Apocrine Secretion: Function, Role & Diseases

Apocrine secretion corresponds to secretion in vesicles. This mode of secretion is relatively rare and occurs primarily in the apical sweat glands. In sweat gland abscess, the affected skin regions are inflamed and trigger fistula formation.

What is apocrine secretion?

The minor glands of the eyelid follow this mode of secretion, and when inflamed, stye formation may occur. In medicine, the term secretion refers to the secretion of a secretion. Glands and gland-like cells are either exocrine or endocrine. In endocrine glands, secretion occurs through exit lymphatic ducts. In exocrine glands, secretion does not occur via ducts, but secretion is delivered to the body surface or to a body cavity. Exocrine secretion can occur in a variety of ways. In this context, we also talk about the secretion modes of exocrine glands. Apocrine secretion is one of a total of three secretion modes followed by exocrine glands and gland-like cells in the human organism. In this mode, the glandular cell constricts secretion from a portion of its cell membrane, which, together with the apical cytoplasm of the immediate environment, forms individual vesicles and is consumed in this process. From this rather rarely occurring mode, the eccrine and holocrine modes are to be distinguished. Apical modes, in turn, are present primarily in the mammary glands and in the prostate or seminal vesicle. The scent glands of human skin also follow the apocrine mode.

Function and task

Secretions perform many different tasks in the human body. For example, endocrine secretions are hormonally active and influence the control of various body processes. Exocrine secretions in the apocrine mode fulfill a function particularly as sexual secretions. For example, the seminal vesicle of the male produces a protein. This protein is known as semenogelin and encloses the sperm in a matrix of gel. This protects the sperm and prevents premature decay. Thus, the secretion of the seminal vesicle ultimately ensures the continuation of the human body by supporting reproduction. The secretion occurs partly by eccrine exocytosis and to some extent by apocrine processes. Apocrine secretion is delivery in secretory vesicles. These vesicles correspond to fat droplets that accumulate toward the lumen in the cell membrane of the glandular cells. Apocrine glands have an extra lumen compared to eccrine glands and bear tiny protrusions of the apical cell membrane at the cell pole. The accumulated lipid droplets do not fuse with the glandular cells but remain secreted. The secreted droplets eventually bind circumferentially to integral membrane proteins, such as those found as butyrophilins in the cell membrane. This binding causes the lipid droplets to bulge continuously into the lumen of the gland. Below this bulge, the membrane of the gland cell gradually contracts. Thus, not only is the fat plug sequestered, but also the surrounding cytoplasm and the attached cell membrane on the outside of the cell. The secretion is thus packed into membrane containers. This process is also known as apocytosis and causes the glandular cells to lose cytoplasm and cell membrane. The volume of the cells decreases as a result of this process, which distinguishes the secretion mode from eccrine secretion. The secretion is released from the cell only when the former cell membrane ruptures. In addition to the seminal vesicle, the mammary gland engages in apocrine secretion. This secretion corresponds primarily to the release of fat from the mammary epithelial cells. In addition, the minor glands of the eyelid also follow this mode of secretion, which are sweat gland-like apocrine glands of the eyelid margin. Apocrine sweat glands also occur under the armpits, in the genital area and anus, and on the nipples. These glands are actually scent glands that secrete pheromones and thus influence sexual behavior to some degree.

Diseases and ailments

Especially in the secretion by the apocrine scent glands of the woman can be strong fluctuations, which in all cases have no disease value, but are more or less dependent on the cycle. Since the scent glands produce a fatty secretion, they are also particularly susceptible to infections. Such infections can disrupt the local protective mantle of the acid.If, in turn, the protective alkaline mantle experiences a disturbance, the affected area becomes more susceptible to bacterial infections. For this reason, infections frequently occur on the scent glands, which usually manifest themselves in the form of abscesses. In this context, there is also talk of a sweat gland abscess. Such abscesses are accompanied by inflammation and fistula formation. This disease is sometimes also referred to as acne inversa, which mainly affects people in puberty. The apocrine sweat glands become inflamed only secondarily. Originally, the inflammation originates from the holocrine sebaceous glands of these skin areas. Acne inversa is extremely painful. Extensive phlegmon may develop in the connective tissue under the skin, causing a bluish discoloration and may even lead to sepsis on larger areas. Since the apocrine sweat glands are predominantly responsible for personal body odor, they may also be affected by bromhidrosis. In this phenomenon, an excessively strong body odor sets in due to an increase in the local germ flora. The body odor is caused by a metabolism of the sebaceous secretion by the body’s own bacteria and thus increases above all when increased sweat production moistens the horny layer of the skin and thus promotes bacterial proliferation. Various diseases, but also psychological stress, are possible causes of increased sweat production. The apical glands of the breast and prostate, on the other hand, are frequently involved in benign as well as malignant tumor diseases.