Question

Octreotide is correctly described by which of the following statements? (A) It is identical to naturally occurring somatostatin. (B) It is used to treat growth hormone deficiency. (C) It is administered orally. (D) It is a more potent inhibitor of growth hormone secretion than is somatostatin. (E) It contains more than 100 amino acids.

Short answer

(D) It is a more potent inhibitor of growth hormone secretion than somatostatin.

Step-by-step solution

Identify the Nature of Octreotide

Octreotide is a synthetic analog of the naturally occurring hormone somatostatin. Unlike somatostatin, octreotide is not identical but designed to mimic and enhance certain properties of somatostatin.

Determine Administration Route

Octreotide is not administered orally due to its peptide nature, which makes it susceptible to degradation in the gastrointestinal tract. Instead, it is typically given via injection.

Evaluate Its Potency Compared to Somatostatin

Octreotide is known to be a more potent inhibitor of growth hormone secretion compared to natural somatostatin. This is one of its therapeutic benefits, allowing for more effective treatment of conditions like acromegaly.

Assess Its Amino Acid Count

Octreotide is made up of 8 amino acids, which is significantly fewer than many naturally occurring peptides like somatostatin, which has 14, or typical proteins like insulin.

Review Its Primary Use

Octreotide is primarily used to treat conditions related to excessive hormone secretion, such as acromegaly, and not typically for growth hormone deficiency.

Key concepts

Octreotide

Octreotide is a laboratory-created compound that acts similarly to the natural hormone somatostatin. Unlike somatostatin, which is naturally occurring in the body, octreotide is synthesized to enhance and mimic specific functions of somatostatin. By modulating these functions, octreotide is valuable in medical treatments. Unlike typical oral medications, octreotide cannot be taken through the mouth. This is because it is a peptide, which means it would break down in the digestive system before having a chance to work.

Instead, octreotide is usually delivered through injections, allowing it to remain stable and active as it circulates throughout the body. This is particularly important for treating disorders like acromegaly, where the excess growth hormone needs regulation.

Somatostatin analogs

Somatostatin analogs, like octreotide, are designed to behave like the hormone somatostatin in the body. Somatostatin itself is involved in a wide range of activities, such as inhibiting the release of several other hormones, including growth hormone. By creating analogs, scientists have developed more potent and longer-lasting treatments than somatostatin alone.

These analogs are not exact copies of the hormone but are modified to be more effective in medical applications. For instance, while natural somatostatin has a short half-life, analogs are created to ensure they last longer in the body, providing more sustained effects.

Growth hormone inhibition

Growth hormone inhibition is crucial for addressing conditions where there's an overproduction of growth hormone, such as in acromegaly. A primary action of octreotide and other somatostatin analogs is to serve as inhibitors, preventing excessive hormone release and thereby controlling the abnormal growth effects.

Octreotide is particularly effective as it is more potent at inhibiting growth hormone than natural somatostatin. This increased potency allows smaller doses to achieve therapeutic effects, making it a preferred treatment option. This inhibition is vital to prevent and manage symptoms like abnormal growth patterns and metabolic imbalances.

Peptide drugs

Peptide drugs, such as octreotide, are composed of short chains of amino acids. These drugs are similar to proteins, which are made up of longer chains of amino acids. Due to their peptide nature, they have specific attributes that dictate how they can be used in treatment.

The peptide structure of drugs like octreotide emphasizes the importance of the route of administration. Oral ingestion would lead to their digestion before reaching the bloodstream, hence, injections are used to preserve their integrity and functionality.

Peptide drugs are valuable in targeted therapies because they can specifically interact with certain receptors and enzymes in the body. This specificity allows for the modulation of physiological pathways and the treatment of complex disorders, while also minimizing side effects.