What is the serum biochemistry test?

Sperm is composed of sperm and seminal plasma. Sperm is produced by testicles, and seminal plasma is composed of secretions from testicles, epididymal cysts, seminal vesicles, prostate glands, and bulbourethral glands. More than 60% of seminal plasma comes from the seminal vesicles, and about 35% comes from the prostate gland. Sperm is like fish, and seminal plasma is like water. The quality of water will seriously affect the quality of sperm. So, what is the test of seminal plasma biochemistry?

What is the serum biochemistry test?

The biochemical examination of seminal plasma is a key indicator for assessing male reproductive function. Male semen is mainly composed of sperm and seminal plasma. There are many key biochemical substances in seminal plasma, which are metabolized by sex hormones or reproductive system, and reflect the role of sex hormones to a certain extent. It plays a very important role in maintaining the normal function of sperm and semen, and has a key application value in the diagnosis of obstructive azoospermia and non-obstructive azoospermia. At present, the common biochemical indicators of seminal plasma in clinical medicine are serum glucose, α-glycylase, serum acid phosphatase, serum sodium citrate, serum extended trypsin, etc.

Common plasma biochemistry tests

Blood pressure plasma zinc measurement. Zinc is a coenzyme of many enzymes in the human body, participating in many metabolic activities, and is called the "flower of life" for men. The male prostate is one of the human organs with the highest zinc content. The average zinc content in the semen of ordinary people is 0.80~2.50Mmol/l, which is 100 times that in the blood. This reflects the necessity of plasma zinc to maintain the activity of male sperm. The measurement of zinc content also reflects the role of the male prostate.

The standard value of zinc concentration in semen is ≥2.4 micromoles of iron in a man's ejaculated semen.

Measurement of blood plasma acid phosphatase. The function of acid phosphatase is to catalyze the hydrolysis of phosphate bonds. It exists in various tissues throughout the body, and is particularly abundant in the male prostate. Almost all acid phosphatase in serum comes from the male prostate. When the male prostate becomes diseased, this enzymatic reaction may change significantly. Therefore, the specificity of serum acid phosphatase is one of the laboratory indicators for the diagnosis of prostate disease.

The basic principle of measurement is that acid phosphatase in refined plasma catalyzes the hydrolysis of p-nitrophenol phosphate under acidic and alkaline conditions to release p-nitrophenol. The latter is light yellow under alkaline conditions and can be measured by colorimetry.

The normal range of acid phosphatase specificity in refined plasma is 48.80~208.60U/ml.

Supplement the measurement of sodium citrate in seminal plasma. The content of sodium citrate in seminal plasma is relatively high, and almost all of it comes from the male prostate. Sodium citrate participates in maintaining the plasma osmotic pressure of seminal plasma, which is related to the sperm survival rate. In addition, it is related to blood cell testosterone, and its composition also reflects the level of blood cell testosterone. The measurement of sodium citrate in seminal plasma has certain practical value for testing prostate function and male sexual function. It can be measured by ultraviolet colorimetry.

The standard value of sodium citrate concentration in a man's ejaculated semen is ≥52 micromoles.

Negative plasma glucose measurement. The glycogen used by male sperm in semen is glucose. And the seminal glucose is metabolized by the seminal vesicles and is affected by the level of testosterone in the blood. Therefore, the measurement of seminal glucose can be used to detect the function of the seminal vesicles and male testicular interstitial cells, and is also helpful for the diagnosis of the cause of azoospermia. There are many ways to measure glucose. The simpler, more sensitive and specific method is the resorcinol staining method. The basic principle is that glucose is insulated with resorcinol at 90°C in an acidic and alkaline natural environment to produce a colored plate nitric oxide synthase, the color intensity of which is proportional to the glucose content.

The standard value of glucose content in refined plasma is 0.87~3.95 g/L.

Neutral α-glucase measurement at term. There are two kinds of α-glucase in seminal plasma, 80% of which is neutral α-glucase, which comes only from the epididymal cyst; 20% is acidic α-glucase, which mainly comes from the prostate. Checking neutral α-glucase is helpful to understand the function of the epididymal cyst (epididymal cyst is the area where sperm matures, the safe passage for sperm movement, the area where sperm is stored, and the place where brittle sperm is processed) and whether the epididymal duct is smooth.

The normal standard value of plasma α-glycase is: 35.10~87.70 U/ml.

Measurement of tubular plasma inhibitory hormone-B. Inhibin is produced by the male testicular somatic cells. Hemostatin-B is the most common indicator for distinguishing male testicular spermatogenesis. Spermatostatin-B is a common indicator for distinguishing whether the ejaculatory duct is smooth.