Stress is a condition that tends to disturb the equilibrium of the individual with the environment. There are hormonal changes which occur during stress and have their impact in the endocrine system.
Reaction to stress is associated with increased hormone secretions of several hormones such as glucocorticoids, growth hormone, prolactin and catecholamine. The elevated levels of these hormones increase the risk of infections and also decrease the innate immunity as well as increase the autoimmune responses.
There are endocrine disorders related with the increased hormone secretion during stress conditions such as psychosexual dwarfism, obesity, Grave’s disease and gonadal dysfunction. The effect of increased secretion of the hormones is increase in mobilization of energy and adaption of the individual to current circumstances.
Activation of the pituitary adrenal axis is an important and dominant response due to stress. On stimulation of the pituitary adrenal axis results in hypothalamic secretion of the CRF (corticotrophin-releasing factor) which further stimulates the pituitary to ACTH, 3-endorphin and 8-lipotropin.
During stress, the plasma levels of these hormones increase up to five times.
The stimulation of the pituitary adrenal axis is also associated with the release of hormone catecholamine. The increased level of catecholamine leads to increased skeletal muscle flow of blood increased cardiac output and glucose levels, bronchiolar dilation, cutaneous vasoconstriction etc.
Acute stress releases vasopressin rapidly from the Para ventricular nucleus of hypothalamus together with corticotrophin releasing hormone.
During stress there is also suppression of gonadotropins and gonadal steroidal hormones which disrupt the normal menstrual cycle and prolonged stress can also lead to impairment of reproductive functions.
Thyroid functions are down regulated during stress conditions. T3 and T4 levels decrease whenever there is any stress condition.
The growth hormone level increases due to physical stress and prolactin level may increase or decrease depending on the conditions of regulatory environment locally.
