lab. The adrenal gland is one of the most important hormone secreting glands in the human body and the biochemistry laboratory plays a crucial role in the assessment of its function. The adrenal gland is responsible for the secretion of major hormones in the human body which include cortisol, epinephrine, norepinephrine as well as aldosterone.

Diseases affecting the gland can result in either overproduction or underproduction of these hormones and this can be tested via different laboratory tests. The hyper function of the adrenal gland can either lead to increased secretion of aldosterone resulting in the condition referred to as Conn’s syndrome or in the increased secretion of cortisol leading to Cushing’s syndrome. Cushing’s syndrome is led to by different causes which include either the increased secretion of ACTH by the anterior pituitary or from an ectopic site or owing to a primary carcinoma of the adrenal gland or an adrenal adenoma.

Biochemical tests can assist in reaching to a conclusion as to whether the disease is resulting due to a pathological condition of the gland itself or due to a secondary cause. . This test is referred to as the 24 hour Urinary Free Cortisol Test. After the laboratory result confirms the presence of increased cortisol, the levels of ACTH should be tested in the laboratory to confirm the fact if the increased cortisol secretion is due to the stimulation from ACTH. A blood sample should be taken after 4 p.m. to check for the levels of ACTH.

Increased cortisol due to a high level of ACTH is confirmed if the levels of ACTH are 2pg per mL. If the levels are below 5pg per mL, it confirms the fact that the adrenal gland is overactive and an underlying pathology of the gland exists. After these laboratory assessments, imaging techniques like MRI should be utilized for confirming the pathology of the adrenal gland. Conn’s syndrome which is the increased secretion of aldosterone can be tested by different laboratory investigations as well.

The levels of potassium, aldosterone and renin are checked to provide for a diagnostic evaluation of Conn’s syndrome. In this disease, low levels of potassium in the blood, high urinary potassium levels and a high aldosterone: renin ratio confirms the over activity of the adrenal gland. The levels of potassium are checked in the blood and potassium below 3mmol/l is seen in Conn’s syndrome. Urinary potassium over 24 hours is also tested and this level is raised above 30 mmol. The levels of aldosterone in the blood are checked and a level of above 250pmol/l is considered to be high.

If the disease is owing to adrenal gland hyperactivity, the aldosterone provides a negative feedback for renin and its levels are as low as 0.5pmol/ml/hour. If the levels of renin are also high along with aldosterone, this denotes that the disease is not arising from the adrenal gland. Thus a confirmatory