The prostate (from Greek προστάτης – prostates, literally "one who stands before", "protector", "guardian") is a compound tubuloalveolar exocrine gland of the male reproductive system in most mammals.The function of the prostate is to secrete a slightly alkaline fluid, milky or white in appearance, that usually constitutes 50–75% of the volume of the semen along with spermatozoa and seminal vesicle fluid.
Semen is made alkaline overall with the secretions from the other
contributing glands, including, at least, the seminal vesicle fluid. The
alkalinity of semen helps neutralize the acidity of the vaginal tract,
prolonging the lifespan of sperm. The alkalinization of semen is
primarily accomplished through secretion from the seminal vesicles.
PSA is an acronym for “prostate specific antigen,” a protein made specifically by the prostate gland (gamma-seminoprotein or kallikrein-3 (KLK3), is a glycoprotein enzyme encoded in humans by the KLK3 gene). The biological role of the prostate is to contribute fluids and proteins to semen at ejaculation. The other glands that contribute fluids and proteins to semen are the seminal vesicles. The prostate and seminal vesicles contract at ejaculation; the seminal vesicles contribute proteins that are extremely large, making semen thick, thus concentrating the sperm in the vagina, close to the cervix, the opening to the uterus. PSA is a specific type of protein, an enzyme, that is capable of breaking up the large seminal vesicle proteins, making them shorter and less viscous, allowing the sperm to swim free of the ejaculate, through the cervix into the uterus and fallopian tubes in search of an egg.
Prostate-specific antigen is a misnomer: it is an antigen
but is not specific to the prostate. Although present in large amounts
in prostatic tissue and semen, it has been detected in other body fluids
and tissues.
(In women, PSA is found in female ejaculate at concentrations roughly equal to that found in male semen. Other than semen and female ejaculate, the greatest concentrations of PSA in biological fluids are detected in breast milk and amniotic fluid. Low concentrations of PSA have been identified in the urethral glands, endometrium, normal breast tissue and salivary gland tissue. PSA also is found in the serum of women with breast, lung, or uterine cancer and in some patients with renal cancer.)
Contradictory role of PSA as disease indicator: PSA is present in small quantities in the serum of men with healthy prostates, but is often elevated in the presence of prostate cancer or other prostate disorders. PSA is not a unique indicator of prostate cancer, but may be detect also prostatitis or benign prostatic hyperplasia.
PSA is produced in the epithelial cells of the prostate, and can be demonstrated in biopsy samples or other histological specimens using immunohistochemistry. Disruption of this epithelium, for example in inflammation or benign prostatic hyperplasia, may lead to some diffusion of the antigen into the tissue around the epithelium, and is the cause of elevated blood levels of PSA in these conditions.
More significantly, PSA remains present in prostate cells after they
become malignant. Prostate cancer cells generally have variable or weak
staining for PSA, due to the disruption of their normal functioning.
Thus, individual prostate cancer cells produce less PSA than healthy
cells; the raised serum levels in prostate cancer patients is due to the
greatly increased number of such cells, not their individual activity.
Another self contradictory biological role prostate as immune suppressor for itself: for the proteins and fluids contributed by the prostate to ejaculated semen is to block negative responses to sperm by cells of the immune system in the vagina to protect the female reproductive organs from bacterial infection. Laboratory studies by Bedford Research scientists have shown that even very small amounts of semen added to cultures of immune cells causes them to die within 24 hours. It seems possible that this suppression of immune response to protect sperm has the unwanted side effect of making the prostate gland itself “immune suppressed” and thus less capable of protecting itself from infections and cancer. Some men suffer from low grade infections of the prostate for years, a condition known as “chronic prostatitis.” Other men may also have chronic prostatitis, but without symptoms. Some studies indicate that chronic, low-grade infections can eventually lead to cancer.
PSA is an acronym for “prostate specific antigen,” a protein made specifically by the prostate gland (gamma-seminoprotein or kallikrein-3 (KLK3), is a glycoprotein enzyme encoded in humans by the KLK3 gene). The biological role of the prostate is to contribute fluids and proteins to semen at ejaculation. The other glands that contribute fluids and proteins to semen are the seminal vesicles. The prostate and seminal vesicles contract at ejaculation; the seminal vesicles contribute proteins that are extremely large, making semen thick, thus concentrating the sperm in the vagina, close to the cervix, the opening to the uterus. PSA is a specific type of protein, an enzyme, that is capable of breaking up the large seminal vesicle proteins, making them shorter and less viscous, allowing the sperm to swim free of the ejaculate, through the cervix into the uterus and fallopian tubes in search of an egg.
(In women, PSA is found in female ejaculate at concentrations roughly equal to that found in male semen. Other than semen and female ejaculate, the greatest concentrations of PSA in biological fluids are detected in breast milk and amniotic fluid. Low concentrations of PSA have been identified in the urethral glands, endometrium, normal breast tissue and salivary gland tissue. PSA also is found in the serum of women with breast, lung, or uterine cancer and in some patients with renal cancer.)
Contradictory role of PSA as disease indicator: PSA is present in small quantities in the serum of men with healthy prostates, but is often elevated in the presence of prostate cancer or other prostate disorders. PSA is not a unique indicator of prostate cancer, but may be detect also prostatitis or benign prostatic hyperplasia.
PSA is produced in the epithelial cells of the prostate, and can be demonstrated in biopsy samples or other histological specimens using immunohistochemistry. Disruption of this epithelium, for example in inflammation or benign prostatic hyperplasia, may lead to some diffusion of the antigen into the tissue around the epithelium, and is the cause of elevated blood levels of PSA in these conditions.
Another self contradictory biological role prostate as immune suppressor for itself: for the proteins and fluids contributed by the prostate to ejaculated semen is to block negative responses to sperm by cells of the immune system in the vagina to protect the female reproductive organs from bacterial infection. Laboratory studies by Bedford Research scientists have shown that even very small amounts of semen added to cultures of immune cells causes them to die within 24 hours. It seems possible that this suppression of immune response to protect sperm has the unwanted side effect of making the prostate gland itself “immune suppressed” and thus less capable of protecting itself from infections and cancer. Some men suffer from low grade infections of the prostate for years, a condition known as “chronic prostatitis.” Other men may also have chronic prostatitis, but without symptoms. Some studies indicate that chronic, low-grade infections can eventually lead to cancer.
#share courtesy:
*http://www.bedfordresearch.org
*wikipedia.org
*encyclopedia britanica, inc.
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