Testosterone is a veritable human dynamo and a potentate. This steroid hormone is classified as androgen and has been detected in vertebrates. Testosterone primarily being male sex hormone and clinically an anabolic steroid emanates from the secretion of male-testes and of the female ovaries. Testosterone does also find its source, though meagre in quantity, from the adrenal glands, and exerts its high-performance in improving male reproductive tissues like testes and prostate together with the development of secondary sexual features like increased bone, muscle mass and hair growth. Testosterone does not only have got to resist osteoporosis but does maintain a good profile of health and well-being of its producers also. Likewise, the effects of Testosterone extend upto the virilization of sex differences as well as the anabolism of cellular tissues of mammals, birds, reptiles and those of the living-beings having spinal column.

How come Testosterone

Testosterone does have got many key-roles to play in building up human as well as animal metabolism. The functions of anabolism, androgen and virilization span extensively in body organism. The maturation of sex organs, especially of penis, the formation of the scrotum in the fetus, and at the onset of puberty rather during this pubertal period the thickening of vocal chord, growth of moustache, beard and underarm hair, all of them come under the purview of Androgenic influences. On the other hand, increase of muscle mass, of bone density and bone maturation, of body strength, and stimulation of linear growth are influenced by the Anabolism. The secretion of Testosterone varies at every junction of age-strata such as pre-natal stage, early childhood stage, puberty stage, adulthood stage in harmony with its rate of secretion, thereby displaying multiple physiological changes. Let’s have a quick study how all these happen at the on-going stages of aging.

Testosterone At Pre-natal

Androgenic influences (Testosterone) at the pre-birth stage have been diagnosed take place between 7 to 12 weeks of the gestational period. The androgenic activities influence the Sex Identity-creation and the Genital virilization in the field of phallic (male generatative) urethra, scrotal thinning and rugation, midline fusion and phallic enlargement.

Testosterone At Early Childhood

The palpable effects of Testosterone at the stage of early childhood have yet not been strongly felt in male children apart from the brain development or the masculinization of the brain, which clinical studies say takes place due to scarcely perceptible changes or the absence of any noticeable level increase of Testosterone in other areas of body. As of the brain development at this period, there is a distinction between that of male and of female found. Clinical studies say that male brain development occurs at this stage due to the aromatization of Testosterone into the estrogen swimming over the blood-brain barrier, and on the contrary, the alpha-fetoprotein of female fetuses encloses estrogen in order not to affect female brains.

Testosterone At Puberty

The gradual increasing level of androgen at the end of childhood gives rise to two different divisions in terms of their span of influences in metabolism or physiological effects. They are Pre-peripubertal stage and Pubertal stage.

The former (Pre-peirpubertal stage) demonstrates gradual increasing of androgen causing growth of the signs and effects in both sexes like body odour that can be smelt during adulthood, appearance of pubic hair, increased greasy skin and hair casuing skin disorders, growth of underarm hair (axillary hair), ossification of bones, or appearance of moustache or sideburns.

The latter (Pubertal stage) shows more amount of signs and effects in both sexes when androgen is higher. Ironically, females are diagnosed secreting androgen for a prolonged period of heightened levels of free Testosterone in blood more than male lots who develop increasing androgen at a comparatively later stage. However, the signs and effects due to the androgen or developing levels of free Testosterone in blood can be seen in the areas of the growth of Leg hair, the growth of Chest hair, the growth of Underarm hair, decreasing of Subcutaneous facial fat, deepening of Voice, the enlargement of Sebaceous glands or causes of Pimples, enlargement of Adam’s apple, growth of male Fertility, enlargement of phallic or Clitoromegaly, growth of libido and frequency of penile-erection or Clitoral engorgement, Androgenetic alopecia or loss of scalp hair, increased muscle mass and bone density, growth of pubic hair around thighs, growth of jaw, chin, nose, brow and reshape of facial bone contours, broadening of shoulders and expansion of rib-cage along with culmination of bone maturation and completion of growth, those are caused by the Estradiol Metabolites and more palpable in men than in womenfolk.

Testosterone At Adulthood

A run-up in the secretion of Testosterone during adulthood stage for both of male and female sexes have been clinically diagnosed. This maturing stage of life shows the presence of Testosterone counts less in females than in males. Clinical advancements have proved the equal importance of Testosterone counts both when the counts are increasing and are decreasing. For example, decrease in Testosterone counts may lessen the risks of Prostate cancer or increase in Testosterone counts may help prevent the risks of Cardiovascular problems. Anyway, as we age up, we can be diagnosed short of Testosterone counts or its gradual fall, which has two-sided effects physiologically. Besides, Testosterone may be beneficial or a point of well-being to health in case of “Regulating acute HPA (hypothalamic-pituitary-adrenal-axis) response under dominance challenge”, retaining of Muscle Mass, Mental Energy and of Physical prowess, maintaining of the Libido and penile-erection frequency, maintaining of Sperm level and activating genes and promoting the differentiation of Spermatogonia, or in case of controlling Emotional changes during aging.

A clinical study has pointed out to an interesting observation relating to the Testosterone counts that women in relationship with men enjoy the increasing of more Testosterone levels than men. Another study has found that the Testosterone level slopes down when men start fathering their children. This erosion in Testosterone level, the study says, happens at the discharge of emotions towards their children.

Testosterone Effects To Brain

Testosterone has large expansion of effects into the making of Brain, Heart, Liver, and Lung as well as in masculinizing of the grey-area of the Brain, thereby creating distinction between sexes. A female brain has got distinguishing characteristics from a male brain. A male brain does have a more distinctive level of Testosterone than its opposite sex. A revelation made by a Danish research has said that male brain is undoubtedly larger and that has been found consisting of a total myelinated fibre length of 176000 km when that male brain is older by two decades only. On the contraty, a female brain showing a dendritic connections between cells has got a total myelinated fibre length of 149000 km.

