Growth hormone is increases by?
**Core Concept**
Growth hormone (GH) is a peptide hormone produced by the pituitary gland that plays a crucial role in growth, cell reproduction, and metabolism. The secretion of GH is regulated by a complex interplay of various factors, including hypothalamic and pituitary hormones.
**Why the Correct Answer is Right**
Growth hormone secretion is stimulated by the hypothalamic hormone Growth Hormone-Releasing Hormone (GHRH) and inhibited by Somatostatin (SST). The GHRH binds to its receptor in the pituitary gland, leading to the release of GH. This process is also influenced by the somatotropic axis, which involves the interaction between GH, insulin-like growth factor 1 (IGF-1), and growth hormone-releasing hormone.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the question.
**Option B:** This option is not correct as it does not directly relate to the regulation of growth hormone secretion.
**Option C:** This option is incorrect as it refers to a different hormone that is not directly involved in the regulation of growth hormone secretion.
**Clinical Pearl / High-Yield Fact**
Growth hormone deficiency can lead to short stature, delayed puberty, and increased risk of metabolic disorders, while excess growth hormone can cause acromegaly, a condition characterized by excessive growth of bones and tissues.
**Correct Answer: D. Growth Hormone-Releasing Hormone (GHRH).**