Clinical studies as well as common notions are convinced of the fact that human brain has got multiple roles to perform in the build-up of Cognitive ability. The brain of any living-being are influenced by the Testosterone, which in every way affects the functions of memory, attention or spatial ability. Beyond doubt is the fact that decreased or low level of Testosterone secretion causes rather aggravates the miseries of cognition that results gradually into the Dementia of the Alzheimer’s kind. Again, over-secretion and under-secretion of the circulating androgens have turned causing adversely on Cognition.

Revelations of clinical studies disclose that there is curvilinear or quadratic co-relation between spatial performance and the circulation of Testosterone. A study conducted over 43 stout men after having them been administered of supraphysiologic prescribed dosages of Testosterone for consecutive 10 weeks observed no significant and immediate mood and behavioural changes. Again, intensive studies have yet not been able to confirm that there are any far-reaching impacts on improving Alzheimer disease by the administration of Testosterone.

Testosterone After Biogenesis

The origin of biosynthetic Testosterone is from Cholesterol. Cholesterol is the source of other steroid hormones as well. This biogenesis or biosynthesization process, in short and if put simply, takes the oxidative cleavage of the side-chain of the cholesterol by CYP11A, then CYP17A enzyme removes two additional carbon atoms, then 3-beta-HSD oxidizes 3 hydroxyl group and finally, 17-beta-hydroxysteroid dehydrogenase lowers and limits the rate of C-17 keto group androstenedione, and thus the biosynthetic Testosterone is produced.

Male sex produces Testosterone in their testicles in contrary to the their opposite sex who synthsizes and produces Testosterone, though very meagre in quantity, at the thecal cells of the ovaries by the placenta and by the zona reticularis of the adrenal cortex. Lydig cells produce Testosterone in the testicles and Spermatogenesis in Sertoli cells which is found in male-generative glands needs Testosterone. The activities of Testosterone are set towards emboldening tissues in blood, thereby strengthening Plasma protein and SHBG (sex hormone binding globulin).

Testosterone’s Effects

Testosterone is predominantly a male reproductive hormone and has source from testes in male sex and in the thecal cells of the ovaries. Testosterone has got a lot of effects in human bodies as well as in other vertebrates. Testosterone has shown two main roles playing there as found till to this date. Testosterone has been found to be activating Androgen receptor and converting to Estradiol, and found to be activating specific Estrogen receptors.

Testosterone is ‘not bound’ (free-T) and is carried to the Cytoplasm of the target tissue cells. Testosterone at these target tissue cells can bind to the androgen receptor or can be minimized to 5-alpha dihydrotestosterone (DHT) by the 5-alpha reductase. That androgen receptor is bound by the DHT more strongly than the free-Testosterone and a five times more androgenic potency has been found.

Testosterone is an androgenic hormone which causes the development and normal nourishment of male sex and of male generative systems such as penis, testes, scrotum, prostate, and seminal vesicles together with the development of secondary sexual characteristics such as increased bone, muscle mass or musculature,hair growth, laryngeal enlargement and deepening of voice. Added to these, Testosterone at its normal level of secretion keeps up vim, vigour and virility along with high energy level, positive attitude, fertilization capability, fat distribution and sexual urge.

Testosterone Metabolism

The cytochrome P450 enzyme 5-alpha reductase proves to be an important sex accessory organ and responsible for hair follicles. Interestingly, about 7% of Testosterone is found lessened by this enzyme and another 0.3% of Testosterone (approx.) has been found into the form of Estradiol by CYP19A1 (aromatase) that has got to find place in brain, liver and adipose tissues. Dihydrotestosterone (DHT) has important role in metabolism and is more potent form of Testosterone such as Masculinization as opposed to the activities of Estradiol such as Ferminization. Deactivation of Testosterone and DHT is found when enzymes hydroxylate at the positions like 6,7,15 or 16.

Testosterone Deficiency

The more one ages, the less Testosterone is produced. Testosterone Deficiency (TD) or low count in Testosterone is the cause of low level of secretion of hormones from the pituitary gland, or hypothalamus for many reasons or low level of testosterone secretion from the Testes that hinder the rate of secretion. Testosterone deficiency or low level of testosterone secretion is called Hypogonadism. Testosterone Replacement Therapy is believed to be effective and congenial at par for recovering the lost fettles of human bodies.

Testosterone deficiency may lead to many diseases and damages to the functioning of body organisms. No sooner does the level of testosterone secretion reduce than diminized virility, weakening of bones, loss of muscle mass, or non-performing genitalia without full growth may appear as symptoms suffering from Testosterone Deficiency (TD).

Secretion of Testosterone from testes is regulated by a complex chain of honest signalling originating from the brain. That complex chain has been named as HPGA (Hypothalamic-Pituitary-Gonadal Axis). The course of Testosterone secretion is very interesting. Hypothalamus secrets GnRH (gonadotropin-releasing hormone) to the Pituitary gland in carefully timed pulses or bursts that activate the production of LH (leutenizing hormone) from the Pituitary gland. LH accelerates the production of Testosterone from the Leydig cells. Clinical diagnoses have found that normal production of Testosterone from testes is between 4 to 7 milligrams per day. Furthermore, those diagnoses have established that production of Testosterone from testes is higher during Puberty than during adulthood period after the age of 50. The age factors work provably in increasing and decreasing of the production of Testosterone as the obesity, hepertension, diabetes, peer-pressures at workplaces are no less responsible causes.